The trio of lakes in this striking image each have a different color thanks to a combination of factors including depth, water chemistry and inhabiting wildlife. This is very strange, not only because of the lakes' proximity but because in the not-too-distant past (geologically speaking), they were once part of the same ancient lake, according to NASA's Earth Observatory.

The three lakes are Lake Shala, which has a deep-blue hue; Lake Abijata, which is green; and Lake Langano, which has a sandy-yellow hue similar to the surrounding landscape. The trio is located in Ethiopia's Great Rift Valley, around 125 miles (200 kilometers) south of the country's capital, Addis Ababa. 

Related: 12 amazing images of Earth from space

Lake Shala is around 7.5 miles (12 km) long and 17 miles (28 km) across at its widest point. It is the deepest of the three lakes, with a maximum depth of 873 feet (266 meters), which is why its waters appear dark blue from above. It is a soda lake, meaning it is highly alkaline (has a very high pH). Despite the extreme conditions, the lake contains a large number of small crustaceans and microorganisms that support large flocks of visiting flamingos and pelicans.

Lake Abijata, which is around 11 miles (17 km) long and 9 miles (15 km) wide, is the shallowest of the three lakes, with a maximum depth of 46 feet (14 m). As a result, it is highly variable and has lost around one-third of its area over the last 50 years. The lake's green color is most likely due to a bloom of phytoplankton on its surface, which also attracts a large number of birds. 

Lake Langano is around 11 miles (18 km) long and 10 miles (16 km) across. It is fed mostly by streams to the east, which dump brown sediment from nearby mountains into the water — giving it its yellow color. Langano is a popular destination for beachgoers because it is the only lake in the area not inhabited by parasitic worms that can transmit a potentially fatal disease known as schistosomiasis.

However, until around 10,000 years ago, the three lakes were part of a single massive body of water, named Lake Galla, which disappeared after changing rainfall patterns and tectonic motion altered the surrounding landscape.

An explosive, green comet racing toward Earth is currently zooming past the nearby Andromeda galaxy in the night sky, setting the stage for some stunning photographs. You can also watch the comet fly past our spiralling galactic neighbor in real time, thanks to an upcoming livestream.

Comet 12P/Pons Brooks (12P), also known as the devil comet, is a 10.5-mile-wide (17 kilometers) comet that circles the sun on a highly elliptical orbit every 71 years or so. 12P is a cryovolcanic, or ice volcano, comet. This means that it occasionally erupts when solar radiation cracks open its icy shell, or nucleus, allowing it to shoot out a combination of ice and gas, known as cryomagma, into space. When this happens, the cryomagma massively expands 12P's coma — the cloud of gas and dust surrounding the nucleus — making the comet appear much brighter for the next few days. 

In July 2023, astronomers watched 12P blow its top for the first time in almost 70 years, and it has erupted reasonably frequently ever since. During the comet's early eruptions, 12P's expanded coma grew lopsided thanks to a notch in its nucleus, making it look like it had grown a pair of demonic horns. However, following more-recent eruptions, the horns seem to have disappeared for good. Newer photos of the comet also show that it has developed a green glow, which is caused by high levels of dicarbon (two carbon atoms stuck together) in its coma and tail, which is quite rare.

12P is expected to make its closest approach to Earth on June 2 after first slingshotting around the sun in late April. After it passes us, it will then journey back into the outer reaches of our cosmic neighborhood, where it will spend a majority of the next 70 years.

As it continues to hurtle toward the inner solar system, 12P can now be spotted in the same part of the night sky as the Andromeda galaxy — a spiral galaxy located around 2.5 million light-years from the Milky Way, which is destined to collide with our own galaxy in around 4.5 billion years. 

You can watch this extremely rare conjunction (an astronomical phenomenon that occurs when two objects appear close in the sky, despite being trillions of miles apart) take place in real time thanks to livestreams from the Virtual Telescope Project, which will showcase the cosmic spectacle as seen from the project's observatory in Manciano, Italy from 2:30 p.m. ET on Sunday (March 10) and Tuesday (March 12).

Related: Related: In a 1st, scientists predicted that volcanic comet was due to pop 'like a Champagne bottle' — and it did

For now, the wide conjunction is most clearly visible just above the horizon after sunset, according to Spaceweather.com. Andromeda is visible to the naked eye with clear skies but you will need a good telescope, camera or decent pair of stargazing binoculars to spot 12P, which is around 10 degrees below the galaxy. (That's approximately the same width as your fist when held up to the sky, according to Time and Date.)

The Virtual Telescope Project has already captured a stunning long-exposure shot of 12P and Andromeda shining side-by-side (see above). 

Astrophotographer Petr Horálek, has also captured a series of stunning images of the pair from Slovakia. The Triangulum galaxy (M33) and the star Mirach, often used as a "guide" to find Andromeda, are also clearly visible in these photos.

This is not the first time that 12P has photobombed a cosmic structure: In January, the comet passed in front of the Crescent Nebula — a massive cloud of ionized red gas located 5,000 light-years from Earth.

Astrophotographers are also hoping to snap the comet during the upcoming total solar eclipse on April 8, when 12P will be orientated very close to the temporarily obstructed sun. If it erupts in the days leading up to the eclipse, the comet may also be visible to the naked eye during totality.

Venus briefly flashed a shimmering green light in the night sky above Sweden, new footage reveals. The rarely seen phenomenon is almost identical to the ethereal green flashes that are occasionally seen around the sun during sunrises and sunsets. 

Photographer Peter Rosén captured the colorful flash coming from one of our closest planetary neighbors while he was watching Venus rise above the horizon in Stockholm in the early hours of Jan. 8, Spaceweather.com reported. 

The bright flash, which lasted for around a second, was an "unexpected bonus" that added to what was already an awe-inspiring experience, Rosén told Spaceweather.com.

Similar green flashes are occasionally seen coming from the sun as the sun rises above an ocean horizon. The light shows are caused by light from the celestial objects being refracted, or split apart, as it passes through our planet's atmosphere. 

Related: 10 bizarre phenomena that lit up the sky (and their scientific explanations)

Visible light is made up of different wavelengths of colored light, which collectively give the rays a white color. But when light from the sun shines through Earth's atmosphere, the individual wavelengths get partially refracted by gas molecules. This happens all the time: For example, the daytime sky appears blue because blue wavelengths scatter more than any other wavelength. 

However, with the right conditions, such as clear skies, light from the sun and nearby planets can fully separate, especially when they are positioned near the horizon because the light has to travel through more of the atmosphere to reach the observer. 

When this happens, shorter wavelengths of light, such as blues and violets, are scattered the most, while longer wavelengths, like reds, oranges and yellows, are more readily absorbed by molecules in the atmosphere. As a result, mid-length green wavelengths are sometimes the only colors that reach an observer. However, the angle has to be just right for this to happen, which is why it only appears to the observer as a brief flash.

In the recent footage of Venus, green is the most prominent color that flashes from the planet. But if you look closely you can also see yellow, orange, red and blue light shimmer around as well.

In some circumstances, ice crystals can also refract sunlight in the atmosphere to create rainbow-colored clouds and halos of light around the sun or moon. The same effect can also create rainbow rings around objects as light is refracted by large grains of floating pollen.

Green flashes have been spotted coming from Venus a handful of times before. Similar green flashes have also been captured in images of Mercury and the moon.

But unlike green flashes around the sun, which appear more frequently in the clear air above the ocean, these light shows are more commonly seen through extremely cold air, which magnifies the effect. This means planetary flashes are not so tightly constrained to the horizon, according to Spaceweather.com.

The massive volcanic "devil comet," that is racing toward the sun may have lost the distinctive horns that earned it its sinister nickname. Last week, after the comet's latest and most violent outburst yet, its trademark head spikes did not appear as they did after previous eruptions. But astronomers have spotted several new characteristics of the comet, including a rare green hue and a mysterious "shadow."

Comet 12P/Pons-Brooks (12P), is a massive 10.5-mile-wide (17 kilometer) comet that is on course to make its closest approach to Earth for more than 70 years next summer. Comet 12P is a cryovolcanic, or cold volcano, comet that consists of an icy shell, or nucleus, filled with ice and gas. When the comet soaks up enough of the sun's radiation, its frosty innards, or cryomagma, get superheated. Pressure builds up within the nucleus until the shell cracks and the comet's icy guts spray into space. After an eruption, the comet's coma — a fuzzy, reflective cloud of cryomagma and dust — expands and makes the comet appear much brighter to astronomers as it reflects the sun's rays.

So far, 12P has had three major eruptions: On July 20, when it was spotted exploding for the first time in 69 years; on Oct. 5, when it erupted even more vigorously; and on Halloween (Oct. 31), which was a less intense outburst. Each time the comet blew its top, its coma expanded into an irregular shape with a "dark lane" that made it appear to have grown a pair of horns.

On Nov. 14, 12P experienced another major eruption — the most extreme outburst so far. Astronomers watched as the comet temporarily became more than 100 times brighter than normal in the following days as its coma expanded, Spaceweather.com reported. But this time, its distinctive horns were nowhere to be seen. 

"The coma seems perfectly circular this time," Nick James, director of the British Astronomical Associations's (BAA) comet section, told Spaceweather.com.

Related: 'Bouncing' comets may be delivering the seeds of life to alien planets, new study finds

The comet's horns are the result of an irregularity in the shape of 12P's nucleus, BAA astronomer Richard Miles previously told Live Science. The outflowing gas is likely being partially obstructed by a notch sticking out on the nucleus, he said.

It is currently unclear why the horns have disappeared. But the frequent eruptions may have destroyed the notch that was blocking the outflow of cryomagma. During the third eruption on Halloween, the horns were much less distinct that they were in the first two eruptions, which suggests that notch may have already been damaged after the comet's first two outbursts.

Amateur astronomer and photographer Eliot Herman, who has been taking daily photos of the comet since its first eruption, told Live Science that he was surprised when the coma expanded without sprouting its horns and is unsure if they will make another appearance in the future. "The devil may be gone [for good]," he said.

Herman's images also revealed another surprise — a green hue in the comet's coma. This rare coloration is given off by comets with high levels of dicarbon, a chemical that emits green light when broken down by sunlight, according to Science magazine.

Several green comets have flown by Earth this year, including the "green comet" C/2022 E3 (ZTF), which made its closest approach to Earth for 50,000 years in February, and Comet Nishimura, which flew by our planet for the first time in 430 years in September.

In follow-up images of the comet, Herman also noticed another strange dark patch in the comet's colorful coma, which looks like a curved gap. But unlike the misshaped dark lane that previously gave the coma its horns, experts believe that this unusual shape is a shadow cast by the outflowing cryomagma, according to Spaceweather.com. 

12P is currently speeding toward the sun at around 40,000 mph (64,300 km/h) as it nears the end of its 71-year orbit around the sun, according to Live Science's sister site Space.com.  

On April 24, 2024, the comet will reach its closest point to the sun, or perihelion, before being slingshotted around our home star and into the outer solar system where it spends a majority of its orbit. It likely won't return to the inner solar system until 2094.

12P will make its closest approach to Earth on June 2 next year, when it will hopefully be visible to the naked eye.

A recent solar storm smashed into Earth and created what appeared to be bright pumpkin-colored pillars dancing in the night sky above Canada, a haunting new photo reveals. But there is a problem with the image: Orange-colored auroras should not exist. 

Instead of impossible auroras, the image actually captured a rare mix of red and green lights that hasn't been this visible since a monstrous Halloween solar storm smashed into Earth 20 years ago, experts say. 

"The orange was sublime, just incredible," aurora photographer Harlan Thomas told Spaceweather.com. "The pillars in the center stayed there glowing for more than 20 minutes."

Thomas captured the colorful shot on Oct. 19 above a pond to the west of Calgary in Alberta, around three days after the sun launched a hefty, slow-moving coronal mass ejection (CME) toward Earth. 

Related: 10 bizarre phenomena that lit up the sky (and their scientific explanations)

Auroras are created when high-energy particles from CMEs or solar wind bypass Earth's magnetic shield, or magnetosphere, and superheat gas molecules in the upper atmosphere. The excited molecules release energy in the form of light, and the color of that light depends on which element is being excited. The two most common aurora colors are red and green, which are both given off by oxygen molecules at different altitudes (red auroras are produced at higher altitudes than their green variants). But when the solar particles penetrate deep into the atmosphere, they can also trigger rare pink auroras when they excite nitrogen molecules.

Theoretically, both oxygen and nitrogen molecules can give off orange wavelengths under specific conditions. However, even when this happens, the orange is overwhelmed by the other colors given off by the molecules surrounding it, making it practically impossible to see these wavelengths, Spaceweather.com reported.

So how do we see this color in the latest image?

"There can be a mixing of the two processes [red and green auroras], which fools the camera and eye to believe that it is orange," Kjellmar Oksavik, a space weather scientist and aurora expert at the University of Bergen in Norway, told Spaceweather.com. "In reality, it is both red and green at the same time."

Despite red and green auroras frequently occurring together in the sky, "orange" auroras are very rare. The orange color is most visible at the center of large auroral rays — vertical pillars of light that align along invisible magnetic field lines — that are made up of both red and green light, which are very uncommon, Oksavik said.

The last time such vibrant pumpkin-like hues were spotted was the great Halloween storm of 2003 — the most powerful solar storm in modern records, Spaceweather.com reported. During this epic event, the orange lights were spotted across North America and northern Europe.

A 64-year-old man got a medical checkup after his tongue began sprouting green "hairs." The bizarre-looking fuzz turned out to be caused by a fairly common and harmless condition known as hairy tongue.

The patient's tongue had turned green about two weeks before he visited the clinic, shortly after he had completed a course of antibiotics for a gum infection. When the discoloration initially appeared, doctors suspected a case of oral thrush, a kind of fungal infection, and prescribed an antifungal treatment, but this did nothing to curtail the moss-like growths.

Upon closer inspection, physicians noticed that the man's filiform papillae — the tiny, cone-shaped bumps that cover the surface of the tongue and give it its rough texture — were longer than what would be expected on a healthy tongue. The doctors saw no other signs of injury or disease and the patient reported no pain or change in his sense of taste.

"A diagnosis of hairy tongue was made," physicians wrote in a case report published July 6 in the New England Journal of Medicine. Hairy tongue, or lingua villosa, is a benign condition that causes hair-like growths of various colors to sprout on the top of the tongue, they added.

Related: Boy's bright-yellow tongue was a sign of rare disorder

These growths are filiform papillae that haven't shed as they normally would when they come in contact with rough objects, such as a toothbrush, tongue scraper or solid, textured foods. Typically, the papillae grow to a fraction of an inch (1 millimeter) before they fall off "like a layer of skin being shed" in a process known as desquamation, according to the Cleveland Clinic.

When they are not regularly shorn off, the papillae can grow up to 0.7 inches (18 millimeters) long and lead to hairy tongue. The condition affects about 13% of people at some point in their lives, the majority of cases being in men and patients over 65, according to the American Academy of Oral Medicine.

As the bumps grow into hair-like fibers, they collect bits of food, bacteria, dead skin cells and other gunk that give the furry tongue its color. "Hairy tongue may appear brown, white, green, or pink, depending upon the specific cause and other factors, such as mouthwashes or even candy," the American Academy of Oral Medicine states.

And frequently, hairy tongue manifests as jet black fuzz, a condition specifically known as lingua villosa nigra, or black hairy tongue, according to the case report. 

Risk factors for developing a hairy tongue of any color include eating a diet of soft foods and from drinking large amounts of coffee, tea or alcohol. Other risk factors include smoking, dehydration, poor oral hygiene and use of oral medication that can shift the population of microbes in the mouth, according to the case report. Brushing the tongue regularly is a good way of preventing the papillae from becoming elongated and discolored.

Physicians advised the green-tongued patient to gently scrub his tongue with a toothbrush four times daily and to stop smoking. "At 6-month follow-up, the tongue appearance had returned to normal despite the patient continuing to smoke," the doctors wrote in the case report.

A camera attached to a telescope on Hawaii's tallest peak recently captured footage of a series of eerie, bright green lines that shot across the night sky for just over a second. Experts say the unexpected light show resulted from a rapid burst of lasers fired toward Earth by a NASA spacecraft. 

The laser lines appeared on Jan. 28, flashing across the sky one by one in just over one second. A video of the lasers was captured by the Subaru-Asahi Star Camera — co-owned by the National Astronomical Observatory of Japan (NAOJ) and Japanese news agency Asahi Shimbun — attached to the Subaru telescope on top of Mauna Kea, a dormant volcano on Hawaii's Big Island. 

A time-lapse image of the lasers firing next to one another has drawn online comparisons with "digital rain," or the lines of green computer code that fall vertically down the screen during the Matrix movies. But instead of being a glitch in a simulated reality, the lasers were actually emitted by a device onboard NASA's ICESat-2 satellite, NAOJ representatives wrote on Twitter. 

ICESat-2 tracks changes in the cryosphere — the part of Earth covered by solid precipitation including snow, sea ice, lake and river ice, icebergs, glaciers, ice sheets, ice shelves and permafrost — and cloud cover caused by human-driven climate change. To do this, the satellite uses an altimeter (a gadget that measures altitude) to fire bright lasers toward Earth's surface, then measures how long it takes for those lasers to bounce back to the satellite's dish. The altimeter onboard ICESat-2, known as the Advanced Topographic Laser Altimeter System (ATLAS), is one of the most powerful ever made: It is capable of firing 10,000 green laser pulses per second, which allows the device to collect measurements every 2.3 feet (0.7 meters) across Earth's surface, according to the ICESat-2 website.

Related: Bizarre blue blobs hover in Earth's atmosphere in stunning astronaut photo. But what are they?

The ethereal green lines that appear in the video are a result of some of these laser pulses, each of which is made up of around 20 trillion photons, lining up exactly with the camera's lens. 

Perfectly positioned 

The laser light show is not the only unusual spectacle to be captured by the Subaru-Asahi Star Camera in the past month. 

On Jan. 18 an eerily perfect "whirlpool" of light in the shape of a spiral galaxy briefly appeared above Mauna Kea. Experts later discovered that the luminous spiral was the result of sunlight shining through a cloud of frozen rocket fuel that was ejected by a SpaceX rocket, shortly after it deployed a military GPS satellite and before it came crashing back down to Earth. 

The camera also captured another one of these "SpaceX" spirals shimmering over Hawaii in April 2022.

The summit of Mauna Kea is 13,803 feet (4,207 m) above sea level, which makes it the tallest point in Hawaii. Due to its lofty altitude, the Subaru-Asahi Star Camera has a near-uninterrupted view of the cosmos. As a result, it is in a prime location to detect unusual visual phenomena in the night sky. 

Whether you love a challenging hike, hot HIIT session or heavy weights workout, the best water bottles can help you stay hydrated.

Plus, having a reusable water bottle you like can encourage you to drink more water, and helps to reduce single use plastic. The best water bottles are durable, leak-proof and available in multiple shapes and sizes.

“Many of us have several water bottles gathering dust in our kitchen cupboards. Pick a water bottle that meets your needs, and you enjoy drinking from, and you’ll have a much better chance of staying hydrated,” Elliot Hansoon, personal trainer and founder of EH Coaching, told Live Science.

Around 60 percent of the body is made up of water and it plays a crucial role in every bodily function - delivering nutrients to cells, aiding digestion, helping us maintain a healthy temperature and keeping joints well lubricated and mobile.

It’s important to stay hydrated both before, during and after exercise as it helps the body function properly. When we exercise we lose a lot of fluid, and this needs topping up to avoid dehydration. Drinking water post-workout can help reduce the risk of Delayed Onset Muscle Soreness, aka DOMS.

Our testers at Live Science have rigorously tested some of the best water bottles on the market, looking at price, size, insulation, drinking spout design and if they are leakproof. Choose a bottle you like and you are more likely to keep your hydration levels up. Read on to find out about our pick of the best water bottles.

Mind you, we are no longer updating this guide with new products. If you want to check out the latest reviews of water bottles, head on over to our sister websites!

The best water bottle we've tried

YETI has a rep for making robust quality products that are high performing and built for everyday use. We’re pleased to say this is no exception with the YETI Rambler 26 oz. bottle with chug cap. Made from stainless steel, the double walled vacuum bottle is designed to keep drinks hot or cold.

It comes with a screw lid and carry handle, and a chug cap – or drinking spout – that has a steady water flow. We like that the lids are all interchangeable among the other Rambler bottles, that range in size from 12 to 64 ounces. It is also dishwasher-friendly, which seems to be a rarity when it comes to insulated water bottles. The Rambler’s wide mouth also means it is really easy to wash by hand, or put ice cubes into without having to crush them up first.

It’s slightly heavier and bulkier than your average water bottle, compared with other hiking style ones, and it’s not cheap ($99 / £99), but if you want something that looks as good as it performs, then this is a great choice.

Best water bottle for gym goers

The Takeya Actives Insulated Bottle not only looks good and boasts a sweat-free grip that makes it perfect for gym use, the double-wall design of this 18/8 stainless steel bottle will keep your drink cold throughout a workout and beyond (24 hours in fact).

It's slightly heavier than some similarly designed bottles, but has a wide handle that makes it comfortable to carry.

A removable color-coordinated silicone base is included (not standard with all water bottles) that will protect the bottle from bumps and dents and help keep it in place when sat in cup holders or on treadmill trays.

The bottle's lid is also insulated meaning moisture won't collect around the narrow drinking spout and a great addition is a lid hinge lock which prevents it from flapping back and hitting you on the nose when drinking. Unscrew the lid and the wide mouth allows for easy cleaning or adding ice. You don't need to hand wash this bottle either as it's suitable for cleaning on the top rack of the dishwasher

If 18oz capacity isn't large enough, there are other sizes to suit your hydration needs, including 24oz, 32oz, 40oz and 64oz.

Best water bottle for walkers

The popular Hydro Flask Standard Mouth is the ideal companion when heading out on hikes and this larger-sized bottle will keep you hydrated during the day with water that stays ice cold for up to 24 hours.

The bottle is made from durable 18/8 stainless steel with a powder-coated outer that resists condensation, meaning the sides of the bottle will stay dry to touch. Honeycomb insulation controls the temperature of the BPA-free lid, meaning this will remain cool, too.

The bottle comes with a standard Flex Cap that you unscrew to drink, but if you don't enjoy swigging from a water bottle's mouth, you can buy Hydro Flask's Sip Lid or Straw Lid Cap which enables you to hydrate one-handed. What's more, you can build a bespoke bottle by choosing different coloured parts and customising it with text and graphics.

Best water bottle for cyclists

If you're a keen cyclist this may be the option for you.

The beauty of the Camelbak Podium Chill Water Bottle is that it's designed to fit in most bike bottle cages preventing rattles or ejections when out riding. It will also keep your drink cooler than other bike bottles thanks to its double-walled construction.

The flow spout is comfortable in the mouth, although you will need to squeeze both sides of the bottle to get the fluid out. When we just tried to suck, it was quite tricky. The self-sealing design of the valve prevents leaks or spills even without locking the nozzle – we shook the bottle for 30 seconds and didn't detect any spillage. However, there isn't a protective cap to protect against dirt or dust collecting around the mouthpiece but you can purchase a mud cap as an add-on if needed. Another draw is that the bottle can't hold a great amount of liquid, so, if like our tester, you're someone who tends to get quite thirsty, you might want to invest in a larger bottle.

The Camelbak Podium Chill comes apart for easy cleaning and it's fine to put this bottle in the dishwasher, provided it isn't at the highest temperature setting.

Best water bottle for purity

Reusable bottles rely on us filling them with tap water.

However, this may not always taste to your liking, but with the easy-to-carry Brita Active Water Filter Bottle you can have fresh, pure-tasting water on the move thanks to its built-in filtration system.

The bottle has a replaceable carbon filter microdisk that removes chlorine and impurities from water while retaining calcium and magnesium so that you still get the health benefits of these minerals. One disk comes in the box and depending on your daily water consumption, it should last you around four weeks before it needs replacing.

There's a cap that protects the mouthpiece from dirt, although it's worth noting that this is fully detachable so there's a risk of it getting lost. The easy-grip bottle comes apart and can be put in the dishwasher, making it simple to clean after use.

We found that the Brita Active Water Filter Bottle cap can be stored on the bottom of the bottle when needed and can also be used as a cup, which makes it handy if you have kids or even pets that might need a drink on the go.

Best water bottle for adding flavors

If you don't like drinking plain tap water, the Welly Traveler Infusing Water Bottle will appeal.

Made from 18/8 stainless steel, natural bamboo, silicone and BPA-free plastic, this option also includes a removable infuser so you can naturally flavor water with fruit or herbs.

Drinks are kept cool for up to 24 hours thanks to triple-walled vacuum insulation and the bottle's sweat-free exterior stops it from slipping out of your hands. A loop cap that unscrews comes as standard or there's the option to buy an insulated flip cap if that's your preferred lid for drinking.

There's an aesthetically-pleasing range of bottle designs to choose from including terrazzo and leopard print and it's also available in 12 oz and 28 oz sizes. Plus, your purchase will support a good cause with Welly donating 1% of bottle sales to clean water projects around the world.

Best large water bottle

If you're looking for a durable plastic bottle to use every day, the Camelbak Eddy+ is a great value option.

It's made from 50% recycled material that fights against odors and stains which are common bugbears when using a plastic bottle, plus there are six colors to choose from.

The Eddy+ holds 32oz of water that's delivered through a drink straw that you flip up and bite to release liquid. The straw's value is designed to prevent leaks when closed and spills when open but does need a strong bite to get a satisfying drink.

The only downside of this larger-sized bottle is that it's too big to fit in standard cup holders. If this is a dealbreaker, you may want to go for one the smaller sizes in Camelbak's range of Eddy bottles.

We found that for longer hikes, the Camelbak Eddy is a great size to keep you hydrated and can fit easily into a stretchy backpack bottle holder. The bite-to-drink feature is also useful when on the go, as it saves losing water to leaks.

Best stainless steel water bottle

S'well is the 'original' stainless steel bottle and this non-toxic, non-leaching and BPA free reusable is a bestseller for good reason.

With a stylish design (that's been frequently copied) it's available in an array of eye-catching colours and prints and three standard sizes of 9 oz, 17 oz and 25 oz. But that's not all. The S’well bottle boasts tripled-layered vacuum-insulating technology with this largest size keeping your drink cold for an impressive 48 hours, all while remaining moisture-free on the exterior.

It comes with a standard screw cap meaning you have to stop to take a sip, but the wide mouth is comfortable to drink from and also large enough to drop in ice cubes. To customise your bottle there's the option to buy accessories such as a sports cap for one-handed drinking, or a soft silicone handle for a more comfortable carry.

The one downside of this popular pick is that it isn't suitable for the dishwasher, but you may be willing to overlook the hassle of hand washing this for a high-performing bottle that doubles up as an attractive accessory too.

Best water bottle for durability

The Klean Kanteen Classic is a popular water bottle choice.

This is mainly because it can withstand the demands of an active lifestyle as well as being lightweight even when full.

The chip-resistant coating protects against bumps and bashes, so is great for outdoor activities and although this bottle isn't insulated, ice can be added to the 1.75 inch opening by unscrewing the lid. A narrow profile means it fits in most cup holders in cars and on exercise machines and strollers.

There are 10 colors/designs and four sizes in total to choose from and it comes with a sports cap with flow mouthpiece that can be removed for easy cleaning. Other compatible caps available to buy include a carry loop cap and a sippy cup cap for kids.

Best water bottle for portability

​​The Thermos Intak Bottle – also known as the Thermos Hydration Bottle, is a great value option for the gym or your commute to work and can be tossed in a bag without the worry of spillages.

The leak-proof lid opens with the press of a button and for peace of mind there's the addition of a locking ring mechanism to prevent it popping off in a bag. A narrow spout means drinking from it while walking isn't a problem and the whole lid screws off so you can easily add ice or fruit to your water.

If you need prompting to drink more water, there are handy volume markings on the side of the bottle and the lid has a dial tracker so you can monitor your intake. Although there's a good range of colors to choose from, a possible downside is that this water bottle only comes in one size. However, most people will find that the 24 oz capacity is more than enough to stay hydrated on-the-go until the next refill.

Best large-capacity water bottle

If you have serious hydration goals, the Aquafit 1 Gallon Water Bottle is the bottle to help you reach them.

This large capacity vessel holds 128 oz of liquid so that you don't have to worry about refills and there's also a time marker on the side to track how much you drink and ensure hydration levels are topped up from morning 'til night.

Two lids are included, a spout lid and a straw lid, along with a carry strap. A large handle makes it easier to lift when drinking, however, this bottle is obviously very large, so we didn't find it the most convenient option for taking to the office, since it took up most of our bag! For home working, however, it was a life saver and meant we didn't have to keep getting up from our desk to refill our glass.

There are eight colors to choose from and each water bottle comes with a brush for cleaning as this bottle isn't dishwasher-friendly.

Best water bottle for purification

Dubbed ‘the world’s first self cleaning bottle’, the LARQ PureVis has a rechargeable LED in its lid that uses UV-C light to sterilize itself and kill bacteria and odor-causing germs. To activate, just press the button on the top of the list to blitz 99.99 percent of pollutants and bio-contaminants in the water, including E. coli. The bottle also self cleans every two hours.

Let’s be honest, anything that requires less cleaning is a win from me, so I’m very happy with this bottle. LARQ still recommends you give it a wash occasionally but it’s good not to have to worry about that so much.

You don’t even need to charge it that much – once a month should do it – and you can enjoy fresh tasting water without that nasty musty smell bottles that tend to develop over time. It’s more expensive than regular reusable water bottles, but if clean water is important to you, then it’s a good investment (and think of the money you’re saving on purification filters). It’s also undoubtedly the most stylish water bottle on the market today.

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Water bottles: Frequently Asked Questions

The effects of global warming can be seen and felt across the planet. Global warming, the gradual heating of Earth's surface, oceans and atmosphere, is caused by human activity, primarily the burning of fossil fuels that pump carbon dioxide (CO2), methane and other greenhouse gases into the atmosphere.

Already, the consequences of global warming are measurable and visible.

"We can observe this happening in real time in many places," Josef Werne, a professor of geology and environmental science at the University of Pittsburgh, told Live Science. "Ice is melting in both polar ice caps and mountain glaciers. Lakes around the world, including Lake Superior, are warming rapidly — in some cases faster than the surrounding environment. Animals are changing migration patterns and plants are changing the dates of activity," such as trees budding their leaves earlier in the spring and dropping them later in the fall.

Here is an in-depth look at the ongoing effects of global warming.

Global warming increases average temperatures and temperature extremes

One of the most immediate and obvious consequences of global warming is the increase in temperatures around the world. The average global temperature has increased by about 1.4 degrees Fahrenheit (0.8 degrees Celsius) over the past 100 years, according to the National Oceanic and Atmospheric Administration (NOAA).

Since record keeping began in 1895, the hottest year on record worldwide was 2016, according to NOAA and NASA data. That year Earth's surface temperature was 1.78 degrees F (0.99 degrees C) warmer than the average across the entire 20th century. Before 2016, 2015 was the warmest year on record, globally. And before 2015? Yep, 2014. In fact, all 10 of the warmest years on record have occurred since 2005, which tied with 2013 as the 10th-warmest year on record, according to NOAA’s Global Climate Report 2021. Rounding out the top 6 hottest years on record across the globe are (in order of hottest to not as hot): 2020, 2019, 2015, 2017 and 2021.

For the contiguous United States and Alaska, 2016 was the second-warmest year on record and the 20th consecutive year that the annual average surface temperature exceeded the 122-year average since record keeping began, according to NOAA. Shattered heat records in the U.S. are increasingly becoming the norm: June 2021, for example, saw the warmest temperatures on record for that month for 15.2%of the contiguous U.S. That's the largest extent of record warm temperatures ever recorded in the country, according to the National Centers for Environmental Information.

Global warming increases extreme weather events

As global average temperatures warm, weather patterns are changing. An immediate consequence of global warming is extreme weather. 

These extremes come in a lot of different flavors. Paradoxically, one effect of climate change can be colder-than-normal winters in some areas.

Changes in climate can cause the polar jet stream — the boundary between the cold North Pole air and the warm equatorial air — to migrate south, bringing with it cold, Arctic air. This is why some states can have a sudden cold snap or colder-than-normal winter, even during the long-term trend of global warming, Werne explained.

"Climate is, by definition, the long-term average of weather, over many years. One cold (or warm) year or season has little to do with overall climate. It is when those cold (or warm) years become more and more regular that we start to recognize it as a change in climate rather than simply an anomalous year of weather," he said.

Global warming is also changing other extreme weather. According to the Geophysical Fluid Dynamics Laboratory of NOAA, hurricanes are likely to become more intense, on average, in a warming world. Most computer models suggest that hurricane frequency will stay about the same (or even decrease), but those storms that do form will have the capacity to drop more rain due to the fact that warmer air holds more moisture.

"And even if they become less frequent globally, hurricanes could still become more frequent in some particular areas," said atmospheric scientist Adam Sobel, author of "Storm Surge: Hurricane Sandy, Our Changing Climate, and Extreme Weather of the Past and Future" (HarperWave, 2014). "Additionally, scientists are confident that hurricanes will become more intense due to climate change." This is because hurricanes get their energy from the temperature difference between the warm tropical ocean and the cold upper atmosphere. Global warming increases that temperature difference.

"Since the most damage by far comes from the most intense hurricanes — such as typhoon Haiyan in the Philippines in 2013 — this means that hurricanes could become overall more destructive," said Sobel, a Columbia University professor in the departments of Earth and Environmental Sciences, and Applied Physics and Applied Mathematics. (Hurricanes are called typhoons in the western North Pacific, and they're called cyclones in the South Pacific and Indian oceans.)

What's more, hurricanes of the future will be hitting shorelines that are already prone to flooding due to the sea-level rise caused by climate change. This means that any given storm will likely cause more damage than it would have in a world without global warming.

Lightning is another weather feature that is being affected by global warming. According to a 2014 study, a 50% increase in the number of lightning strikes within the United States is expected by 2100 if global temperatures continue to rise. The researchers of the study found a 12% increase in lightning activity for every 1.8 degree F (1 degree C) of warming in the atmosphere. NOAA established the U.S. Climate Extremes Index (CEI) in 1996 to track extreme weather events. The number of extreme weather events that are among the most unusual in the historical record, according to the CEI, has been rising over the last four decades. Scientists project that extreme weather events, such as heat waves, droughts, blizzards and rainstorms will continue to occur more often and with greater intensity due to global warming, according to Climate Central. Climate models forecast that global warming will cause climate patterns worldwide to experience significant changes. These changes will likely include major shifts in wind patterns, annual precipitation and seasonal temperatures variations. These impacts vary by location and geography. For example, according to the U.S. Environmental Protection Agency (EPA), the eastern United States has been trending wetter over time, while the West – and particularly the Southwest – have become increasingly dry. Because high levels of greenhouse gases are likely to remain in the atmosphere for many years, these changes are expected to last for several decades or longer, according to the EPA.

Global warming melts ice

One of the primary manifestations of climate change so far is melt. North America, Europe and Asia have all seen a trend toward less snow cover between 1960 and 2015, according to 2016 research published in the journal Current Climate Change Reports. According to the National Snow and Ice Data Center, there is now 10% less permafrost, or permanently frozen ground, in the Northern Hemisphere than there was in the early 1900s. The thawing of permafrost can cause landslides and other sudden land collapses. It can also release long-buried microbes, as in a 2016 case when a cache of buried reindeer carcasses thawed and caused an outbreak of anthrax.

One of the most dramatic effects of global warming is the reduction in Arctic sea ice. Sea ice hit record-low extents in both the fall and winter of 2015 and 2016, meaning that at the time when the ice is supposed to be at its peak, it was lagging. The melt means there is less thick sea ice that persists for multiple years. That means less heat is reflected back into the atmosphere by the shiny surface of the ice and more is absorbed by the comparatively darker ocean, creating a feedback loop that causes even more melt, according to NASA's Operation IceBridge.

Glacial retreat, too, is an obvious effect of global warming. Only 25 glaciers bigger than 25 acres are now found in Montana's Glacier National Park, where about 150 glaciers were once found, according to the U.S. Geological Survey. A similar trend is seen in glacial areas worldwide. According to a 2016 study in the journal Nature Geoscience, there is a 99% likelihood that this rapid retreat is due to human-caused climate change. Some glaciers retreated up to 15 times as much as they would have without global warming, those researchers found.

Sea levels and ocean acidification

In general, as ice melts, sea levels rise. According to a 2021 report by the World Meteorological Organization, the pace of sea level rise doubled from 0.08 inches (2.1 millimeters) per year between 1993 and 2002 to 0.17 inches (4.4 mm) per year between 2013 and 2021. 

Melting polar ice in the Arctic and Antarctic regions, coupled with melting ice sheets and glaciers across Greenland, North America, South America, Europe and Asia, are expected to raise sea levels significantly. Global sea levels have risen about 8 inches since 1870, according to the EPA, and the rate of increase is expected to accelerate in the coming years. If current trends continue, many coastal areas, where roughly half of the Earth's human population lives, will be inundated.

Researchers project that by 2100, average sea levels will be 2.3 feet (.7 meters) higher in New York City, 2.9 feet (0.88 m) higher at Hampton Roads, Virginia, and 3.5 feet (1.06 m) higher at Galveston, Texas, the EPA reports. According to an IPCC report, if greenhouse gas emissions remain unchecked, global sea levels could rise by as much as 3 feet (0.9 meters) by 2100. That estimate is an increase from the estimated 0.9 to 2.7 feet (0.3 to 0.8 meters) that was predicted in the 2007 IPCC report for future sea-level rise.

Sea level isn't the only thing changing for the oceans due to global warming. As levels of CO2 increase, the oceans absorb some of that gas, which increases the acidity of seawater. Werne explains it this way: "When you dissolved CO2 in water, you get carbonic acid. This is the same exact thing that happens in cans of soda. When you pop the top on a can of Dr Pepper, the pH is 2 — quite acidic."  

Since the Industrial Revolution began in the early 1700s, the acidity of the oceans has increased about 25 percent, according to the EPA. "This is a problem in the oceans, in large part, because many marine organisms make shells out of calcium carbonate (think corals, oysters), and their shells dissolve in acid solution," said Werne. "So as we add more and more CO2 to the ocean, it gets more and more acidic, dissolving more and more shells of sea creatures. It goes without saying that this is not good for their health."

If current ocean acidification trends continue, coral reefs are expected to become increasingly rare in areas where they are now common, including most U.S. waters, the EPA reports. In 2016 and 2017, portions of the Great Barrier Reef in Australia were hit with bleaching, a phenomenon in which coral eject their symbiotic algae. Bleaching is a sign of stress from too-warm waters, unbalanced pH or pollution; coral can recover from bleaching, but back-to-back episodes make recovery less likely.

Plants and animals

The effects of global warming on Earth's ecosystems are expected to be significant and widespread. Many species of plants and animals are already moving their range northward or to higher altitudes as a result of warming temperatures, according to a report from the National Academy of Sciences.

"They are not just moving north, they are moving from the equator toward the poles. They are quite simply following the range of comfortable temperatures, which is migrating to the poles as the global average temperature warms," Werne said. Ultimately, he said, this becomes a problem when the rate of climate change velocity (how fast a region changes put into a spatial term) is faster than the rate that many organisms can migrate. Because of this, many animals may not be able to compete in the new climate regime and may go extinct.

Additionally, migratory birds and insects are now arriving in their summer feeding and nesting grounds several days or weeks earlier than they did in the 20th century, according to the EPA.

Warmer temperatures will also expand the range of many disease-causing pathogens that were once confined to tropical and subtropical areas, killing off plant and animal species that formerly were protected from disease.

In addition, animals that live in the polar regions are facing an existential threat. In the Arctic, the decline in sea ice and changes in ice melt threaten particularly ice-dependent species, such as narwhals (Monodon monoceros), polar bears (Ursus maritimus) and walruses (Odobenus rosmarus), the World Wildlife Fund (WWF) noted. Animals in the Antarctic also face serious challenges — in Oct. 2022 the U.S. Fish and Wildlife Service declared emperor penguins (Aptenodytes forsteri) as endangered due to the threat of climate change. 

A 2020 study published in the journal Proceedings of the National Academy of Sciences suggested that 1 in every 3 species of plant and animal are at risk of extinction by 2070 due to climate change.

Social effects

As dramatic as the effects of climate change are expected to be on the natural world, the projected changes to human society may be even more devastating.

Agricultural systems will likely be dealt a crippling blow. Though growing seasons in some areas will expand, the combined impacts of drought, severe weather, lack of accumulated snowmelt, greater number and diversity of pests, lower groundwater tables and a loss of arable land could cause severe crop failures and livestock shortages worldwide.

North Carolina State University also notes that carbon dioxide is affecting plant growth. Though CO2 can increase the growth of plants, the plants may become less nutritious.

This loss of food security may, in turn, create havoc in international food markets and could spark famines, food riots, political instability and civil unrest worldwide, according to a number of analyses from sources as diverse as the U.S Department of Defense, the Center for American Progress and the Woodrow Wilson International Center for Scholars.

In addition to less nutritious food, the effect of global warming on human health is also expected to be serious. The American Medical Association has reported an increase in mosquito-borne diseases like malaria and dengue fever, as well as a rise in cases of chronic conditions like asthma, most likely as a direct result of global warming. The 2016 outbreak of Zika virus, a mosquito-borne illness, highlighted the dangers of climate change. The disease causes devastating birth defects in fetuses when pregnant women are infected, and climate change could make higher-latitude areas habitable for the mosquitoes that spread the disease, experts said. Longer, hotter summers could also lead to the spread of tick-borne illnesses.

Further reading on the impacts of global warming

Many governments and agencies keep up-to-date information on climate change research and statistics online. The most comprehensive and in-depth global reports are produced by the Intergovernmental Panel on Climate Change (IPCC), which released its Sixth Assessment Report on the science of climate change in 2021.

For a historical look at the effects of climate change on Earth (and how modern warming compares), read Peter Brannen's "The Ends of the Earth: Volcanic Apocalypses, Lethal Oceans, and Our Quest to Understand Earth’s Past Mass Extinctions" (Ecco, 2017).

For more on the potential impacts of climate change in urban environments, the freely available book chapter Climate Change and its Impacts in the book "Climate Change Resilience in the Urban Environment" (IOP Publishing, 2017) covers the challenges that lay ahead for human populations.

Finally, for a psychological deep-dive on why all of this bad news is hard to take in, try "Don't Even Think About It: Why Our Brains Are Wired to Ignore Climate Change" (Bloomsbury USA, 2015) by climate activist and communicator George Marshall.

Additional resources

• This NASA page includes a series of visualizations that illustrate how some of Earth's key climate indicators —  sea ice, sea level, global temperature and carbon dioxide — are changing over time.
• This NOAA sea-level rise learning module includes educational videos, background for teachers, learning objectives and more.
• ClimateBrief has gathered 10 of the best climate change videos on YouTube. 

Bibliography

• EPA: Climate Change: Basic Information 
• NASA: Global Climate Change
• NOAA: Climate News and Data

A  trio of technicolor lakes in Ethiopia, each one a different color from the others, is visible in stunning detail in a satellite image recently released by NASA. The unusual colors are the result of numerous factors, including water chemistry, depth and inhabiting wildlife.

The three lakes are Lake Shala, which has a deep blue hue; Lake Abijatta, which is green in color; and Lake Langano, which has a sandy-yellow hue similar to the surrounding land. The lakes are located in Ethiopia's Great Rift Valley, around 124 miles (200 kilometers) south of the capital, Addis Ababa. 

The Landsat 8 satellite, which is co-owned by NASA and the U.S. Geological Survey, snapped the striking real-color image months ago using the onboard Operational Land Imager. The image was released online Oct. 7 by NASA's Earth Observatory.

Related: Landsat satellites: 12 amazing images of Earth from space 

Lake Shala, which is around 7.5 miles (12 km) long and 17.4 miles (28 km) across at its widest point, is the deepest of the three lakes, with a maximum depth of 873 feet (266 meters), which makes the water appear a deep blue color from above. The lake has numerous vents on its bottom that pump sulfur into the water. As a result, the lake is highly alkaline, meaning it has a very high pH. Despite the extreme conditions, the lake contains a large number of small crustaceans and microorganisms that support large flocks of visiting flamingos and pelicans, according to Earth Observatory. 

Lake Abijatta, which is around 10.6 miles (17 km) long and 9.3 miles (15 km) wide, is the shallowest of the three lakes, with a maximum depth of 46 feet (14 m). As a result, Abijatta is the most variable of the pictured lakes; within the last 50 years, the lake has lost around one-third of its area, according to Earth Observatory. Lake Abijatta's green color is most likely due to a bloom of phytoplankton on its surface.

Lake Langano, which is around 11.2 miles (18 km) long and 9.9 miles (16 km) across, is fed mostly by streams to the east. The lake's yellow color comes from brown sediment that is transported from nearby mountains by the rivers that feed it. Langano is a popular destination for beachgoers because it is the only lake in the region not inhabited by parasitic worms that transmit a potentially fatal disease known as schistosomiasis, according to Earth Observatory.

The contrasting appearance of the lakes is even more surprising considering that all three used to be part of a single ancient body of water known as Lake Galla, which also included the nearby Lake Ziway. The enormous ancient lake was likely connected to the sea via the Awash River (which still flows today) up until around 10,000 years ago. At that point, tectonic plate movements and changes in rainfall patterns caused Lake Galla to begin to dry up. By around 2,000 years ago, the lake had fractured into the different lakes visible today, according to Earth Observatory. 

Biology is the study of life. The word "biology" is derived from the Greek words "bios" (meaning life) and "logos" (meaning "study"). In general, biologists study the structure, function, growth, origin, evolution and distribution of living organisms.

Biology is important because it helps us understand how living things work and how they function and interact on multiple levels, according to the Encyclopedia Britannica. Advances in biology have helped scientists do things such as develop better medicines and treatments for diseases, understand how a changing environment might affect plants and animals, produce enough food for a growing human population and predict how eating new food or sticking to an exercise regimen might affect our bodies.

The basic principles of modern biology

Four principles unify modern biology, according to the book "Managing Science" (Springer New York, 2010): 

1. Cell theory is the principle that all living things are made of fundamental units called cells, and all cells come from preexisting cells.
2. Gene theory is the principle that all living things have DNA, molecules that code the structures and functions of cells and get passed to offspring.
3. Homeostasis is the principle that all living things maintain a state of balance that enables organisms to survive in their environment.
4. Evolution is the principle that describes how all living things can change to have traits that enable them to survive better in their environments. These traits result from random mutations in the organism's genes that are "selected" via a process called natural selection. During natural selection, organisms that have traits better-suited for their environment have higher rates of survival, and then pass those traits to their offspring.

The many branches of biology

Although there are only four unifying principles, biology covers a broad range of topics that are broken into many disciplines and subdisciplines.

On a high level, the different fields of biology can each be thought of as the study of one type of organism, according to "Blackie's Dictionary of Biology" (S Chand, 2014). For example, zoology is the study of animals, botany is the study of plants and microbiology is the study of microorganisms.

Within those broader fields, many biologists specialize in researching a specific topic or problem. For example, a scientist may study behavior of a certain fish species, while another scientist may research the neurological and chemical mechanisms behind the behavior.

There are numerous branches and subdisciplines of biology, but here is a short list of some of the more broad fields that fall under the umbrella of biology: 

Biochemistry: The study of the chemical processes that take place in or are related to living things, according to the Biochemical Society. For example, pharmacology is a type of biochemistry research that focuses on studying how drugs interact with chemicals in the body, as described in a 2010 review in the journal Biochemistry. 

Ecology: The study of how organisms interact with their environment. For example, an ecologist may study how honeybee behavior is affected by humans living nearby. 

Genetics: The study of heredity. Geneticists study how genes are passed down by parents to their offspring, and how they vary from person to person. For example, scientists have identified several genes and genetic mutations that influence human lifespan, as reported in a 2019 review published in the journal Nature Reviews Genetics.   

Physiology: The study of how living things work. Physiology, which is applicable to any living organism, "deals with the life-supporting functions and processes of living organisms or their parts," according to Nature. Physiologists seek to understand biological processes, such as how a particular organ works, what its function is and how it's affected by outside stimuli. For example, physiologists have studied how listening to music can cause physical changes in the human body, such as a slower or faster heart rate, according to the journal Psychological Health Effects of Musical Experiences. . 

The multidisciplinary nature of biology

Biology is often researched in conjunction with other fields of study, including mathematics, engineering and the social sciences. Here are a few examples:

Astrobiology is the study of the evolution of life in the universe, including the search for extraterrestrial life, according to NASA. This field incorporates principles of biology with astronomy. 

Bioarchaeologists are biologists who incorporate archaeological techniques to study skeletal remains and derive insights about how people lived in the past, according to George Mason University.

Bioengineering is the application of engineering principles to biology and vice versa, according to the University of California Berkeley. For example, a bioengineer might develop a new medical technology that better images the inside of the body, like an improved Magnetic Resonance Imaging (MRI) that scans the human body at a faster rate and higher resolution, or apply biological knowledge to create artificial organs, according to the journal Cell Transplant.

Biotechnology involves using biological systems to develop products, according to the Norwegian University of Science and Technology. For example, biotechnologists in Russia genetically engineered a better-tasting and more disease-resistant strawberry, which the researchers described in their 2007 study published in the journal Biotechnology and Sustainable Agriculture 2006 and Beyond.  

Biophysics employs the principles of physics to understand how biological systems work, according to the Biophysical Society. For example, biophysicists may study how genetic mutations leading to changes in protein structure impacts protein evolution, according to the Journal of the Royal Society

What do biologists do?

Biologists can work in many different fields, including research, healthcare, environmental conservation and art, according to the American Institute of Biological Sciences. Here are a few examples:

Research: Biologists can perform research in many types of settings. Microbiologists, for instance, may study bacterial cultures in a laboratory setting. Other biologists may perform field research, where they observe animals or plants in their native habitat. Many biologists may work in the lab and in the field — for example, scientists may collect soil or water samples from the field and analyze them further in the  lab, like at North Carolina University's Soil and Water Lab.

Conservation: Biologists can help with efforts in environmental conservation by studying and determining how to protect and conserve the natural world for the future. For example, biologists may help educate the public on the importance of preserving an animal's natural habitat and participate in endangered species recovery programs to stop the decline of an endangered species, according to the U.S. Fish & Wildlife Service.

Healthcare: People who study biology can go on to work in healthcare, whether they work as doctors or nurses, join a pharmaceutical company to develop new drugs and vaccines, research the efficacy of medical treatments or become veterinarians to help treat sick animals, according to the American Institute of Biological Sciences.

Art: Biologists who also have a background in art have both the technical knowledge and artistic skill to create visuals that will communicate complex biological information to a wide variety of audiences. One example of this is in medical illustration, in which an illustrator may perform background research, collaborate with experts, and observe a medical procedure to create an accurate visual of a body part, according to the Association of Medical Illustrators.

Additional resources

If you’re curious about just how wide-reaching biology is, The University of North Carolina at Pembroke has listed a number of biology subdisciplines on their website. Interested in a career in biology? Check out some options at the American Institute of Biological Sciences website.

Bibliography

Lornande Loss Woodruff, “History of Biology”, The Scientific Monthly, Volume 12, March 1921, http://www.jstor.org/stable/6836.  

P.N. Campbell, “Biology in Profile: A Guide to the Many Branches of Biology”, Elsevier, October 2013. 

The University of North Carolina at Pembroke, “Biology Sub-disciplines”, October 2010. 

University of Minnesota Duluth, “What is Biology?”, January 2022. 

Eric J. Simon et al, “Campbell Essential Biology”, Pearson Education, January 2018. 

The meaning of colors are often imbued with great symbolic power. Even in the modern English-speaking world, where superstitious beliefs have largely faded in the light of scientific knowledge, many colors have retained their ancient associations.

Most people know that brides often wear white, that "seeing red" means being angry, and that one can feel "green with envy." But learning why these connotations exist requires a look back to the beliefs and practices of the ancients.

Red

Red has a range of symbolic meanings through many different cultures, including life, health, vigor, war, courage, anger, love and religious fervor. The common thread is that all these require passion.

In moments of rage, lust or embarrassment, bright red oxygenated blood rushes to the skin's surface as a response to your “fight or flight” sympathetic nervous system. There are many theories as to why human and non-human species have evolved this physiological trait, however many center their conclusions around asserting dominance or appearing more attractive to a potential mate, according to the journal Philosophical Transactions of the Royal Society B.

In relation to dominance, the colour red has even been found to impact the world of sport. A study published in the journal Nature found that several soccer teams achieved greater match results while wearing predominantly red shirts than while playing in other colours, such as white and blue. 

Colors were so powerful in traditional cultures that red objects were believed to convey health through their color alone. For example, most red stones such as garnets and rubies were believed to have health-giving and disease-preventing properties. In Rome, children wore red coral as a talisman to protect them from diseases, and in China, for similar reasons, children always wore a piece of red clothing.

White

Throughout history, white has been synonymous with purity and virtue, which lends itself to many religious ceremonies. For example, wearing white to a wedding dates back more than 2,000 years when Roman brides wore white tunics to signal a woman’s virginity, according to Ohio State University. 

However, it wasn’t until Queen Victoria walked down the aisle in a white lace dress to wed Prince Albert in 1840, that wearing white wedding gown became popular. In many Asian cultures, particularly in China, white is not a traditional used for wedding gowns – red or gold may be more commonly seen wedding colors – but is worn instead of black at funeral services and is a symbol of mourning, according to Yerevan State University.

Although white is often referred to as a “color”, white is actually the combination of all the wavelengths of color that are reflected off an object, according to Encyclopedia Britannica. 

Black

The colour – or rather adsense of colour– black is often linked with negative associations, such as death, fear or sadness, according to the Journal of international Colour Association. 

Many ancient cultures believed that black was "the color of mystery and of the mysterious ways and wisdom of God,"  historian Ellen Conroy wrote in her book "The Symbolism of Colors" (1921). This was because night, the absence of light, transcended human perception in the same way that the wisdom of God was thought to be beyond comprehension.

Of all mysteries, death may have been the biggest. Ancient people were completely "in the dark" about what would happen to them after death, and so it was (and is) represented by the color black in many cultures. There was the added coincidence of death sharing similarities with sleep, which happens in the darkness of night and when closed eyelids block out all light. Throughout history the color black has also been attached to fearful and mysterious things, such as black magic, black holes, the black plague and so on. 

Of course the black isn’t always synonymous with death and despair, especially in the world of fashion. A study published in the journal Color Research and Application found that black was the overall favourite color to wear amongst female study participants. 

Purple

Purple symbolizes royalty, nobility and imperialism. In many European societies, the symbolism was even established by law: From ancient Rome to Elizabethan England, "sumptuary laws" forbade anyone except close members of the royal family to wear the color, according to Harvard Law School.

Purple's elite status stems from the rarity and cost of the dye originally used to produce it. Fabric traders obtained "Tyrian purple," as the dye was called, from a small mollusk that was found only in a region of the Mediterranean Sea near Tyre, a Phoenician trading city located in modern-day Lebanon, according to the journal Molecules. More than 9,000 mollusks were needed to create just one gram of Tyrian purple, and because only wealthy rulers could afford to buy and wear fabrics dyed with the color, it became associated with the imperial classes of Rome, Egypt and Persia. 

Another consequence of this is that purple also came to represent spirituality and holiness, because the ancient emperors, kings and queens that wore the color were often considered to be gods or descendants of the gods.

Blue

According to Conroy, the primary association of the color blue for most of recorded history was with truth a meaning that leaves a remnant in our language in the phrase "true blue." This was because blue is the color of a calm and clear sky, and it is in calm reflection that leads to truth.

Today, though, blue mainly conveys sadness and despair. When you've "got the blues," you're down in the dumps. The connotation may relate to tears and rain , as water was typically represented in people's minds as blue. 

However, research has shown that the colour blue has many positive effects on people. For example, research exploring crime on the streets of both Glasgow, Scotland, and Nara, Japan, found that crime levels decreased in areas where blue streetlights had been installed, according to Psychology Today.

Green

For obvious reasons, the color green represents nature and the environment; more abstractly, it symbolizes wisdom. The latter association has ancient roots.

According to Conroy, the Egyptians believed that a god named Thoth led the souls of the dead to "a green hill of everlasting life and eternal wisdom." Later, the Romans based their god Mercury on Thoth, and the planet Mercury was in turn based on the god. For this reason, in astrology,"green is sometimes said to be the color of the planet Mercury, which is the planet governing the mind and conferring knowledge knowledge not only of the kind essential to material success, but also inspirational knowledge and celestial wisdom," Conroy wrote.

Aside from its association with wisdom, there's a flipside to green. "Green in its degraded sense gives us 'the green-eyed monster jealousy,' which is the direct opposite of celestial wisdom, for jealousy is always due to the intrusion of the desires of the self, while celestial wisdom wishes to give rather than to receive," Conroy wrote.

The color green has also been firmly attributed to the environment – in particular when used to illustrate products or campaigns which support the health of the planet. According to the BBC the word “green” comes from the Proto-Indo-European (ancient people that lived around the 4th millenium BC) word “ghre”, which means “grow”. It is fair to assume that green’s connection to nature lies in its abundance amongst it. The majority of plant’s naturally produce green-colored pigments called chlorophyll which are the sites for the conversion of atmospheric carbon dioxide into breathable oxygen, known as photosynthesis.

Yellow

It isn't surprising that yellow symbolizes happiness, warmth and sunshine in most cultures; these are characteristics of the yellow sun and its effects.

In ancient cultures where a god or gods were associated with the sun, such as Egypt and China, yellow was the highest and noblest of colors and thus, the color of religious figures and royals (who were thought to be descendants of the gods).

Conroy explains that all colors have a flipside, a degraded meaning that traditionally opposed the positive one. Along with warmth and happiness,  yellow also represents cowardliness and deceit. "We recognize the deceitful Judas very often in ancient pictures from the fact that he is given dingy yellow robes," she wrote.

Orange

Similarly to red, orange has a range of symbolic meaning and connotations – for example – in many Western cultures orange is often used for fun, strength, courage and creativity, according to the Huffington Post. 

In recent history, though, orange has come to denote a warning, and is used for high visibility clothing (such as spacesuits ) and safety equipment (such as traffic cones). This association is a practical one: Orange contrasts most strongly with the color blue and therefore is highly visible against a clear sky.

Additional resources

For more information about how colors have impacted the world throughout history, check out “The Colors of History: How Colors Shaped the World” by Clive Glifford and “Color: A Natural History of the Palette” by Victoria Finlay. 

Bibliography

Andrew Elliot, “Color and psychological functioning: a review of theoretical and empirical work”, Frontiers in Psychology, Volume 6, April 2015, https://doi.org/10.3389/fpsyg.2015.00368 

Naira Gasparyan, “Color symbolism and its cognitive cultural message”, Yerevan State University, 2019. 

Nina Jablonski and George Chaplin, “The colours of humanity: the evolution of pigmentation in the human lineage”, Philosophical Transcriptions of the Royal Society B, Volume 372, May 2017, https://doi.org/10.1098/rstb.2016.0349 

Behind the phenomena of global warming and climate change lies the increase in greenhouse gases in our atmosphere. A greenhouse gas is any gaseous compound in the atmosphere that is capable of absorbing infrared radiation, thereby trapping and holding heat in the atmosphere. By increasing the heat in the atmosphere, greenhouse gases are responsible for the greenhouse effect, which ultimately leads to global warming. (The effects of global warming can been seen across the globe.)

Related: 10 signs that Earth's climate is off the rails

Solar radiation and the "greenhouse effect"

Global warming isn't a recent scientific concept. The basics of the phenomenon were worked out well over a century ago by Swedish physicist and chemist Svante Arrhenius, in 1896. His paper, published in the Philosophical Magazine and Journal of Science, was the first to quantify the contribution of carbon dioxide to what scientists now call the "greenhouse effect."

The greenhouse effect occurs because the sun bombards Earth with enormous amounts of radiation that strike Earth's atmosphere in the form of visible light, plus ultraviolet (UV), infrared (IR) and other types of radiation that are invisible to the human eye. UV radiation has a shorter wavelength and a higher energy level than visible light, while IR radiation has a longer wavelength and a weaker energy level. About 30% of the radiation that strikes Earth is reflected back out to space by clouds, ice and other reflective surfaces. The remaining 70% is absorbed by the oceans, the land and the atmosphere, according to NASA's Earth Observatory.

As they heat up, the oceans, land and atmosphere release heat in the form of IR thermal radiation, which passes out of the atmosphere and into space. It's this equilibrium of incoming and outgoing radiation that makes the Earth habitable, with an average temperature of about 59 degrees Fahrenheit (15 degrees Celsius), according to NASA. Without this atmospheric equilibrium, Earth would be as cold and lifeless as its moon, or as blazing hot as Venus. The moon, which has almost no atmosphere, is about minus 243 F (minus 153 C) on its dark side. Venus, on the other hand, has a very dense atmosphere that traps solar radiation; the average temperature on Venus is about 864 F (462 C).

The exchange of incoming and outgoing radiation that warms the Earth is often referred to as the greenhouse effect because an agricultural greenhouse works in much the same way. Incoming shortwave UV radiation easily passes through the glass walls of a greenhouse and is absorbed by the plants and hard surfaces inside. Weaker, longwave IR radiation, however, has difficulty passing through the glass walls and is thereby trapped inside, warming the greenhouse.

How greenhouse gases cause global warming

The gases in the atmosphere that absorb radiation are known as "greenhouse gases" (abbreviated as GHG) because they are largely responsible for the greenhouse effect. The greenhouse effect, in turn, is one of the leading causes of global warming. The most significant greenhouse gases, according to the Environmental Protection Agency (EPA), are: water vapor (H2O), carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O). 

"While oxygen (O2) is the second most abundant gas in our atmosphere, O2 does not absorb thermal infrared radiation," Michael Daley, an associate professor of environmental science at Lasell College in Massachusetts, told Live Science.

Global warming and the greenhouse gases that cause it occur naturally — without them, Earth's average surface temperature would be a gelid zero degrees F (minus 18 C). But the amount of greenhouse gases in the atmosphere has skyrocketed to detrimental levels in recent history. 

Related: Carbon dioxide soars to record breaking levels not seen in at least 800,000 years

During the 20,000-year period before the Industrial Revolution, atmospheric CO2 fluctuated between about 180 parts per million (ppm) during ice ages and 280 ppm during interglacial warm periods. However, since the beginning of the Industrial Revolution in the 1750s, the amount of CO2 has risen nearly 50%, according to NASA’s Global Climate Change portal. Today, CO2 levels stand at over 410 ppm.

Fluorinated gases — gases to which the element fluorine has been added — are created during industrial processes and are also considered greenhouse gases. These include hydrofluorocarbons, perfluorocarbons and sulfur hexafluoride. Although they are present in the atmosphere in very small concentrations, they trap heat very effectively, making them high "global warming potential" (GWP) gases.

Chlorofluorocarbons (CFCs), once used as refrigerants and aerosol propellants until they were phased out by international agreement, are also greenhouse gases.

Related: Global warming vs. solar cooling: The showdown begins in 2020

There are three factors that affect the degree to which a greenhouse gas will influence global warming: Its abundance in the atmosphere, how long it stays in the atmosphere and its GWP. For example, water vapor is the most abundant greenhouse gas, but carbon dioxide has a more significant impact on global warming due to its abundance in the atmosphere plus its relatively long atmospheric lifetime of 300 to 1,000 years, according to NASA. Water vapor, on the other hand, has an atmospheric lifetime of no more than 10 days, according to a 2020 study published in the Journal of the Atmospheric Sciences.

Methane is about 21 times more efficient at absorbing radiation than CO2, giving it a higher GWP rating, even though it stays in the atmosphere for only about 12 years, according to the United Nations Framework Convention on Climate Change (UNFCCC). Although methane and other GHGs are capable of trapping more heat than CO2, scientists still consider carbon dioxide to be the dominant greenhouse gas because its warming effect outlives the others' effects by centuries.

Sources of greenhouse gases

Some greenhouse gases, such as methane, are produced through agricultural practices, in the form of livestock manure, for example. Others, like CO2, largely result from natural processes like respiration, and from the burning of fossil fuels like coal, oil and gas.

Another primary source of CO2 is deforestation. When trees are felled to produce goods or heat, they release the carbon that is normally stored for photosynthesis. This process releases up to 4.8 billion metric tons of carbon into the atmosphere every year, according to the World Resources Institute.

Forestry and other land-use practices can offset some of these greenhouse gas emissions. "Replanting helps to reduce the buildup of carbon dioxide in the atmosphere as growing trees sequester carbon dioxide through photosynthesis," Daley told Live Science. "However, forests cannot sequester all of the carbon dioxide we are emitting to the atmosphere through the burning of fossil fuels, and a reduction in fossil fuel emissions is still necessary to avoid buildup in the atmosphere."

Worldwide, the output of greenhouse gases is a source of grave concern. According to NOAA’s Climate.gov, over the past 60 years, atmospheric CO2 has increased at an annual rate that's 100 times faster than previous natural increases. The last time global atmospheric CO2 amounts were this high was 3 million years ago, when temperatures were up to 5.4 degrees F (3 degrees C) higher than during the pre-industrial era. As a result of modern-day CO2-induced global warming, 2016 was the warmest year on record, with 2019 and 2020 ranking as the next warmest, respectively. In fact, the six hottest years on record have all occurred since 2015, according to the World Meteorological Organization.

"The warming we observe affects atmospheric circulation, which impacts rainfall patterns globally," said Josef Werne, an associate professor in the Department of Geology and Planetary Science at the University of Pittsburgh. "This will lead to big environmental changes, and challenges, for people all across the globe."

Our planet's future

If current trends continue, scientists, government officials and a growing number of citizens fear that the worst effects of global warming — extreme weather, rising sea levels, plant and animal extinctions, ocean acidification, major shifts in climate and unprecedented social upheaval — will be inevitable.

In an effort to combat GHG-induced global warming, the U.S. government created a climate action plan in 2013. And in April 2016, representatives from 73 countries signed the Paris Agreement, an international pact to combat climate change by investing in a sustainable, low-carbon future, according to the UNFCCC. Although the U.S. withdrew from the Paris Agreement in 2017, it rejoined in late-January 2021. President Biden's administration has also set a target of reducing U.S. emissions by 50-52% of 2005 levels by the year 2030. (Emissions are routinely compared to those in 2005 — the year U.S. emissions of CO2 peaked at nearly 6 billion tons.)

In 2020, global carbon dioxide emissions fell 6.4% (13% in the U.S. alone) — the first time in decades the annual rate hasn’t climbed, Nature reported. This was in part due to the decrease in fossil fuel combustion resulting from the switch to natural gas from coal, but largely because of the forced standstill in economic, social and transportation activities in response to the COVID-19 pandemic. Scientists expected the annual emissions decline to actually be larger than it was, but emissions rebounded as restrictions were lifted in some nations and activities recovered toward the end of 2020. 

Related: Global carbon emissions dropped an unprecedented 17% during the coronavirus lockdown — and it changes nothing

In order to limit global warming to the 2.7 degree F (1.5 degree C) target set by the Paris Agreement, the world still needs to cut its CO2 emissions by 7.6% for the next decade, according to the UN Environment Programme. 

Researchers around the world continue to work toward finding ways to lower greenhouse gas emissions and mitigate their effects. One potential solution scientists are examining is to suck some of the carbon dioxide out of the atmosphere and bury it underground indefinitely. Advocates argue that carbon capture and storage is technologically feasible, but market forces have prevented widespread adoption. 

Whether or not removing already-emitted carbon from the atmosphere is feasible, preventing future warming requires stopping the emissions of greenhouse gases. The most ambitious effort to forestall warming thus far is the 2016 Paris Agreement. This nonbinding international treaty aims to keep warming "well below 2 degrees Celsius above pre-industrial levels and to pursue efforts to limit the temperature increase even further to 1.5 degrees Celsius," according to the United Nations. Each signatory to the treaty agreed to set their own voluntary greenhouse gas emission limits and to make them stricter over time. Climate scientists said that the emissions limits committed under the agreement wouldn't keep warming as low as 1.5 or even 2 degrees C, but that it would be an improvement over the "business-as-usual" scenario.

Additional resources

• Find out the latest research and policy updates regarding global warming via NOAA's Climate.gov portal.
• Learn more about the Global Carbon Project.
• Read more about the impact of COVID-19 on 2020 CO2 emissions, according to Carbon Brief.

Sometime between 11,000 and 5,000 years ago, after the last ice age ended, the Sahara Desert transformed. Green vegetation grew atop the sandy dunes and increased rainfall turned arid caverns into lakes. About 3.5 million square miles (9 million square kilometers) of Northern Africa turned green, drawing in animals such as hippos, antelopes, elephants and aurochs (wild ancestors of domesticated cattle), who feasted on its thriving grasses and shrubs. This lush paradise is long gone, but could it ever return? 

In short, the answer is yes. The Green Sahara, also known as the African Humid Period, was caused by the Earth's constantly changing orbital rotation around its axis, a pattern that repeats itself every 23,000 years, according to Kathleen Johnson, an associate professor of Earth systems at the University of California Irvine. 

However, because of a wildcard — human-caused greenhouse gas emissions that have led to runaway climate change — it's unclear when the Sahara, currently the world's largest hot desert, will turn a new green leaf. 

Related: Has the Earth ever been this hot before?

The Sahara's green shift happened because Earth's tilt changed. About 8,000 years ago, the tilt began moving from about 24.1 degrees to the current day 23.5 degrees, Space.com, a Live Science sister site, previously reported. That tilt variation made a big difference; right now, the Northern Hemisphere is closest to the sun during the winter months. (This may sound counterintuitive, but because of the current tilt, the Northern Hemisphere is tilted away from the sun during the winter season.) During the Green Sahara, however, the Northern Hemisphere was closest to the sun during the summer. 

This led to an increase in solar radiation (in other words, heat) in Earth's Northern Hemisphere during the summer months. The rise in solar radiation amplified the African monsoon, a seasonal wind shift over the region caused by temperature differences between the land and ocean. The increased heat over the Sahara created a low pressure system that ushered moisture from the Atlantic Ocean into the barren desert. (Usually, the wind blows from dry land toward the Atlantic, spreading dust that fertilizes the Amazon rainforest and builds beaches in the Caribbean, Live Science previously reported.)

This increased moisture transformed the formerly sandy Sahara into a grass and shrub-covered steppe, according to the National Oceanic and Atmospheric Administration (NOAA). As animals there prospered, humans did too, eventually domesticating buffalo and goats and even creating an early system of symbolic art in the region, NOAA reported. 

Wobbling Earth

But why did Earth's tilt change in the first place? To understand this monumental change, scientists have looked to Earth's neighbors in the solar system.

"The Earth's axial rotation is perturbed by gravitational interactions with the moon and the more massive planets that together induce periodic changes in the Earth's orbit," Peter de Menocal, the director at the Center for Climate and Life at Lamont-Doherty Earth Observatory  at Columbia University in New York, wrote in Nature. One such change is a "wobble" in the Earth's axis, he wrote. 

That wobble is what positions the Northern Hemisphere closer to the sun in the summer — what researchers call a Northern Hemisphere summer insolation maximum — every 23,000 years. Based on research first published in the journal Science in 1981, scholars estimate that the Northern Hemisphere had a 7% increase in solar radiation during the Green Sahara compared with now. This increase could have escalated African monsoonal rainfall by 17% to 50%, according to a 1997 study published in the journal Science. 

Related: Why does rain smell good?

What's interesting to climate scientists about the Green Sahara is how abruptly it appeared and vanished. The termination of the Green Sahara took only 200 years, Johnson said. The change in solar radiation was gradual, but the landscape changed suddenly. "It's an example of abrupt climate change on a scale humans would notice," she said.

"Records from ocean sediment show [that the Green Sahara] happens repeatedly," Johnson told Live Science. The next Northern Hemisphere summer insolation maximum — when the Green Sahara could reappear — is projected to happen again about 10,000 years from now in A.D. 12000 or A.D. 13000. But what scientists can't predict is how greenhouse gases will affect this natural climate cycle. 

Paleoclimate research "provides unequivocal evidence to what [humans] are doing is pretty unprecedented," Johnson said. Even if humans stop emitting greenhouse gases today, these gases would still be elevated by the year 12000. "Climate change will be superimposed onto the Earth's natural climate cycles," she said. 

That said, there's geologic evidence from ocean sediments that these orbitally-paced Green Sahara events occur as far back as the Miocene epoch (23 million to 5 million years ago), including during periods when atmospheric carbon dioxide was similar to, and possibly higher, than today's levels. So, a future Green Sahara event is still highly likely in the distant future. Today's rising greenhouse gases could even have their own greening effect on the Sahara, though not to the degree of the orbital-forced changes, according to a March review published in the journal One Earth. But this idea is far from certain, due to climate model limitations.  

Meanwhile, there is another way to turn parts of the Sahara into a green landscape; if massive solar and wind farms were installed there, rainfall could increase in the Sahara and its southern neighbor, the semiarid Sahel, according to a 2018 study published in the journal Science. 

Wind and solar farms can increase heat and humidity in the areas around them, Live Science previously reported. An increase in precipitation, in turn, could lead vegetation growth, creating a positive feedback loop, the researchers of that study said. However, this huge undertaking has yet to be tested in the Sahara Desert, so until such a project gets funding, humans might have to wait until the year 12000 or longer to see whether the Sahara will turn green again. 

Originally published on Live Science.

Easily separate your trash from recyclables with the iTouchless Dual Step Trash Can & Recycle Bin. Each section holds an 8-gallon container that holds liners if you choose to use them and are easy to remove to dump individually. There are several other options for holding your recyclable until trash day. Here are a few more to consider. 

This dual trash can and recycle bin is the best on the market. The iTouchless holds a combined 16 gallons of recyclables and trash, though you can use it exclusively for sorting recycles, too. Each side of the bin has its own lid and step pedal-style opening. Each side also has a removable bin, one blue and one black, to help with separating. The outside has a smudge-proof stainless steel finish that is easy to clean up and looks nice in most kitchens. There is a filtration system to help neutralize odors with removable filters. The only drawback is because each side only holds 8 gallons of material, this may not be big enough to use as intended as a dual trash can and recycle bin. Many households need a much bigger container for holding garbage. 

The Genuine Joe recycle bin holds up to 28 gallons of material. It’s made from heavy-duty plastic, so you don’t have to worry about it rusting or becoming crushed. It has the recycle symbol on the side and is the tell-tale blue color that distinguishes it from your trash can. This large capacity bin is good for in an office building where there is a lot of recyclables but it is also suitable in a home. The rectangle shape makes it easier to carry and lift when it’s time to be emptied, but the slimmer shape isn’t the easiest to pack material in. You’ll find, especially if you use bin liners, that there is a lot of empty space and it’s harder to compact recyclables into it. 

This is the perfect sized recycle bin to place beside your desk. It is compact and holds only 7 gallons of recyclables, but that is a lot for a single worker. And when it is time to empty the bin it won’t be too heavy. The bin is small enough to fit into garbage drawers in kitchens, too. This United Solutions wastebasket has the recycle symbol on its side and is a bright blue color so it’s easier to distinguish it from a traditional garbage can. It’s made from durable plastic that is easy to clean when it gets dirty. It doesn’t come with a lid, nor does it have a filtering system to help neutralize odors. 

Recycling isn’t just for paper, plastic, and glass. You can turn kitchen scraps, like apple cores, banana peels, and cherry pits into compost for your garden. The Abakoo compost bin sits on your countertop or under your sink for an easy to reach place to gather your organic recyclables. It holds over a gallon of scaps, which is about a week’s worth, so you don’t have to head out to the garden to dump it frequently. The handle has a rubberized grip to help you keep a firm hold on the bis are you move it. And it has a charcoal filtering system, along with four filters, to neutralize odors and keep your kitchen smelling okay. The filters aren’t reusable, so it will cost a bit to purchase more and keep up with the smell. 

These recycle bins help you separate your materials before you get to the recycling center. Each bin is a heavy-duty bag with handles to carry them individually, but they attach side-by-side to each other using velcro strips. The containers hold about 10 gallons each and are clearly marked with what should be collected in them - glass, paper, plastic, and cans. While these bags shouldn’t be washed in a washing machine, they are made with a material that is easy to simply wipe down if they get dirty. Also, it will take several uses before they stand up straight when empty. 

This recycle bin from Rubbermaid is designed to hold a lot of items outside your home, so you don’t need a big, overpowering bin inside the house. It’s on wheels to make it easier to haul to the curb on trash day and heavy-duty plastic to reduce rusting, fading, warping, or cracking in extreme weather conditions. The base is reinforced to hold several gallons of recyclables. This bin has contoured handles on either side so it feels more natural to carry without putting too much strain on your hands. It’s designed to be stackable with more bins when not in use and has clips on each side to hold bags or liners without them slipping as the bin is filled. There are different sizes of this outdoor bin with the largest sizes ranging from 20 gallons to 55 gallons. You also have nine color and design choices. It does come with a lid that isn’t very thick and isn’t attached to the bin itself. This means you will need to keep an eye on it while it’s off so it doesn’t get lost. 

Bottom line

One of the best ways to show concern for the environment is to recycle plastic, paper, cans, and glass. The iTouchless 16 Gallon Dual Step Trash Can & Recycle Bin makes this easy by giving your two bins in one holder, one for trash and one for recyclables. Each side has a different colored bin and can be removed and emptied individually. You open each side with its own pedal-style step and if you use liners for either or both of the bins, removing them won't interfere with the other bin and bag. Together this recycle bin holds 16 gallons, but it limits each side to 8 gallons. For several households, this may not be big enough and will require frequent emptying before trash day.

July 2019 may have been the single hottest month in recorded history, preliminary data from the World Meteorological Organization shows.

Global average temperatures from July 1 to July 29, 2019, met and possibly even surpassed the previous record for the hottest month ever, which was set in July 2016, U.N. Secretary-General António Guterres said in a news conference yesterday (Aug. 1).

"This is even more significant because the previous hottest month, July 2016, occurred during one of the strongest El Niños ever," Guterres said, referring to the semiannual climate cycle that shifts the Pacific Ocean's warmest water toward South America, affecting weather patterns around the world. July 2019, meanwhile, did not coincide with a strong El Niño — temperatures were just really, really hot, due to climate change, he added.

The month was characterized by relentless heat waves around the world. On July 25, numerous European countries — including Belgium, Germany and the Netherlands — experienced new national heat records with temperatures in excess of 104 degrees Fahrenheit (40 degrees Celsius). The city of Paris also recorded its hottest day ever at 108.6 F (42.6 C), while widespread droughts in India left millions of people without water.

The scorching July follows the hottest June ever recorded and puts 2019 on track to be among the top five hottest years in history, Guterres said.

"We are on track for the period from 2015 to 2019 to be the five hottest years on record," he said. "If we do not take action on climate change now, these extreme weather events are just the tip of the iceberg."

That iceberg, Guterres added, is rapidly melting. The ice sheets of Greenland alone lost a staggering 217 billion tons (197 billion metric tons) of ice last month — enough to raise global average sea levels by 0.02 inches (0.5 millimeters), according to The Washington Post. Meanwhile, unprecedented wildfires scorched so much of the Arctic that the smoke was visible from space, releasing about 100 megatons of carbon dioxide into the atmosphere from June 1 to July 21 — roughly the amount of CO2 that Belgium releases in a year, CNN reported.

The frequency and intensity of severe weather, natural disasters and record-smashing heat waves are all likely to increase year after year until the world's most developed nations take significant measures to reduce their greenhouse gas emissions, a group of scientists reported last month in the journal Nature Climate Change.

In a 2018 report, the U.N.'s Intergovernmental Panel on Climate Change (IPCC) wrote that reducing global temperature rise to 2.7 F (1.5 C) above preindustrial levels instead of 3.6 F (2 C) could result in hundreds of millions of people being spared from the deadliest dangers of climate change, including famine, drought and lethal heat waves. Humans have already warmed the planet by about 1.8 F (1 C) above pre-industrial levels and are poised to hit the 2.7-degree threshold as soon as 2030.

• Images of Melt: Earth's Vanishing Ice
• The Reality of Climate Change: 10 Myths Busted
• Top 10 Ways to Destroy Earth

Originally published on Live Science.

NEW YORK — "Oh my god!" a woman shouted. "It's a seal!"

She was seated on a bench near me on June 8 by Muscota Marsh, at the northern end of Manhattan. The critter's head bobbed above the water as a crowd of onlookers formed. The seal floated closer and closer, sometimes darting under the water for an extended period before reappearing a dozen or so feet away. The people looked at the seal, and the seal looked back. After a time, maybe intimidated by the crowd or maybe bored, it ducked under the water and disappeared.

The marsh is part of Inwood, Manhattan's northernmost neighborhood. Local residents have spotted the seal in the marsh and on a nearby floating dock for at least the past two summers. In that time, the creature's become a sort of living local attraction. Since that June 8 sighting, I've spotted the seal basking on a wooden dock near the marsh, and flopping in and out of the water to gasps and cheers from onlookers. Inwood residents share seal updates on social media, and stake out the marsh in hopes of catching sight of the creature. [Beastly Feasts: Amazing Photos of Animals and Their Prey]

"It comes up in conversations, it's something you want on your local to-do list," said Barry Kogan, an Inwood resident and educator with the Bronx-based garden and nature center Wave Hill.

Muscota Marsh, a salt marsh and estuary adjacent to Inwood Hill Park, was restored in 2014 as part of a deal that allowed Columbia University to build a football stadium nearby. Its NYC Parks web page lists the great blue heron and snowy egret among its frequent wild visitors. Still, the seal seems like an unlikely inhabitant of the waterfront between paved-over Manhattan (home to about 1.6 million people, according to the U.S. Census Bureau) and the Bronx (home to an estimated 1.4 million).

But experts in local marine life told Live Science that a seal hanging out in Manhattan isn't quite as strange as it sounds — though it's a bit unexpected to see one make a long-term summer home here.

"It's not that uncommon anymore," said George Jackman, an ecologist with Riverkeeper, a nonprofit organization dedicated to preserving New York's waters. "Seals are quite common in Staten Island [NYC's southernmost borough]. They're in the Rockaways [a peninsula in Queens abutting the Atlantic Ocean]. I've seen them in Pelham Bay [part of the East Bronx]. They're in the sounds. I've seen images of them on floating docks in the Hudson."

That's a big change from a few decades ago, when seals were a much rarer sight in the region.

"Years ago people used to shoot them. People felt that they would compete with them for fish," Jackman said. "Now they're protected. You can't even look at them cross-eyed," Jackman said.

The Marine Mammal Protection Act, passed in 1972 and updated in 1994, made it illegal to harass, feed, hunt, capture, collect or kill aquatic mammals — including seals — anywhere in the waters of the U.S, according to the Marine Mammal Center a marine mammal rescue organization in California. Jackman said the act has helped populations to rebound in the New York City area. The datapoint that best illustrates this rebound, he said, is the number of of seal strandings, which has significantly increased all over the region in the last two decades.

And as seal numbers grow, he said, it makes sense that some seals would start turning up in new and surprising places.

"We're going to see all of them more: more seals, more whales, more porpoises, more dolphins," Jackman said. "But also as they expand their populations, it's all about the ZIP code. It's the same as rent in New York City. The premier spots have the highest rent, and if you can't afford that you go elsewhere, and hit the outer boroughs. So this guy is probably in the 'outer boroughs' of the range."

More prime spots for seals tend to be closer to the ocean, so the Inwood seal, likely a young pup, was probably pushed out of the fancier spots.

Still, he said, it's unusual that the seal has stuck around through the summer. Most seals follow herring populations, which tend to return to river systems and spawning grounds in the winter and spring, then head out to sea as temperatures warm. (One great time and place to see New York City seals, Kogan said, is Pelham Bay in the winter, when large groups can sometimes be spotted laid out on rocks.) [Manatees Are Making a Comeback]

This particular seal seems to have settled into a comfortable niche, likely because it has an abundant food source, Jackman said. A representative for the New York State Department of Environmental Conservation (NYSDEC) told Live Science that improved water quality and reduced nitrogen levels have led to greater bait fish populations in the greater New York marine region, which might play a role in the appearance of predators like seals. The department also noted a broader trend of charismatic megafauna returning to their New York City habitats in recent years.

Jackman said that while Inwood's resident seal is exciting, many other charismatic creatures hang out in New York City.

"Humpback whales in the harbor, dolphins in the harbor, we have a migration that's as big as anywhere else in the world that goes up the Hudson each year," he said.

And the region's natural beauty came long before the steel and skyscrapers, he said.

"New York City was once the Garden of Eden. When Henry Hudson came here and they described the abundance and diversity of life, it was beyond the comprehension of these Europeans," he said, referring to the English captain who recorded his observations of the Hudson River Valley in the 16th century. "And then essentially all the land and the wildlife was clear-cut. And to see it coming back is a wonderful thing."

The main thing for New York residents interested in nature to do, he said, is pay attention and intentionally seek it out.

"Nature's everywhere in New York City. Sure, in Times Square there's going to be less diversity of life. But if you go out to the outer boroughs, we are blessed to have like 20% of the area of the city be parkland and [to be] surrounded by water."

The NYSDEC told Live Science that people should stay at least 50 yards away (46 meters) from seals, and offered the number for the New York Stranding Hotline at 631-369-9829. If an animal does appear stranded, the NYSDEC said, pictures and video can help officials assess its status.

"Life is everywhere. It's like the grass that grows between the cracks in the sidewalk. Life will always be pressing for new places," Jackman said.

• Images: Sharks & Whales from Above
• Deep Blue Sea: Winning Underwater Photographs
• Quest for Survival: Photos of Incredible Animal Migrations

Originally published on Live Science.

Scientists may have unraveled the mystery of what triggered decade-long droughts during medieval times in the American Southwest. These so-called megadroughts were so devastating that entire civilizations may have collapsed in their wake.

These findings suggest the risk of megadroughts may rise due to global warming, scientists added.

From the 800s to the 1400s, about a dozen megadroughts struck the American Southwest, and all lasted longer than a decade.

"There weren't a whole lot of people there compared to today, but prior work has suggested that a number of native societies in the Southwest experienced megadroughts that were tied to the collapse of their civilizations," said study lead author Nathan Steiger, a climate scientist at Columbia University's Lamont-Doherty Earth Observatory. "People don't think megadroughts are the only reason why they collapsed, but they do think they were major contributing factors."

These megadroughts mysteriously ceased in the American Southwest about the year 1600. Scientists have sought to uncover what caused these past giant dry spells to shed light on whether, how and where they might happen in the future. [Nature's Arches: Photos of Stunning Sandstone in the American Southwest]

"Eighty percent or more of the water used by the American West is used for agriculture," Steiger said. "A megadrought could fundamentally change how communities are supported, how farmers in the West and California in particular do work, what they plant, if farming is even possible or not."

Now, the researchers suggest they may have for the first time developed "a comprehensive theory for why there were megadroughts in the American Southwest, and why they stopped," Steiger said.

Steiger and his colleagues developed a global reconstruction of aquatic and climate data and sea-surface temperatures spanning the past 2,000 years. They identified 14 droughts lasting more than a decade, all of which took place before 1600.

The scientists found three key factors were apparently linked to each medieval megadrought. The first involved "positive radiative forcing" — that is, a rise in the amount of energy that Earth absorbed from the sun. The next involved warming in the North Atlantic Ocean. The last factor involved severe and frequent La Niña events — unusually cool waters in a belt 5,000 miles (8,000 kilometers) long across the equatorial Pacific Ocean that previous research found could trigger floods, heat waves, blizzards and hurricanes worldwide.

During medieval times in the American Southwest, a drop in volcanic activity — which would have spewed out ash to block the sun — along with an increase in solar activity such as solar flares likely increased the amount of heat the area absorbed (positive radiative forcing). The overall rise in heat would have dried out the area. At the same time, warmer Atlantic conditions combined with strong, frequent La Niñas could have reduced rainfall.

All in all, the scientists found La Niña events played a role that was twice as important at causing megadroughts as the other two factors. La Niña is Spanish for "little girl" and is the counterpart of El Niño, which is Spanish for "little boy" and involves unusually warm waters in the same area of the equatorial Pacific Ocean. South American fisherman named El Niño for the baby Jesus, after noticing that the ocean would heat up around Christmastime.

The researchers cautioned that any potential future megadroughts will remain difficult to predict, since future El Niños and La Niñas remain difficult to model and forecast. However, they also cautioned these megadroughts may return in the near future due to emissions of greenhouse gases such as carbon dioxide, which trap heat from the sun and boost positive radiative forcing,

The scientists detailed their findings online July 24 in the journal Science Advances.

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Originally published on Live Science.

Vikings thought it was a dead troll. Now, it's just dead ice.

Okjökull (or just "Ok," for short) is one of 400 ancient glaciers crowning the mountains of Iceland — at least, it was, until global warming shrank it so much that Ok officially lost its glacier status in 2014.

While Ok was the first casualty of climate change in Iceland, it probably won’t be the last. Iceland's glaciers are losing about 10 billion tons of ice every year, and all 400 of them will likely follow in Ok's cold, wet footsteps by the year 2200 without a serious reduction in greenhouse gas emissions in the coming decades. [8 Ways Global Warming is Already Changing the World]

Now, to memorialize the loss of Ok and the hundreds of other Icelandic glaciers that may share Ok's fate, researchers from Iceland and the United States have created a memorial plaque to forever mark the spot where Ok once towered over the landscape.

The plaque, which will be officially dedicated in an Aug. 18 ceremony at the site of the former glacier, is addressed simply to "the future" and sends a hauntingly simple message.

"Ok is the first Icelandic glacier to lose its status as a glacier," the plaque reads. "In the next 200 years all our glaciers are expected to follow the same path. This monument is to acknowledge that we know what is happening and what needs to be done. Only you know if we did it."

The text concludes with "415ppm C02," the current ratio of greenhouse gases in Earth's atmosphere — and likely the highest amount our planet has seen since before humans evolved.

"This will be the first monument to a glacier lost to climate change anywhere in the world," Cymene Howe, an anthropologist at Rice University in Houston and co-creator of a 2018 documentary on Ok, said in a statement. "By marking Ok's passing, we hope to draw attention to what is being lost as Earth's glaciers expire. These bodies of ice are the largest freshwater reserves on the planet and frozen within them are histories of the atmosphere."

Howe and her fellow researchers will install the plaque as part of an "un-glacier tour," which will depart from Reykjavík and lead participants on a free hike to the former site of Ok. Participants should expect rocky terrain.

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Originally published on Live Science.

Antarctica's western ice sheet is in danger of collapsing, but scientists may have an unusual solution: blasting trillions of tons of artificial snow across glaciers with snow cannons.

Spraying this artificial blizzard into the coastal area around Thwaites and Pine Island glaciers could stabilize the failing West Antarctic Ice Sheet (WAIS), reducing ice loss that could drive potentially catastrophic sea level rise, new research finds.

But as intriguing as that extreme solution may sound, there would be considerable drawbacks; the effort would be prohibitively expensive and could harm sensitive ocean ecosystems, the researchers reported. [Antarctica: The Ice-Covered Bottom of the World (Photos)]

Western Antarctica is particularly vulnerable to climate change; decades of climbing temperatures have thinned the ice to the point where an estimated 24% of ice sheets in the western part of the continent are in danger of collapse. What's more, the melt rate is speeding up, with meltwater now flowing into the sea five times faster than it did in 1992, when surveys first began, Live Science previously reported.

"Ice loss is accelerating and might not stop until the West Antarctic ice sheet is practically gone," said study co-author Anders Levermann, a physicist at the Potsdam Institute for Climate Impact Research (PIK) in Potsdam, Germany, and an adjunct senior research scientist at the Lamont-Doherty Earth Observatory at Columbia University in New York City.

Without intervention to stop ice loss in Antarctica, sea level rise could reach nearly 10 feet (3 meters) — and coastal metropolises "from New York to Shanghai," will pay the price should the continent's western ice sheet collapse, Levermann said in a statement.

In the study, Levermann and his colleagues created computer simulations to evaluate how weak coastal ice might be strengthened. They found that artificial snow spread on the surface of the ice sheet where glaciers meet the sea would prevent ice sheet collapse; the technique would mimic natural precipitation in Antarctica while delivering substantially more snow than what is normally deposited there by seasonal storms.

"In practice, this could be realized by an enormous redisposition of water masses, pumped out of the ocean and snowed onto the ice sheet," Levermann said.

The researchers' simulations showed that stabilizing the ice sheet would require at least 8 trillion tons (7.25 trillion metric tons) of artificial snow, distributed with cannon-like snowblowers over 10 years. Siphoning ocean water to make the snow could further reduce global sea level rise by about 0.08 inches (2 millimeters) per year, the scientists reported.

But making snow in Antarctica would need a lot of mechanical infrastructure. Seawater would have to be transported to the ice sheet surface — a distance of about 2,100 feet (640 meters) on average — and then distributed across an area of over 20,000 square miles (52,000 square kilometers), according to the study. The researchers estimated that it would take 12,000 wind turbines to generate enough power just to move the water; desalination and snow-making would require even more energy.

And the wind farm would have to be constructed close to the coastline, which could destroy a pristine ocean environment, home to a unique diversity of marine life.

This would be "an unprecedented effort for humankind in one of the harshest environments of the planet," the scientists wrote. However, the enormity of the threat to humanity from Antarctica's unchecked ice loss — and the subsequent sea level rise — demands drastic and unconventional solutions such as this one, Levermann said in the statement.

Nevertheless, the snow-making option should not be seen as an alternative to global reduction of greenhouse gas emissions from fossil fuels, which are the primary drivers of climate change, the scientists wrote in the study.

"This gigantic endeavour only makes sense if the Paris Climate Agreement is kept and carbon emissions are reduced fast and unequivocally," Johannes Feldmann, lead study author and PIK researcher, said in the statement.

The findings were published online July 17 in the journal Science Advances.

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Originally published on Live Science.

If you thought last month felt really, really hot, you were right. June 2019 was the hottest June on record for the globe. And, it was the second month in a row that balmy temperatures caused Antarctic sea ice coverage to reach a record low.

The sizzling average land and sea temperature of June 2019 was 1.71 degrees Fahrenheit (0.95 degrees Celsius) above the global average temp of 59.9 F (15.5 C), making June 2019 the hottest June in 140 years, according to the National Oceanic and Atmospheric Administration's (NOAA) National Centers for Environmental Information. Nine of the top 10 hottest Junes have occurred since 2010.

In the U.S., Alaska had its second-warmest June since the state started keeping records in 1925. And although the Hawaiian islands are pretty much always balmy, the tropical region experienced its hottest June this year as well. The same goes for the Gulf of Mexico. [The Reality of Climate Change: 10 Myths Busted]

Europeans sweated more than normal last month, too, having experienced the region's hottest June on record as a whole. Austria, Germany and Hungary each recorded their hottest June ever, and Switzerland had its second hottest.

Last month's blanket of warmth covered the globe so thoroughly that it reached our planet's melting poles. June 2019 was the 20th consecutive June with below-average sea ice coverage in the Arctic, and the fourth consecutive June with below-average sea ice coverage in the Antarctic. Ice coverage in the Antarctic was the smallest it's ever been for June in the 41-year record, surpassing the previous record low set in 2002 by 62,000 square miles (160,580 square kilometers).

June's high temperatures are on a par with the previous months of 2019. The year-to-date temperature across the globe is also 1.7 F (0.94 C) above the 20th century average of 56.3 F (13.5 C), tying for second hottest with January to June 2017. Only January to June 2016 was warmer.

Are these record high temperatures a result of climate change? Yup.

"Climate is, by definition, the long-term average of weather, over many years," Josef Werne, a professor of geology and environmental science at the University of Pittsburgh, previously told Live Science. "One cold (or warm) year or season has little to do with overall climate. It is when those cold (or warm) years become more and more regular that we start to recognize it as a change in climate rather than simply an anomalous year of weather," he said.

As extreme heat waves happen more often across the globe, and Earth's temperature continues to rise, it's getting harder to ignore the unpleasant effects of climate change. A study published in June in the journal Nature Climate Change found that the scorching trend is likely to continue every year if no action is taken to reduce greenhouse gas emissions.

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Originally published on Live Science.

Would you ever go on vacation to the North Pole? Unless you like subzero temperatures and Nordic-ski treks, probably not. But if you lived 56 million years ago, you might answer differently. Back then, you would have enjoyed balmy temperatures and a lush green landscape (although you would have had to watch out for crocodiles). That's because the world was in the middle of an extreme period of global warming called the Paleo-Eocene Thermal Maximum, when the Earth was so hot that even the poles reached nearly tropical temperatures.

But was the planet ever as hot as it is today, when every month the globe seems to be breaking one high-temperature record after another?

It turns out that the Earth has gone through periods of extreme warming more than once. The poles have frozen and thawed and frozen again. Now, the Earth is heating up again. Even so, today's climate change is a different beast, and it's clearly not just part of some larger natural cycle, Stuart Sutherland, a paleontologist at the University of British Columbia, told Live Science. [How Often Do Ice Ages Happen?] 

Earth's climate does naturally oscillate — over tens of thousands of years, its rotations around the sun slowly change, leading to variations in everything from seasons to sunlight. Partially as a result of these oscillations, Earth goes through glacial periods (better known as ice ages) and warmer interglacial periods.

But to create a massive warming event, like the Paleo-Eocene Thermal Maximum, it takes more than a change in the tilt of Earth's axis, or the shape of its path around the sun. Extreme warming events always involve the same invisible culprit, one we're all too familiar with today: a massive dose of carbon dioxide, or CO2.

This greenhouse gas was almost certainly responsible for the Paleo-Eocene Thermal Maximum. But how did CO2 concentrations get so high without humans around? Scientists aren't absolutely sure, said Sébastien Castelltort, a geologist at the University of Geneva. Their best guess is that volcanoes spewed carbon dioxide into the atmosphere, trapping heat, and perhaps melting frozen pockets of methane, a greenhouse gas more potent than CO2 that had been long sequestered under the ocean. Just because extreme warming events spurred by greenhouse gases have happened before, doesn't mean these events are harmless. Take, for instance, the Permian-Triassic extinction event, which struck a few million years before dinosaurs arose on the planet. If the word "extinction" isn't enough of a clue, here's a spoiler: it was an absolute disaster for Earth and everything on it.

This warming event, which occurred 252 million years ago, was so extreme that Sutherland calls it the "poster child for the runaway greenhouse effect." This warming event, which was also caused by volcanic activity (in this case, the eruption of a volcanic region called the Siberian Traps), triggered climate chaos and widespread death.

"Imagine extreme drought, plants dying, the Saharah spreading throughout the continent," Sutherland told Live Science.

Temperatures rose 18 degrees Fahrenheit (10 degrees Celsius). (This is compared with the 2.1 F (1.2 C) rise in temperature we've seen since humans began burning fossil fuels). Around 95% of marine life and 70% of terrestrial life went extinct.

"It was just too hot and unpleasant for creatures to live," Sutherland said.

It's uncertain how high greenhouse gas concentrations were during the Permian-Triassic extinction event, but they likely were far higher than they are today. Some models suggest they grew as high as 3,500 parts per million (ppm). (For perspective, today's carbon dioxide concentrations hover a little over 400 ppm — but that's still considered high).

But it's the rate of change in CO2 concentrations that makes today's situation so unprecedented. During the Permian Triassic extinction event, it took thousands of years for temperatures to rise as high as they did — according to some studies, as many as 150,000 years. During the Paleo-Eocene Thermal Maximum, considered an extremely rapid case of warming, temperatures took 10,000 to 20,000 years to reach their height.

Today's warming has taken only 150 years.

That is the biggest difference between today's climate change and past climatic highs. It's also what makes the consequences of current climate change so difficult to predict, Castelltort said. The concern isn't just "but the planet is warming." The concern is that we don't know how rapid is too rapid for life to adjust, he said. Based on past warming events, no experts could possibly say that the current rate of warming won't have dramatic consequences, he said. "We just don't know how dramatic," he added.

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Originally published on Live Science.

Want to help save the world from climate change? Then grab some seeds, or some seedlings, and start planting trees like there's no tomorrow.

At least 1 trillion of them, and fast.

That may sound like a lot of trees, but the Earth has room for their gnarled bows and branches. In a new study that excluded cities and agricultural areas, researchers found that the planet has nearly 3.5 million square miles (9 million square kilometers) to spare for trees. Such newly planted trees could cut carbon (a part of the greenhouse gas carbon dioxide) in the atmosphere by nearly 25%, bringing it down to levels not seen for nearly 100 years, the scientists said. [Image Gallery: A Rainbow of Fall Leaves]

The study shows where in the world these trees could be planted, and how much carbon they could store. (Trees take carbon dioxide from the atmosphere and use it in a process called photosynthesis, which allows them to grow, ultimately storing that carbon in their leaves and other parts.) Russia has the most space at 583,000 square miles (1.5 million square km), followed by the United States at 397,700 square miles (1 million square km), the researchers found. The next top contenders are Canada with 302,700 square miles (784,000 square km), Australia with 223,900 square miles (578,900 square km), Brazil with 191,900 square miles (497,000 square km), and China with 155,200 square miles (402,000 square km) available for new green shoots.

In all, this area is equal to about the size of the United States.

"We all knew restoring forests could play a part in tackling climate change, but we had no scientific understanding of what impact this could make," study senior author Thomas Crowther, an assistant professor of ecology at the Swiss Federal Institute of Technology, Zurich (ETH Zurich), said in a statement.

The team's calculation "shows clearly that forest restoration is the best climate change solution available today," Crowther added.

Planting trees in these regions would increase Earth's forest-covered land by a third, all without affecting land humans use for cities and agriculture. Once these trees have matured, they could store 225 billion tons (205 billion metric tons) of carbon, or about two-thirds of the 330 billion tons (300 billion metric tons) of carbon that humans have released into the atmosphere since the Industrial Revolution began.

The unfolding greenery could help limit Earth's warming climate. The most recent Intergovernmental Panel on Climate Change (IPCC) report found that adding an additional 3.8 million square miles (10 million square km) of forestland could limit climate change to 2.5 degrees Fahrenheit (1.5 degrees Celsius) by 2050. But this number may change, as climate change factors tend to accelerate quickly, meaning that even more trees than the IPCC calculated in their report may be needed to achieve that goal, the researchers said.

The Swiss team came up with their forecasts by using a dataset of nearly 80,000 forests and combining that with Google Earth Engine, which allowed them to make a predictive model of tree cover.

However, even if the trees are planted pronto, their effects won't be immediate.

"It will take decades for new forests to mature and achieve this potential," Crowther said. "It is vitally important that we protect the forests that exist today, pursue other climate solutions and continue to phase out fossil fuels from our economies in order to avoid dangerous climate change."

The study was published online yesterday (July 4) in the journal Science.

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Originally published on Live Science.

When news about the environment becomes grim, you might be overcome by an urge to hide or collapse.

On last week's episode of HBO drama "Big Little Lies," 9-year-old Amabella did both. The character's metallic boots were found sticking out of a classroom closet following a lesson on climate change, and the internet collectively nodded in recognition.

It turns out that anxiety, grief and despair about the state of the environment is nothing new. It even has a name: eco-anxiety. And according to psychologists, it's incredibly common. [Hypersex to Hoarding: 7 New Psychological Disorders]

According to a Yale survey conducted in December 2018, 70% of Americans are "worried" about climate change, 29% are "very worried" and 51% feel "helpless." Despite these striking statistics, most people don't realize how widespread eco-anxiety is, one psychologist told Live Science.

"[Ecoanxiety] is often hidden somewhat under the surface," Thomas Doherty, a clinical psychologist based in Portland, Oregon, told Live Science, "people aren't taught how to talk about it."

Still, over the past decade, eco-anxiety has gained increasing recognition from scientists and non-scientists alike. It's not listed in the Diagnostic and Statistical Manual, psychology's list of official diagnoses. That's partially because its symptoms are poorly defined, said David Austern, a clinical psychologist at NYU Langone Health. The American Psychological Association defines it as "a chronic fear of environmental doom." Eco-anxiety can range from day-to-day worry about the fate of the world, to Amabella's outright panic attack. Depending on whom you ask, it can even include the fear and panic attacks some natural disaster victims experience after the fact, Austern said. Its symptoms are largely the same as any other kind of anxiety; its only distinguishing factor is its cause, Austern said.

But that doesn't mean that psychologists aren't taking eco-anxiety seriously. In 2008, the American Psychological Association established a climate change task force. And in 2017, they published a 70-page report on the mental-health effects of climate change. This year, at their annual conference in Chicago, there will be four climate change related sessions.

A term like eco-anxiety, though nebulous, is important to create recognition for a very real phenomenon, Austern said. It helps people express what they're experiencing.

Psychologists agree it's important to open up a dialogue about the mental health effects of climate change. But they also agree that in most cases, eco-anxiety isn't a bad thing.

"It's a rational reply to a really serious problem," Maria Ojala, a psychologist at Örebro University in Sweden, told Live Science. That, she says, is why it could be dangerous to make it a clinical diagnosis.

"We have to ask, Is it more pathological for someone to be so worried about climate change or is it actually more pathological that people are not more worried about it?" Austern said. Anxiety is precisely the emotion that'll propel us to do something, he added. Conveniently, taking action Is also one of the most effective coping mechanisms for eco-anxiety, Ojala said.

But anxiety is only good for sparking action up to a certain point, Doherty said. A tenet of psychology, the Yerkes-Dodson law, holds that up to a certain point, arousal — how alert or worried you feel — leads people take action and perform better. But overly high levels of anxiety can become paralyzing. For example, one study described cases in which fear of extreme weather approached the level of phobia. Depending on how anxious you are, that's either incredibly convenient, or presents a catch-22 situation.

In these cases, anxiety becomes counterproductive to climate action, Doherty said, And it's important to seek help. Luckily, if you're too anxious to take action, fostering a sense of connection with one's environment and community can also help with symptoms. A recent study found that 2 hours per week in nature is enough to reap mental health benefits.

Despite its prevalence, eco-anxiety still goes under-recognized. It shouldn't be, Doherty said. "This 'Big Little Lies' episode clearly struck a chord with people," Doherty said. And that's a sign, he added, of how important a conversation this is to have.

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Originally published on Live Science.

Editor's Note: This story was updated at 1:55 p.m. E.D.T.

BELLEVUE, Wash. — There's a giant trove of frozen methane, or "fire ice," locked beneath our ocean's surface. If released, it could trigger tsunamis, landslides and release huge amounts of carbon into our already-warming atmosphere. But we have almost no idea how much there is or where to find it.

That's in part because frozen methane on our planet takes many more forms than we previously thought, and we are only now beginning to recognize some of them, Ann Cook, an associate professor in the School of Earth Sciences at The Ohio State University said during a presentation yesterday (June 25) here at the Astrobiology Science Conference. [8 Ways Global Warming Is Already Changing the World]

Fire and ice

Frozen methane, also known as methane hydrates, is made up of methane gas molecules locked inside frozen water crystals. It looks like ice, forms at low temperatures and high pressures in the ocean and is thought to contain 15% to 40% of Earth's carbon, Cook said.

Because frozen methane stores much of our planet's carbon, it likely plays a big role in the recycling of carbon between our atmosphere and living things. It's also a potential energy source — and a potential biohazard, she said.

If it "melts," the sudden release of methane into the ocean rapidly changes the nearby water pressure, which can lead to dangerous landslides and tsunamis, Cook told Live Science. Methane is also highly flammable when in its free form.

Despite its importance, "we are still trying to figure out how much methane hydrate there is on Earth and how it may interact with the ocean and atmosphere," she said. "We need to understand the way it forms or how it looks in the subseafloor to know these things."

Scientists can't agree on how much methane hydrate lurks below the ocean. Most say that frozen methane contains 2,000 gigatons of carbon, while others might say closer to 200 gigatons or even 5,000 to 10,000 gigatons lie beneath the ocean, she said.

Part of the confusion stems from the fact that frozen methane takes at least five forms, according to a review that will be published in an upcoming issue of Reviews of Geophysics.

Some types are well-known, such as the frozen methane that lies below active seafloor methane vents. Other types are more surprising, like those found in thin sands— those found a couple meters below the seafloor. "We did not understand how the methane could transport to these thin sands," Cook said. But now they have a few guesses and they hope to test them by drilling in these areas and gathering samples.

What's more, learning about frozen methane on our planet can help inform us about potential methane sources on other planets, Cook said.

Frozen methane can sometimes release the gas by "belching" or venting from places on the seafloor or permafrost environments. This could also be true on Mars, Cook said. "Just last week, a relatively high methane measurement on Mars suggests we may have the same kind of system happening on Mars, which is pretty exciting," she said.

On Earth, the presence of frozen methane is still dwarfed by water and other elements. But "I can imagine really exciting planets out there where you would have hydrates forming … and then floating up in the ocean [forming] icebergs of natural gas," she said during the talk.

Editor's Note: This story was updated to note that thin sands are under the seafloor, not off the beach.

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Originally published on Live Science.

When you drop your plastic waste into the recycling bin, it most likely makes its way around the world, where it can pose a health and security risk to developing countries, according to a new Guardian report.

The planet is getting buried under plastic: beaches are littered with it, sea life is choking on it, and a new report finds that we're even drinking a credit-card-size amount of plastic every week from our drinking water. Needless to say, recycling is a good idea.

Until it's done wrong. That plastic bottle that you drop into a recycling bin on the streets of New York isn't always broken down and crafted into a brand-new product. Sometimes, it ends up across the world in someone's backyard, taking its place among scores of supermarket bags and snack pouches. 

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The U.S. ships about 1 million tons of plastic waste overseas every year. Much of that plastic used to end up in China, where it was recycled — that is, until the country abruptly stopped most of the plastic waste imports in 2017. Now, a good part of U.S. plastic waste is shipped to the world's poorest countries for recycling, including Bangladesh, Laos, Ethiopia and Senegal, the Guardian reported.

Last year, about 68,000 shipping containers' worth of plastic recycling waste from the U.S. were shipped to developing countries, which mismanage over 70% of their own plastic waste, they wrote. For example, Malaysia dumps or improperly disposes 55% of its own plastic waste, yet it receives more U.S. recyclables than any other country, they wrote. What's more, an estimated 20% to 70% of plastic waste that goes to recycling facilities worldwide is unusable and discarded as trash, according to the report.

Beyond just having to live among the trash that litters their beaches and streets, the increasing number of plastic processing facilities that are popping up in these countries is posing health risks to citizens who live among contaminated water supplies and the smell of plastic fumes, they wrote.

This report is part of the Guardian's six-month-long Toxic America series.

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Originally published on Live Science.

In the Canadian Arctic, layers of permafrost that scientists expected to remain frozen for at least 70 years have already begun thawing. The once-frozen surface is now sinking and dotted with melt ponds and from above looks a bit like Swiss cheese, satellite images reveal.

"We were astounded that this system responded so quickly to the higher air temperatures," said Louise Farquharson, a co-author of the study and postdoctoral fellow at the Permafrost Laboratory at the University of Alaska Fairbanks.

Permafrost is ground that remains frozen for at least two years. It underlies about 15% of the unglaciated Northern Hemisphere and serves a critical role in the transfer of carbon from living things to the atmosphere, Farquharson said. [Photos: Perfectly Preserved Baby Horse Unearthed in Permafrost]

The researchers recorded permafrost thawing to depths that were not expected until air temperatures reached levels the Intergovernmental Panel on Climate Change has predicted will occur after 2090, according to one of its "moderate" climate change models. The IPCC, which is a body of the United Nations, provides scientific information to help guide countries' climate policies.

The researchers believe higher summer temperatures, low levels of insulating vegetation and the presence of ground ice near the surface contributed to the exceptionally rapid and deep thawing.

The most striking evidence is visible to the naked eye. As upper layers of permafrost thaw and ice melts, the land settles unevenly, forming what is known as thermokarst topography. Landscapes in the Canadian Arctic that had been defined by gently rolling hills are now pockmarked with ditches and small ponds. The ground at the northernmost study site sank by about 35 inches (90 centimeters) over the course of the study.

"We had this flat terrain when we started monitoring," Farquharson told Live Science. "In 10 or so years, we saw the landscape transform."

Their data allowed the researchers to interpret the topographical changes happening before their eyes.

"We were able to tie together air temperature and ground temperature with the formation of this thermokarst terrain," Farquharson said.

Global implications

The thawing has climatic implications for the globe and immediate ecological ramifications for the region. Thawing caused by higher air temperatures threatens to exacerbate global climate change.

"Permafrost is like a giant freezer that contains a lot of really delicious plant material and organics that aren't being decomposed by microbes," Farquharson said. "Thawing opens the freezer door" and allows the microbes to start converting that organic material into CO2.

In changing the physical makeup of the landscape, thermokarst also affects local ecosystems and waterways by inviting new plant growth, disrupting stable nutrient cycles and allowing for the sedimentation of streams and possibly coastal systems.

Determining the extent of new thermokarst development is difficult, but there is little doubt the problem is widespread. Farquharson and her team guess that about 231,000 square miles (600,000 square kilometers) of permafrost, or about 5.5% of the zone that is permafrost year-round, is vulnerable to rapid surface thawing.

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Originally published on Live Science.

Scientists and security analysts have warned for more than a decade that global warming is a potential national security concern.

They project that the consequences of global warming — rising seas, powerful storms, famine and diminished access to fresh water — may make regions of the world politically unstable and prompt mass migration and refugee crises.

Some worry that wars may follow.

Yet with few exceptions, the U.S. military's significant contribution to climate change has received little attention. Although the Defense Department has significantly reduced its fossil fuel consumption since the early 2000s, it remains the world's single largest consumer of oil — and as a result, one of the world's top greenhouse gas emitters.

A broad carbon footprint

I have studied war and peace for four decades. But I only focused on the scale of U.S. military greenhouse gas emissions when I began co-teaching a course on climate change and focused on the Pentagon's response to global warming. Yet, the Department of Defense is the U.S. government's largest fossil fuel consumer, accounting for between 77% and 80% of all federal government energy consumption since 2001.

In a newly released study published by Brown University's Costs of War Project, I calculated U.S. military greenhouse gas emissions in tons of carbon dioxide equivalent from 1975 through 2017.

Today China is the world's largest greenhouse gas emitter, followed by the United States. In 2017 the Pentagon's greenhouse gas emissions totaled over 59 million metric tons of carbon dioxide equivalent. If it were a country, it would have been the world's 55th largest greenhouse gas emitter, with emissions larger than Portugal, Sweden or Denmark.

The largest sources of military greenhouse gas emissions are buildings and fuel. The Defense Department maintains over 560,000 buildings at approximately 500 domestic and overseas military installations, which account for about 40% of its greenhouse gas emissions.

The rest comes from operations. In fiscal year 2016, for instance, the Defense Department consumed about 86 million barrels of fuel for operational purposes.

Why do the armed forces use so much fuel?

Military weapons and equipment use so much fuel that the relevant measure for defense planners is frequently gallons per mile.

Aircraft are particularly thirsty. For example, the B-2 stealth bomber, which holds more than 25,600 gallons of jet fuel, burns 4.28 gallons per mile and emits more than 250 metric tons of greenhouse gas over a 6,000 nautical mile range. The KC-135R aerial refueling tanker consumes about 4.9 gallons per mile.

A single mission consumes enormous quantities of fuel. In January 2017, two B-2B bombers and 15 aerial refueling tankers traveled more than 12,000 miles from Whiteman Air Force Base to bomb ISIS targets in Libya, killing about 80 suspected ISIS militants. Not counting the tankers' emissions, the B-2s emitted about 1,000 metric tons of greenhouse gases.

Quantifying military emissions

Calculating the Defense Department's greenhouse gas emissions isn't easy. The Defense Logistics Agency tracks fuel purchases, but the Pentagon does not consistently report DOD fossil fuel consumption to Congress in its annual budget requests.

The Department of Energy publishes data on DOD energy production and fuel consumption, including for vehicles and equipment. Using fuel consumption data, I estimate that from 2001 through 2017, the DOD, including all service branches, emitted 1.2 billion metric tons of greenhouse gases. That is the rough equivalent of driving of 255 million passenger vehicles over a year.

Of that total, I estimated that war-related emissions between 2001 and 2017, including "overseas contingency operations" in Afghanistan, Pakistan, Iraq and Syria, generated over 400 million metric tons of CO2 equivalent — roughly equivalent to the greenhouse emissions of almost 85 million cars in one year.

Real and present dangers?

The Pentagon's core mission is to prepare for potential attacks by human adversaries. Analysts argue about the likelihood of war and the level of military preparation necessary to prevent it, but in my view, none of the United States' adversaries — Russia, Iran, China and North Korea — are certain to attack the United States.

Nor is a large standing military the only way to reduce the threats these adversaries pose. Arms control and diplomacy can often de-escalate tensions and reduce threats. Economic sanctions can diminish the capacity of states and nonstate actors to threaten the security interests of the U.S. and its allies.

In contrast, climate change is not a potential risk. It has begun, with real consequences to the United States. Failing to reduce greenhouse gas emissions will make the nightmare scenarios strategists warn against — perhaps even "climate wars" — more likely.

A case for decarbonizing the military

Over the past last decade the Defense Department has reduced its fossil fuel consumption through actions that include using renewable energy, weatherizing buildings and reducing aircraft idling time on runways.

The DOD's total annual emissions declined from a peak of 85 million metric tons of carbon dioxide equivalent in 2004 to 59 million metric tons in 2017. The goal, as then-General James Mattis put it, is to be "unleashed from the tether of fuel" by decreasing military dependence on oil and oil convoys that are vulnerable to attack in war zones.

Since 1979, the United States has placed a high priority on protecting access to the Persian Gulf. About one-fourth of military operational fuel use is for the U.S. Central Command, which covers the Persian Gulf region.

As national security scholars have argued, with dramatic growth in renewable energy and diminishing U.S. dependence on foreign oil, it is possible for Congress and the president to rethink our nation's military missions and reduce the amount of energy the armed forces use to protect access to Middle East oil.

I agree with the military and national security experts who contend that climate change should be front and center in U.S. national security debates. Cutting Pentagon greenhouse gas emissions will help save lives in the United States, and could diminish the risk of climate conflict.

Neta C. Crawford, Professor of Political Science and Department Chair, Boston University

This article is republished from The Conversation under a Creative Commons license. Read the original article.

It seems every week there's a scary new report about how man-made climate change is going to cause the collapse of the world's ice sheets, result in the extinction of up to 1 million animal species and — if that wasn't bad enough — make our beer very, very expensive. This week, a new policy paper from an Australian think tank claims that those other reports are slightly off; the risks of climate change are actually much, much worse than anyone can imagine.

According to the paper, climate change poses a "near- to mid-term existential threat to human civilization," and there's a good chance society could collapse as soon as 2050 if serious mitigation actions aren't taken in the next decade.

Published by the Breakthrough National Centre for Climate Restoration in Melbourne (an independent think tank focused on climate policy) and authored by a climate researcher and a former fossil fuel executive, the paper's central thesis is that climate scientists are too restrained in their predictions of how climate change will affect the planet in the near future. [Top 9 Ways the World Could End]

The current climate crisis, they say, is larger and more complex than any humans have ever dealt with before. General climate models — like the one that the United Nations' Panel on Climate Change (IPCC) used in 2018 to predict that a global temperature increase of 3.6 degrees Fahrenheit (2 degrees Celsius) could put hundreds of millions of people at risk — fail to account for the sheer complexity of Earth's many interlinked geological processes; as such, they fail to adequately predict the scale of the potential consequences. The truth, the authors wrote, is probably far worse than any models can fathom.

How the world ends

What might an accurate worst-case picture of the planet's climate-addled future actually look like, then? The authors provide one particularly grim scenario that begins with world governments "politely ignoring" the advice of scientists and the will of the public to decarbonize the economy (finding alternative energy sources), resulting in a global temperature increase 5.4 F (3 C) by the year 2050. At this point, the world's ice sheets vanish; brutal droughts kill many of the trees in the Amazon rainforest (removing one of the world's largest carbon offsets); and the planet plunges into a feedback loop of ever-hotter, ever-deadlier conditions.

"Thirty-five percent of the global land area, and 55 percent of the global population, are subject to more than 20 days a year of lethal heat conditions, beyond the threshold of human survivability," the authors hypothesized.

Meanwhile, droughts, floods and wildfires regularly ravage the land. Nearly one-third of the world's land surface turns to desert. Entire ecosystems collapse, beginning with the planet's coral reefs, the rainforest and the Arctic ice sheets. The world's tropics are hit hardest by these new climate extremes, destroying the region's agriculture and turning more than 1 billion people into refugees.

This mass movement of refugees — coupled with shrinking coastlines and severe drops in food and water availability — begin to stress the fabric of the world's largest nations, including the United States. Armed conflicts over resources, perhaps culminating in nuclear war, are likely.

The result, according to the new paper, is "outright chaos" and perhaps "the end of human global civilization as we know it."

How can this catastrophic vision of the future be prevented? Only with the people of the world accepting climate change for the emergency it is and getting to work — immediately. According to the paper's authors, the human race has about one decade left to mount a global movement to transition the world economy to a zero-carbon-emissions system. (Achieving zero-carbon emissions requires either not emitting carbon or balancing carbon emissions with carbon removal.) The effort required to do so "would be akin in scale to the World War II emergency mobilization," the authors wrote.

The new policy paper was endorsed with a foreword by Adm. Chris Barrie, a retired Australian defense chief and senior royal navy commander who has testified before the Australian Senate about the devastating possibilities climate change poses to national security and overall human well-being.

"I told the [Senate] Inquiry that, after nuclear war, human-induced global warming is the greatest threat to human life on the planet," Barrie wrote in the new paper. "Human life on Earth may be on the way to extinction, in the most horrible way."

• The Reality of Climate Change: 10 Myths Busted
• Images of Melt: Earth's Vanishing Ice
• 50 Amazing Facts About Earth

Originally published on Live Science.

In the Chinese science fiction film The Wandering Earth, recently released on Netflix, humanity attempts to change the Earth's orbit using enormous thrusters in order to escape the expanding sun — and prevent a collision with Jupiter.

The scenario may one day come true. In five billion years, the sun will run out of fuel and expand, most likely engulfing the Earth. A more immediate threat is a global warming apocalypse. Moving the Earth to a wider orbit could be a solution — and it is possible in theory.

But how could we go about it and what are the engineering challenges? For the sake of argument, let us assume that we aim to move the Earth from its current orbit to an orbit 50% further from the sun, similar to Mars'.

We have been devising techniques to move small bodies — asteroids — from their orbit for many years, mainly to protect our planet from impacts. Some are based on an impulsive, and often destructive, action: a nuclear blast near or on the surface of the asteroid, or a "kinetic impactor", for example a spacecraft colliding with the asteroid at high velocity. These are clearly not applicable to Earth due to their destructive nature.

Other techniques instead involve a very gentle, continuous push over a long time, provided by a tugboat docked on the surface of the asteroid, or a spacecraft hovering near it (pushing through gravity or other methods). But this would be impossible for the Earth as its mass is enormous compared to even the largest asteroids.

Electric thrusters

We have actually already been moving the Earth from its orbit. Every time a probe leaves the Earth for another planet, it imparts a small impulse to the Earth in the opposite direction, similar to the recoil of a gun. Luckily for us — but unfortunately for the purpose of moving the Earth — this effect is incredibly small.

SpaceX's Falcon Heavy is the most capable launch vehicle today. We would need 300 billion billion launches at full capacity in order to achieve the orbit change to Mars. The material making up all these rockets would be equivalent to 85% of the Earth, leaving only 15% of Earth in Mars orbit.

An electric thruster is a much more efficient way to accelerate mass — in particular ion drives, which work by firing out a stream of charged particles that propel the vessel forward. We could point and fire an electric thruster in the trailing direction of Earth's orbit.

The oversized thruster should be 1,000 kilometres above sea level, beyond Earth's atmosphere, but still solidly attached to the Earth with a rigid beam, to transmit the pushing force. With an ion beam fired at 40 kilometres per second in the right direction, we would still need to eject the equivalent of 13% of the mass of the Earth in ions to move the remaining 87%.

Sailing on light

As light carries momentum, but no mass, we may also be able to continuously power a focused light beam, such as a laser. The required power would be collected from the sun, and no Earth mass would be consumed. Even using the enormous 100GW laser plant envisaged by the Breakthrough Starshot project, which aims to propel spacecraft out of the solar system to explore neighbouring stars, it would still take three billion billion years of continuous use to achieve the orbital change.

But light can also be reflected directly from the sun to the Earth using a solar sail stationed next to the Earth. Researchers have shown that it would need a reflective disc 19 times bigger than the Earth's diameter to achieve the orbital change over a timescale of one billion years.

Interplanetary billiard

A well-known technique for two orbiting bodies to exchange momentum and change their velocity is with a close passage, or gravitational slingshot. This type of manoeuvre has been extensively used by interplanetary probes. For example, the Rosetta spacecraft that visited comet 67P in 2014-2016, during its ten-year journey to the comet passed in the vicinity of the Earth twice, in 2005 and 2007.

As a result, the gravity field of the Earth imparted a substantial acceleration to Rosetta, which would have been unachievable solely using thrusters. Consequently, the Earth received an opposite and equal impulse — although this did not have any measurable effect due to Earth's mass.

But what if we could perform a slingshot, using something much more massive than a spacecraft? Asteroids can certainly be redirected by the Earth, and while the mutual effect on Earth's orbit will be tiny, this action can be repeated numerous times to ultimately achieve a considerable Earth orbit change.

Some regions of the solar system are dense with small bodies such as asteroids and comets, the mass of many of which is small enough to be moved with realistic technology, but still orders of magnitude larger than what can be realistically launched from Earth.

With accurate trajectory design, it is possible to exploit so-called "Δv leveraging" — a small body can be nudged out of its orbit and as a result swing past the Earth, providing a much larger impulse to our planet. This may seem exciting, but it has been estimated that we would need a million such asteroid close passes, each spaced about a few thousand years apart, to keep up with the sun's expansion.

The verdict

Of all the options available, using multiple asteroid slingshots seems the most achievable right now. But in the future, exploiting light might be the key — if we learn how to build giant space structures or super-powerful laser arrays. These could also be used for space exploration.

But while it is theoretically possible, and may one day be technically feasible, it might actually be easier to move our species to our planetary next-door neighbour, Mars, which may survive the sun's destruction. We have, after all, already landed on and roved its surface several times.

After considering how challenging it would be to move the Earth, colonising Mars, making it habitable and moving Earth's population there over time, might not sound as difficult after all.

Matteo Ceriotti, Lecturer in space systems engineering, University of Glasgow

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Glaciers and ice sheets in Antarctica have thinned and weakened dramatically over the past quarter-century, leaving 24% of the ice in the western part of the continent seriously weakened and in danger of collapse.

In some places on Antarctica, glaciers have thinned by approximately 400 feet (122 meters). This staggering loss has little to do with weather fluctuations; rather, it unfolded over decades as Earth's climate warmed, scientists reported in a new study.

And that ice loss is accelerating. The researchers found that West Antarctica's two biggest glaciers — Thwaites and Pine Island — are melting away five times faster now than they were at the beginning of the survey, in 1992. [Antarctica: The Ice-Covered Bottom of the World (Photos)]

To determine these ice changes, the scientists examined regional climate models and satellite data spanning 25 years, they reported May 16 in the journal Geophysical Research Letters.

They consulted 800 million measurements of ice sheet height in Antarctica, recorded between 1992 and 2017 by the European Remote Sensing (ERS) satellites ERS-1 and ERS–2, the Earth-observing satellite Envisat and the environmental research satellite CryoSat-2. All of the satellites were deployed by the European Space Agency.

Using these measurements, the researchers calculated the volume of Antarctica's ice mass separately from the fluctuating blankets of snowfall that accumulates and recedes in seasonal cycles, determining snowfall volume through computer simulations.

The scientists found that significant areas of the ice sheets across Antarctica showed signs of severe weakness, or "dynamical imbalance." This dynamical imbalance was most widespread in West Antarctica, destabilizing more than 160,000 square miles (415,000 square kilometers) of ice; and the lost mass wasn't being replenished by snowfall.

In the Antarctic Peninsula — the spike of land that extends northward from West Antarctica — an estimated 6,900 square miles (17,900 square km) of ice is also dangerously unstable, as is about 22,000 square miles (57,000 square km) of ice in East Antarctica, according to the study.

"Knowing how much snow has fallen has really helped us to detect the underlying change in glacier ice within the satellite record," said lead study author Andy Shepherd, director of the Centre for Polar Observation and Modeling in the United Kingdom.

"We can see clearly now that a wave of thinning has spread rapidly across some of Antarctica's most vulnerable glaciers, and their losses are driving up sea levels around the planet," Shepherd said in a statement.

Since 1992, melting ice in Antarctica alone has led to sea-level rise of about 0.2 inches (5 millimeters). That may not sound like much, but with the pace of ice melt accelerating — and with Antarctica holding Earth's biggest reserve of frozen, landlocked water — the prospect of much greater sea-level rise is looming, the scientists wrote.

• Images of Melt: Earth's Vanishing Ice
• In Photos: Research Vessel Headed to 'Hidden' Antarctic Ecosystem
• Photos of Melt: Glaciers Before and After

Originally published on Live Science.

In early February, Sen. Ed Markey (D-MA) and Rep. Alexandria Ocasio-Cortez (D-NY) introduced the Green New Deal (GND), a sweeping resolution that addresses the dual challenges of income inequality and climate change, and the first government policy document aimed at curbing climate change as one of its goals.

This is significant. The United Nations Intergovernmental Panel on Climate Change (IPCC) report released in October 2018 stated that there will have to be some removal of carbon dioxide (CO2) from the atmosphere — the first and most vital step in restoring the climate — in order to avoid the very worst impacts of climate change (including massive die-offs of coral reefs, flooding, hurricanes, wildfires and widespread droughts). 

Climate restoration is the principle of removing CO2 to get back to pre-Industrial Revolution levels, specifically below 300 parts per million (ppm), and restoring the world's ecosystems, such as increasing ice in the Arctic. In spite of the IPCC warning, governments and mainstream nongovernmental organizations have not targeted climate restoration in any meaningful way to date. [5 Ways Climate Change Will Affect Your Health] 

In line with the IPCC report, the GND set several 10-year targets that include keeping global temperatures less than 2.7 degrees Fahrenheit (1.5 degrees Celsius) above pre-industrial levels, meeting 100% of the country's energy needs through renewable and zero-emissions energy sources, and reducing greenhouse gas emissions to net zero by 2050. But the proposal also exceeds those goals by specifically calling for the removal of CO2 from the atmosphere and restoring natural ecosystems.

It's promising that the GND includes the removal of some atmospheric CO2, but the resolution stopped short of setting a specific target. That's a mistake. In order to restore a healthy climate, society should set a goal of reducing CO2 to levels less than 300 ppm by 2050. That means removing roughly a trillion tons of CO2 from the atmosphere (depending on how quickly emissions of the gas are reduced); a feasible goal, but one that will only be met if governments, scientists and private enterprise join forces.

A number of companies have developed the capacity to remove small amounts of atmospheric CO2 from power plants; a few are in the early stages of using technology to remove CO2 from the air. At scale, these machines will be able to remove massive amounts of CO2 from the Earth's atmosphere. A bipartisan-sponsored tax incentive for CO2 removal was included in last year's budget; the same group of lawmakers have proposed new legislation this year to promote further research and development of the technology.

Turning back the climate clock

Removing atmospheric CO2 is critical because we are currently at a level not seen since before humans evolved. For about 800,000 years, until the Industrial Revolution, global CO2 levels were, on average, 280 ppm. That's the level at which our species and civilization evolved, and the optimal level needed to cement a healthy future for our planet. That level of CO2 should also be the stated goal of the GND.

Scientists have long agreed that the highest level that might possibly be safe for humans is 350 ppm, which we exceeded in 1988. We passed 400 parts per million (ppm) in 2016 for the first time in millions of years. We are now at 410 ppm (March 2019), and at the current rate of growth, we could reach 500 ppm within 50 years. (To put these numbers in context, consider that our current CO2 increase rate is more than 100 times faster than the rise that occurred when the last ice age ended.)

With higher concentrations of CO2 come higher temperatures; it is impossible to keep global temperatures from rising without removing some CO2 from the atmosphere. The question is, how do we remove the CO2, where is it going to go and — most critically — who is going to pay for it? [8 Ways Global Warming Is Already Changing the World]

Climate restoration meets capitalism

There are two primary categories of CO2 removal methods.

The first is using technology to capture CO2 — directly from the air or from the exhaust from power plants (called flue gas) — and either pump it underground or turn it into products.

Companies tackling this challenge have developed technologies that can take CO2 directly from the air, and they're improving in efficiency every year. In order to finance the removal of CO2, they usually convert it into commercial products, although, with one exception, they don't have markets large enough to finance the removal of significant amounts of CO2. Moreover, when these companies insert captured CO2 into products such as fizzy drinks, enhanced oil recovery (EOR), and green fuels, the CO2 is released back into the atmosphere. To make a real impact on the climate, we must permanently sequester the carbon.

The second category of removal involves natural strategies, such as leveraging photosynthesis in the oceans and on land. Forests in the U.S. already store and sequester carbon, but at a rate of 3 metric tons of carbon for every acre per year, this process is a drop in the bucket.

Similarly, certain crops grown for human consumption (such as grasses and grains) sequester carbon in their roots. The advantage of these methods is that they are relatively inexpensive; the obvious downsides are that the roots rot over a few years — we are already fighting global deforestation — and there is simply not enough available (unused) land to grow the number of plants needed to sequester and store carbon at the requisite level.

Marine plants such as kelp, eelgrass and other sea vegetation naturally sequester carbon by sinking to the depths of the ocean, where the gas stays sequestered for hundreds to millions of years. Per acre, marine plants can remove up to 20 times more CO2 from the atmosphere than forests can on the land. Yet, like much of our marine life, flora in our seas is disappearing. Rising temperatures are decreasing seaweed communities and fish populations; productivity at some fisheries has been reduced by 15% to 35% over the past eight decades, a trend likely to accelerate as the oceans continue to warm. Technologists and entrepreneurs are working on ways to harness this natural process in order to absorb more CO2 and slow ocean acidification.

Having the technology to remove CO2 from the atmosphere and sequester it safely underground or underwater is only one side of the equation. The critical part is finding paying customers for the byproducts of CO2 removal. [Top 10 Ways to Destroy Earth]

The need for public and private investment

We currently have two existing markets in which to sell carbon from the atmosphere at the needed scale: seafood and rocks for construction.

The first is a bit speculative, first discussed by John Martin in 1988. Sales of fish and seaweed — byproducts of restored ocean photosynthesis — can pay for ocean restoration. Experts say that restoring about 1% of the ocean would be sufficient to remove all of the excess CO2 in our atmosphere by mid-century, while being paid for by the profits or taxes on fish and seaweed. One method, Marine Permaculture Arrays, currently being funded, in part by the Grantham Foundation, restores ocean health and grows seaweed by upwelling nutrient-rich deep seawater. Martin's method of using minute amounts of powdered iron ore to restore depleted fisheries was politically controversial in 2012, but is now making a comeback. The methods to ensure that large amounts of CO2 are sequestered safely by these processes are being perfected; research funding, either public or private, would accelerate this development and bring us climate restoration sooner.

Although oceans store a tremendous amount of carbon, carbonate rocks such as limestone store even more. Carbon dioxide from the air or from power plant exhaust can be mineralized above ground and sold. The gas can also be pumped underground into basalt rock, which actually converts the dangerous stuff into solid limestone (calcite minerals) in just a matter of months. Climeworks, the world's first commercial Direct Air Capture (DAC) plant, is doing precisely this sort of geological storage — which the company calls a "permanent solution."

Climeworks estimates the cost at scale to be $100 per ton of CO2; removing a trillion tons of CO2 this way could cost $100 trillion over 30 years. This solution is only feasible if governments pay for it; to put that in perspective, in 2017, global military spending was $1.7 trillion.

Aside from seafood, the market with the most potential to reach our CO2 removal goal is rocks used in construction. With the exception of water, aggregate is the most transported material on Earth. Consider the fact that, globally, we buy 50 billion tons of aggregates each year for use in concrete, asphalt, road base and buildings worldwide. Of this, 70% is limestone, a rock that is almost half CO2 by weight.

Therefore, synthetically converting CO2 to limestone makes sense from an economic standpoint, and is being done now. If suppliers shifted from quarried rock to synthetic limestone made from atmospheric CO2, we could remove and sell all the excess CO2 from the atmosphere by 2050. [Top 10 Craziest Environmental Ideas]

Scaling this up by 2030 might require $5 billion in corporate investment, but the benefit is that this solution supports itself, negating the need for government subsidies or additional taxes. (One company working on this is Blue Planet, in which the author is an investor.) The limestone is created locally where it's used, so it becomes more cost-efficient than quarried rock by reducing high transportation costs. Synthetic limestone is cost competitive when the quarry is more than 50 miles (80 kilometers) from the user. In large cities, the material must often be shipped from quarries hundreds of miles away. Blue Planet's synthetic limestone was recently used in the construction of San Francisco International Airport's Terminal 1 extension.

No time to waste

Foundations, activists and policymakers — including those who introduced the Green New Deal and those sponsoring legislation to promote carbon capture technologies — understand that removing atmospheric CO2 must be part of the solution in tackling climate change. It's a good first step.

Now it's time to move the needle and set a goal of getting CO2 levels back below 300 ppm by 2050. Removing a trillion tons of CO2 is a gargantuan task, and it's estimated to cost $100 trillion if governments buy the carbon, or a few hundred billion dollars if done wisely, utilizing existing commercial markets. Those numbers are almost incomprehensible, but that doesn't mean the task is impossible. We have the technology and we have the markets for the byproduct. Now we need a wholesale effort from the private sector to scale both. Let's get to work.

Peter Fiekowsky is the founder and president of Healthy Climate Alliance, a nonprofit education, networking and advocacy program of the Foundation for Climate Restoration, with the goal of restoring the climate. HCA serves as a bridge between the public, policymakers and technical and business experts. Fiekowsky is also a board member of Zynergy Capital and an MIT physicist; he contributed this article to Live Science's Expert Voices: Op-Ed & Insights.

The views expressed are those of the author and do not necessarily reflect the views of the publisher. This version of the article was originally published on Live Science.

Science popularizer Bill Nye told viewers of a popular late-night show that Earth is "on [expletive] fire" while lighting a globe with a blowtorch.

During his appearance on HBO's "Last Week Tonight With John Oliver" on Sunday (May 12), Nye used frank language to talk to millennials about the impacts of global warming on Earth. (Nye's comments are heavily edited here for language; viewer discretion is advised if you watch the video.)

"By the end of this century, if temperatures keep rising, the average temperature on Earth could go up another 4 to 8 degrees," Nye said to Oliver. (Nye was referring to degrees Celsius; the equivalent change in Fahrenheit is roughly 7 to 14 degrees). "What I'm saying is, the planet's on [expletive] fire."

He explained that addressing climate change means making tough choices in our daily lives to reduce carbon emissions, which are caused by activities such as driving vehicles or burning coal. These emissions produce greenhouse gases that trap heat in the atmosphere — warming the planet up, causing ocean levels to rise as glaciers melt, and increasing the severity of hurricanes and storms.

Nye, adding a few more expletives in his explanation, said none of these options to address global warming come free. So, he urged his viewers to grow up and make tough choices. "I didn't mind explaining photosynthesis to you when you were 12, but you're adults now. This is an actual crisis — got it?"

Oliver ended the segment by telling the audience that he was "absolutely onboard" with Nye's "gritty reboot."

Nye is best known for more family-friendly content, such as PBS's "Bill Nye the Science Guy" in the 1990s and, more recently, the Netflix series "Bill Nye Saves the World." He also is CEO of The Planetary Society, an advocacy group that promotes space exploration.

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Follow Elizabeth Howell on Twitter @howellspace. Follow us on Twitter @Spacedotcom and on Facebook.

There is more carbon dioxide in the atmosphere than there has been for 800,000 years — since before our species evolved.

On Saturday (May 11), the levels of the greenhouse gas reached 415 parts per million (ppm), as measured by the National Oceanic and Atmospheric Administration's Mauna Loa Observatory in Hawaii. Scientists at the observatory have been measuring atmospheric carbon dioxide levels since 1958. But because of other kinds of analysis, such as those done on ancient air bubbles trapped in ice cores, they have data on levels reaching back 800,000 years. [8 Ways Global Warming Is Already Changing the World]

During the ice ages, carbon dioxide levels in the atmosphere were around 200 ppm. And during the interglacial periods — the planet is currently in an interglacial period — levels were around 280 ppm, according to NASA.

But every story has its villains: Humans are burning fossil fuels, causing the release of carbon dioxide and other greenhouse gases, which are adding an extra blanket on an already feverish planet. So far, global temperatures have risen by about 1.8 degrees Fahrenheit (1 degree Celsius) since the 19th century or pre-industrial times, according to a special report released last year by the United Nation's Intergovernmental Panel on Climate Change.

Every year, the Earth sees about 3 ppm more carbon dioxide in the air, said Michael Mann, a distinguished professor of meteorology at Penn State University. "If you do the math, well, it's pretty sobering," he said. "We'll cross 450 ppm in just over a decade."

The subsequent warming is already causing changes to the planet — shrinking glaciers, bleaching coral reefs and intensifying heat waves and storms, among other impacts. And carbon dioxide levels higher than 450 ppm "are likely to lock in dangerous and irreversible changes in our climate," Mann told Live Science.

"CO2 levels will continue to increase for at least the next decade and likely much longer, because not enough is being done worldwide," said Donald Wuebbles, a professor of atmospheric sciences at the University of Illinois at Urbana-Champaign. "The long-term increase is due to human-related emissions, especially the emissions of our burning of fossil fuels."

However, he noted that the annual peak in carbon dioxide, which fluctuates throughout the year as plants change their breathing rhythms, occurs right now. The annual average value will be more like 410 to 412 ppm, he said. Which … is still very high.

"We keep breaking records, but what makes the current levels of CO2 in the atmosphere most troubling is that we are now well into the 'danger zone' where large tipping points in the Earth’s climate could be crossed," said Jonathan Overpeck, the dean of the School for Environment and Sustainability at the University of Michigan. "This is particularly true when you factor in the additional warming potential of the other greenhouse gases, including methane, that are now in the atmosphere."

The last time atmospheric carbon dioxide levels were this high, way before Homo sapiens walked the planet, the Antarctic Ice Sheet was much smaller and sea levels were up to 65 feet (20 meters) higher than they are today, Overpeck told Live Science.

"Thus, we could soon be at the point where comparable reductions in ice sheet size, and corresponding increases in sea level, are both inevitable and irreversible over the next few centuries," he said. Smaller ice sheets, in turn, might reduce the reflectivity of the planet and potentially accelerate the warming even more, he added.

"It's like we're playing with a loaded gun and don't know how it works."

• Images of Melt: Earth's Vanishing Ice
• The Reality of Climate Change: 10 Myths Busted
• 5 Ways Climate Change Will Affect Your Health

Originally published on Live Science.

The president of Indonesia wants to move the country's capital, Jakarta, to another location off the main island of Java, in part because the city of more than 10 million is sinking into the sea, according to news reports.

President Joko Widodo called the announcement an "important decision," according to the country's planning minister Bambang Brodjonegoro, BBC News reported.

The decision is in part due to research finding that parts of Jakarta will be completely submerged in just decades. [8 Ways Global Warming Is Already Changing the World]

"If we look at our models, by 2050 about 95% of North Jakarta will be submerged," Heri Andreas, a researcher at the Bandung Institute of Technology who studies Jakarta's land subsidence, told BBC News.

The surrounding Java Sea is also rising as a result of climate change, though that’s not happening quite as quickly as the land is subsiding, The New York Times reported in 2017.

Overcrowding and related traffic congestion — which has meant government ministers needing police escorts to get to meetings on time — also played roles in the decision to relocate the capital.

Widodo presented a preliminary relocation study to the National Development Planning Agency, also called Bappenas, during a cabinet meeting Monday (April 29), according to The Jakarta Post.

As for when the capital would move and where are not known. Since Indonesia gained its independence from the Dutch in 1945, its leaders have tried several times to do this with no success, according to the BBC.

The Bappenas head provided three alternatives to the Jakarta location at the meeting, according to the Post.

One idea is to establish a special government hub around the Presidential Palace and the National Monument in Jakarta, to improve efficiency. Another alternative floated is to move the capital about 31 to 43 miles (50 to 70 kilometers) outside Jakarta. The third option, which is the one the president has chosen, would be to relocate the capital completely off the island of Java.

That move would address the sinking as well as overcrowding, and potentially help spread economic opportunities beyond the megacity.

"We want to have a capital that represents the nation's identity and improves the efficiency of the central government and establish a smart, green and beautiful city," Bappenas head Bambang Brodjonegoro said during a press conference, the Post reported. "The capital relocation must serve the strategic vision of our long-term development agenda."

The main candidate for this third option is Palangkaraya, which is located in central Kalimantan on Indonesia's part of Borneo, the Post reported.

• The Reality of Climate Change: 10 Myths Busted
• Photographic Proof of Climate Change: Time-Lapse Images of Retreating Glaciers
• 10 Most Hazardous Countries For Volcanoes (Photos)

Originally published on Live Science.

Greenland's ice sheet is melting six times faster than it was in the 1980s. And all that meltwater is directly raising sea levels.

That's all according to a new study, published yesterday (April 22) in the journal Proceedings of the National Academy of Sciences, that carefully reconstructs the behavior of the ice sheet in the decades before modern measurement tools became available. Scientists already knew that there was a lot more ice on Greenland in the 1970s and 1980s. And they've had precise measurements of the increase in melting since the 1990s. Now they know just how dramatically things have changed in the last 46 years.

"When you look at several decades, it is best to sit back in your chair before looking at the results, because it is a bit scary to see how fast it is changing," University of California, Irvine, glaciologist Eric Rignot, a co-author of the study, said in a statement. [Image Gallery: Greenland's Melting Glaciers]

Greenland is just one island. But its ice sheet has the potential to transform the entire planet. The Greenland ice sheet has existed for 2.4 million years and is 2.1 miles (3.4 kilometers) thick at its deepest point. The whole thing weighs about half as much as Earth's whole atmosphere, or 6 quintillion — or 6 with 18 zeros after it — lbs. (2.7 quintillion kilograms). If it melted entirely, sea levels would rise by 24.3 feet (7.4 meters).

In the 21st century, scientists use laser measurements of the height of the ice, measurements of the ice sheet's total gravity and satellite photos to gauge changes in ice thickness. That's how they know that the sheet is melting four times faster now than it was in 2003, as Live Science previously reported.

To extend that record further into the past, the researchers divided Greenland into 260 "basins" of ice, which they studied individually using a combination of direct measurements of ice changes in satellite photos and sophisticated computer models of ice behavior. They found that between 1972 and 1980, Greenland actually gained roughly 100 trillion lbs. (47 trillion kg) of ice per year. The real mass loss, they found, started in the 1980s. Between 1980 and 1990, the island lost in the ballpark of 112 trillion lbs. (51 trillion kg) of ice per year. Between 1990 and 2000, it lost about 90 trillion lbs. (41 trillion kg) per year.

Then, in the 2000s, things dramatically accelerated.

Between 2000 and 2010, Greenland lost about 412 trillion lbs. (187 trillion kg) of ice per year. Between 2010 and 2018, the ice sheet lost roughly 631 trillion lbs. (286 trillion kilograms) of ice per year.

Those numbers make concrete what researchers and inhabitants of Greenland already knew: that the island is changing and its ancient glaciers are receding at an alarming rate. The dramatic uptick in ice loss in the last two decades coincides with a similar surge in atmospheric greenhouse gases and warming. As Live Science reported earlier this year, nine of the 10 warmest winters on record have happened since 2005.

What does this all mean for the future of the ice sheet, as well as global sea levels? As the Intergovernmental Panel on Climate Change concluded, that will depend primarily on what humans do next.

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Originally published on Live Science.

Gorner, going, gone

Gorner glacier, located near the Swiss border with Italy in the Monte Rosa massif, is the second largest glacier of the European Alps. This photo was taken in 2017. A group of scientists in Switzerland has predicted that Alpine glaciers like this one could be reduced to a few patches of ice by 2100 due to global warming. [Read more about the vanishing glaciers]

Running water

Water runs through this large moulin on Plaine Morte glacier during the annual drainage of an ice-dammed lake. The shrinking glaciers could have implications for water resources, hydroelectric power and tourism in the region.

Melting the Alps

New climate models have shown that if little is done to curb carbon emissions and slow global warming, about 95% of the ice volume of the glaciers in the European Alps will be lost by the end of the century. Even if warming is limited to 3.6 degrees Fahrenheit (2 degrees Celsius), about two-thirds of the ice will vanish. Shown here is the Plaine Morte glacier, the largest plateau glacier in the European Alps.

Blanketing ice

During the last ice age, Rhône glacier, shown here, was the largest glacier of the European Alps, covering much of Switzerland. Since 1856, the ice has retreated 4,600 feet (1,400 meters). To better reflect the sunlight and slow the melting, white blankets (seen at the edge of the glacier) are sometimes draped over the ice.

Pizol glacier

Pizol glacier, in northeastern Switzerland, is likely to disappear in the near future. Swiss scientists have predicted that half of the ice volume of glaciers in the Alps will disappear by 2050, regardless of how carbon emissions change over the next several decades.

Findel glacier

Findel glacier, located in the Monte Rosa massif, ends at an altitude of about 8,200 feet (2,500 m). Researchers have estimated that even under an intermediate global warming scenario, there will be no more glaciers at all below 8,200 feet in the Alps by 2100.

Aletsch glacier

In 2017, the nearly 4,000 individual glaciers had a total volume of about 24 cubic miles (100 cubic kilometers). The Aletsch glacier, shown here, is the largest glacier in the European Alps with an estimated volume of about 2.8 cubic miles (12 cubic kilometers).

The glaciers that cover the European Alps could disappear by 2100 if human-caused global warming greatly increases over the next several decades, according to new climate models.

"In a bad case, everything will almost be gone," Harry Zekollari, a climate scientist with the Swiss Federal Institute of Technology in Zurich, told reporters Tuesday (April 9) at the annual meeting of the European Geosciences Union (EGU) in Vienna.

Even if humans manage to prevent further global warming, the glaciers will still lose half their volume by 2050, Zekollari and his colleagues found. The researchers simulated the evolution of nearly 4,000 individual glaciers in the European Alps with a new computer model. Scientists used 2017 as their baseline year, with the glaciers starting out at a volume of about 24 cubic miles (100 cubic kilometers), or the equivalent of 40 million Olympic-size swimming pools. [Time-Lapse Images of Retreating Glaciers]

The researchers looked at how the glaciers would change based on different global warming scenarios outlined by the U.N. Intergovernmental Panel on Climate Change (IPCC) in 2013, known as representative concentration pathways, or RCPs.

The researchers found that about 95% of the ice would disappear under the most pessimistic warming scenario, RCP8.5, which projects that the global temperature average could rise by up to 8.6 degrees Fahrenheit (4.8 degrees Celsius) by 2100.

This would mean "you just have some disconnected ice patches at high elevation, but you don't really have any glaciers anymore," Zekollari said during the press conference.

Even under a more-intermediate warming scenario — RCP4.5 — 80% of the glacier volume would vanish, with no glaciers at all below an altitude of about 8,200 feet (2,500 meters), the study found.

Under a more limited emissions scenario known as RCP2.6 (a rise of less than 3.6 F, or 2 C), about one-third of the present-day glacier volume would remain in 2100. That's the "mini good news" of the report, Zekollari said, as it's better than the other scenarios but still greater loss than previously estimated.

Whichever global warming scenario plays out in the next few decades, the glaciers will shrink by half by 2050, because glaciers have a slow response time, Zekollari explained. [See Photos of the Vanishing Glaciers in Europe's Alps]

"The way they're going to look in the coming decades is in fact dictated by how they look now," he said.

Vanishing glaciers will affect the water supply, the hydroelectric power industry and the tourism industry in the Alps, Zekollari said.

"Unfortunately, the situation in the Alps is characteristic for what happens to mountain glaciers outside of the polar regions," Daniel Farinotti, the senior author of the study, also from the Swiss Federal Institute of Technology, told Live Science.

Earlier this year, Farinotti published another study in the journal Nature Geoscience that compiled data on ice thickness from more than 200,000 glaciers to get a global census of ice volume, excluding the ice sheets in Greenland and Antarctica. That study found that the total volume of glaciers around the world is about 38,000 cubic miles (160,000 cubic km), about 18% less than previous studies had estimated, meaning that many glaciers could disappear sooner than expected.

The new findings were published April 9 in EGU's journal The Cryosphere.

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Original article on Live Science.

Humans are living through a dramatic transformation of the planet's surface due to climate change, with the most obvious sign being the rapid decline in Arctic sea ice. And now, imaging has revealed perhaps a new chapter in that decline: The Bering Sea, which under normal circumstances should remain frozen-over until May, is almost entirely free of sea ice in early April.

Part of what makes this event so stunning, as the National Oceanic and Atmospheric Administration (NOAA) pointed out in a statement, is that the Arctic sea ice should be reaching its annual maximum right now. The summer reduction in sea ice normally only begins around now. And that process has, throughout recorded history, left the region between Russia and Alaska frozen at this time of year. But 2019 already has the lowest Arctic sea ice extent on record (beating 2018, which was also a record-breaker). And that's manifesting in an unseasonably liquid sea off Alaska's northwest coast.

The dramatic ice-melt in the Arctic won't drive up sea levels directly. That ice was already floating in the ocean, so it already counted toward the ocean's total volume. But the melting will have tangible effects both on the planet's climate and on the people and economies that rely on the Arctic region. [In Photos: Devastating Wildfires in California]

As Live Science has previously reported, surface ice acts as a kind of climate regulator. The surface of ice is bright white, so it reflects sunlight back into space. When the planet has lots of ice on its surface, less of the sun's energy stays on Earth, and the planet warms more slowly.

But open water is darker and absorbs more sunlight, turning it into heat. So, while sea ice loss is caused by climate change, it also causes climate change to speed up.

A more immediate impact: The loss of ice cover on the Bering Sea means the water there will be warmer this year, according to NOAA.

"This low ice extent has had a substantial economic impact on the coastal communities that rely on the ice for crabbing, fishing and even walrus hunting," NOAA said in its statement.

Commercial fisheries are also likely to be affected for years, the agency said.

At this point, the decline in Arctic sea ice is likely to continue for a long time. But the question of how far that decline will go is wrapped up in questions of how much carbon and other greenhouse gases humans continue to pump into the atmosphere — behaviors that lead to planet warming and ice melt. The sea ice loss we're seeing now is happening in the context of a world warmed by 1 degree Celsius (1.8 degrees Fahrenheit) above pre-industrial levels. A world warmed by 1.5 degrees C (2.7 degrees F) would involve even more-extreme and life-threatening changes, according to the International Panel on Climate Change (IPCC). And a world warmed 2 degrees C (3.6 degrees F) would look dramatically different even from that – with longer heatwaves, less food available, and more regions of the planet becoming dangerous to inhabit. A world warmed by 3 degrees C (5.4 degrees F), would be even more dramatically different. And so on.

The question of whether that happens has less to do at this point with natural forces than collective human decisions.

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Originally published on Live Science.

Six Neanderthals who lived in what is now France were eaten by their fellow Neanderthals some 100,000 years ago, according to gruesome evidence of the cannibalistic event discovered by scientists in a cave in the 1990s.

Now, researchers may have figured out why the Neanderthals, including two children, became victims of cannibalism: global warming.

While prior studies have interpreted Neanderthal remains to find proof of cannibalistic behavior, this is the first study to offer clues as to what may have led Neanderthals to become cannibals. Scientists found that rapid shifts in local ecosystems as the planet warmed may have extinguished the animal species that Neanderthals ate, forcing them to look elsewhere to fill their bellies. [25 Grisly Archaeological Discoveries]

The researchers examined a layer of sediment in a cave known as Baume Moula-Guercy, in southeastern France. There, excavations in 1999 by another team of scientists had uncovered 120 Neanderthal bones from six individuals that showed signs of being cannibalized.

Later, in 2014, another group of researchers analyzed the cave deposits to a depth of 26 feet (8 meters), dividing them into 19 layers associated with three climate shifts. For the new study, the authors turned their attention to layer 15, a silty sediment layer about 16 inches (40 centimeters) thick, covering approximately 98 to 131 feet (30 to 40 m) of the cave floor.

In that layer, charcoal and animal bones were so well-preserved that scientists could reconstruct an environmental snapshot representing 120,000 to 130,000 years ago. They discovered that the climate in the area was likely even warmer than it is today, and that the transition from a cold, arid climate to a warmer one happened quickly, "maybe within a few generations," study co-author Emmanuel Desclaux, a research associate at the University of Nice Sophia Antipolis in France, told Cosmos magazine.

As the animals that once populated the landscape vanished, some Neanderthals ate what they could find — their neighbors.

Cannibalism is by no means exclusive to Neanderthals, and has been practiced by humans and their relatives "from the early Palaeolithic to the Bronze Age and beyond," the study authors reported. The behavior adopted by the starving Neanderthals in the Baume Moula-Guercy should therefore not be viewed as "a mark of bestiality or sub-humanity," but as an emergency adaptation to a period of severe environmental stress, according to the study.

The findings were published online in the April issue of the Journal of Archaeological Science.

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Originally published on Live Science.

Eye on the ice

New ice forms in the Laptev Sea along the coast of Russia. New research finds that new sea ice, as seen in gray in this image, now usually melts near the coast instead of traveling through the open Arctic Ocean. This change, caused by rapid warming in the Arctic region, might alter the way nutrients, algae and other particles travel through the ocean.

Traveling Ice

Sea ice forms in the Barents Sea, Kara Sea, Laptev Sea and East Siberian Sea in the wintertime, when temperatures regularly hit 40 below (Celsius and Fahrenheit). The ice forms in less than 100 feet (30 meters) of water in places where rivers dump lots of terrestrial sediments and nutrients. Thus, ice formed in these seas tends to be rich in nutrients, sediments and other biogeochemical components. Strong winds blow the ice out to sea. If it doesn't melt, the ice gets caught up in the Transpolar Drift, a wind-driven current that eventually takes the ice southward toward the Fram Strait and out of the Arctic, where it melts.

The Transpolar Drift

The Transpolar Drift is a major highway for the transport of nutrients throughout the Arctic Ocean. But today, only 20 percent of sea ice formed in the Russian continental shelf seas makes it to the Fram Strait, according to research published April 2, 2019, in the journal Scientific Reports. In 2000, that number was 50 percent. Researchers are working to find out how this decline is affecting the chemistry and ecosystem of the Arctic Ocean.

Dirty Ice

Sediment-rich ice can be seen caught in the Transpolar Drift. Two researchers collect samples from a crane bucket lowered from the research vessel Polarstern. Scientists are trying to understand the movement of algae, nutrients, sediments and even pollutants from the Russian coastline into the central Arctic.

Sampling the Ice

Calf-deep in meltwater, two researchers from the Alfred Wegener Institute take an ice core from the pack ice in the Arctic Ocean. Using these samples, scientists can measure the sediments trapped within the ice. An upcoming expedition, called MOSAiC, will provide the most detailed look yet at the ice composition in the Transpolar Drift. An international group of scientists will deliberately freeze a research vessel into the pack ice. The vessel (staffed by rotating crews) will drift with the ice for a year.

Cold Work

Alfred Wegener Institute researchers take ice samples during a 2017 expedition on the icebreaker Polarstern. Researchers also measure ice thickness on such expeditions. These on-the-ice surveys, combined with satellite observations and aerial flybys, show that ice in the Fram Strait between Greenland and Svalbard is 30 percent thinner today than it was in the early 2000s.

Trapped in Ice

A researcher holds up an ice core taken during an expedition on the icebreaker Polarstern. The color of the ice shows clearly what's trapped inside: sediments, nutrients, perhaps algae. Understanding how the disrupted transport of these materials is affecting the Arctic is a major goal of researchers at the Alfred Wegener Institute.

Take to the skies

To track sea ice, researchers at the Alfred Wegener Institute developed a program called AWI IceBird. Two planes, Polar 5 and 6, use special electromagnetic instruments to measure ice thickness. The research shows that ice in the Transpolar Drift now forms primarily in the open sea. Ice from coastal areas almost always melts before it can reach the circulating current.

Monitoring the melt

Inside one of the AWI IceBird planes, scientists have a bird's-eye view of the melting Arctic. The region is in crisis. According to the National Oceanographic and Atmospheric Administration, surface air temperatures in the Arctic are warming twice as fast as the rest of the globe, and populations of wild reindeer and caribou have dropped by half over two decades. Sea ice has also hit its lowest extent on record in the last 12 years, according to the latest NOAA data.

Opening waters

Ice and open water in the Arctic, as seen from one of AWI IceBird's planes. Scientists expect that the Arctic summers will be ice-free between the 2040s and the 2060s. According to researchers at the Alfred Wegener Institute, the melt of Russian coastal ice before it reaches the open sea is one more step toward that ice-free future.

The glacier — known as Jakobshavn, which sits on Greenland's west coast — is still contributing to sea level rise, but it's losing less ice than expected. Instead of thinning and retreating inland, its ice is thickening and advancing toward the ocean, the researchers found.

The big question: Why is this happening? [Images: Greenland's Gorgeous Glaciers]

After much sleuthing, a team of scientists from the United States and the Netherlands found that the glacier is likely growing due to colder ocean currents. In 2016, a current that passes by Jakobshavn Glacier was cooler than usual, making waters near the glacier the coldest they'd been since the mid-1980s.

This cooler current came from the North Atlantic Ocean, more than 600 miles (966 kilometers) south of the glacier, according to data from NASA's Oceans Melting Greenland (OMG) mission and other observations.

The finding took the scientists completely by surprise. "At first, we didn't believe it," study lead researcher Ala Khazendar, a scientist at NASA's Jet Propulsion Laboratory in Pasadena, California, said in a statement. "We had pretty much assumed that Jakobshavn would just keep going on as it had over the last 20 years." But the cold water isn't a one-off. Data from OMG shows that the water has been cold now for three years in a row.

It appears that the cold water is the result of a climate pattern known as the North Atlantic Oscillation (NAO), which makes the northern Atlantic Ocean slowly switch between warm and cold water about once every 20 years, the researchers said. The cold phase just recently started, and has cooled the Atlantic Ocean in general, they said. In addition, some extra cooling of the waters around Greenland's southwest coast helped keep the glacier chilly.

But this crisp change won't last forever. Once the NAO climate pattern flips back, the Jakobshavn will likely start melting faster and thinning again, the researchers said.

"Jakobshavn is getting a temporary break from this climate pattern," Josh Willis, of the Jet Propulsion Laboratory and the principal investigator of OMG, said in the statement. "But in the long run, the oceans are warming. And seeing the oceans have such a huge impact on the glaciers is bad news for Greenland's ice sheet."

Huge ice loss … then small gain

Scientists have watched Jakobshavn with concern for decades. After losing its ice shelf in the early 2000s (an ice shelf forces a glacier to flow more slowly into the ocean, like dirt clogging a drain), Jakobshavn began losing ice at an alarming rate. Between 2003 and 2016, its thickness (from top to bottom) dwindled by 500 feet (152 meters).

But in 2016, the waters flowing from Greenland's southern tip to its western side cooled by more than 2.7 degrees Fahrenheit (1.5 degrees Celsius). Meanwhile, the NAO climate pattern caused the Atlantic Ocean near Greenland to cool by about 0.5 F (1 C) between 2013 and 2016. By the summer of 2016, these cooler waters reached the glacier, and they are likely the reason that Jakobshavn slowed its rate of ice loss to the ocean, the researchers said. [Image: Greenland's Dramatic Landscape]

In all, Jakobshavn grew about 100 feet (30 m) taller between 2016 and 2017, the researchers found. But, as mentioned, the glacier is still contributing to ocean level rise worldwide, as it's still losing more ice to the ocean than it is gaining from snow accumulation, the researchers said.

The findings shed light on how much ocean temperatures can affect glacier growth, said Tom Wagner, a NASA Headquarters program scientist for the cryosphere, the frozen part of Earth.

"The OMG mission deployed new technologies that allowed us to observe a natural experiment, much as we would do in a laboratory, where variations in ocean temperatures were used to control the flow of a glacier," Wagner, who was not involved in the study, said in the statement. "Their findings — especially about how quickly the ice responds — will be important to projecting sea level rise in both the near and distant future."

The study was published online March 25 in the journal Nature Geoscience.

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Originally published on Live Science.

On Jan. 31, 2002, a vast crescent of ice about the size of Rhode Island splintered off of the coast of Antarctica and spilled a flotilla of massive, melting icebergs into the sea. By March, some 1,250 square miles (3,250 square kilometers) of ice had melted away from the continent's edge, undoing more than 10,000 years of growth and stability in a little more than a month.

NASA scientists monitoring the ancient ice sheet — formerly known as the Larsen B Ice Shelf — were startled by the sudden collapse; never had the researchers witnessed so much ice disappear so quickly.

They did have some warning, though. In the months preceding the collapse, the shelf's surface had become riddled with more than 2,000 meltwater lakes — large pools of melted ice and snow that form on the surfaces of ice shelves during the summer melting season. These seasonal reservoirs can contain more than a million tons of water apiece and, according to a new study published today (Feb. 13) in the journal Nature Communications, may actually be able to bend portions of huge ice shelves so much that they break in half, ushering in their spectacular demise. [Photos: Diving Beneath Antarctica's Ross Ice Shelf]

"That's most likely what happened to Larsen B in 2002," lead study author Alison Banwell, a visiting researcher at the Cooperative Institute for Research In Environmental Sciences (CIRES), said in a statement.

To bend a glacier

After the 2002 collapse, researchers suspected meltwater pools had something to do with Larsen B's sudden demise (on top of myriad other factors, including drastically warming Antarctic waters). However, direct evidence of this hypothetical lake strain was lacking.

In November 2016, Banwell and her colleagues sought some cold, hard proof. Through a combination of legwork and satellite imagery, the researchers scouted out four large lake basins on Antarctica's McMurdo Ice Shelf (one piece of the massive Ross Ice Shelf, the continent's largest) that would soon fill with summer meltwater.

At each lake site, the team hammered down a metal pole containing GPS and pressure-sensing equipment to measure changes in ice elevation and water depth over the coming melt season. Three months later, the team retrieved the equipment via helicopter (the ice had since become too thin for overland travel).

Each lake left a clear imprint on the ice sheet. According to the team's sensors, the center of each lake had sunk between 3 and 4 feet (about a meter) as water filled each basin, then bounced back up again after the water had drained. Ice just 1,500 feet (half a kilometer) away showed hardly any vertical movement at all.

While the bending caused by the meltwater lakes filling and draining did not fracture the McMurdo Ice Shelf, the team used some mathematical models to estimate that a group of slightly larger lakes clustered more closely together could indeed cause the whole shelf to break apart.

These findings make it clear that the added weight of thousands of seasonal meltwater lakes played a role in the precipitous collapse of Larsen B. The precise extent of that meltwater damage is impossible to know — however, the CIRES researchers are confident that their models could help scientists predict the breakup of large ice shelves more accurately in the future. With seemingly every new year setting heat records, and the Arctic (the other home to the world's massive ice sheets) warming two to three times as quickly as the rest of the planet, there's no question those models will be needed.

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Originally published on Live Science.

Fifty-two hungry polar bears have occupied Guba, a work settlement in a remote Russian Arctic archipelago. The animals reportedly attacked locals, ransacked garbage dumps and barged into residential buildings, according to a government statement translated from Russian and released this weekend.

The massive invasion of polar bears prompted regional officials to declare a state of emergency on Saturday (Feb. 9).

"People are scared, afraid to leave the house … afraid to let their children go to school," Zhigansha Musin, a local school administrator, said in the statement. "Constantly in the village are from six to 10 polar bears."

Belushya Guba is a settlement of about 2,000 people in Russia's remote Novaya Zemlya archipelago, which is best known for its spooky plankton blooms and apocalyptic nuclear bomb tests. It's not uncommon to see polar bears near the area's southern coasts, where they regularly converge in winter for seasonal seal hunts, according to Russia's state-run news site TASS. [The Frozen North: Stunning Images of Russia from Above]

However, thinning sea ice caused by global warming likely drove the bears inland in search of more readily available meals, researchers from Moscow's A.N. Severtsov Institute of Ecology and Evolution, a branch of the Russian Academy of Sciences, told TASS. The allure of edible waste in Belushya Guba's garbage bins and dump sites likely stopped the bears from migrating farther north, the researchers said.

But dumpster diving isn't all the beasts are doing. Photos and videos posted over the weekend show the bears traipsing through empty schoolyards and even infiltrating the corridors of office buildings in search of food.

To protect the town, locals have built extra fences around schools and other sites, while special patrols try to scare off the bears with cars and dogs. These measures have shown "no tangible results" in spooking the bears and a special task force of "experts" is en route to assess the worrisome situation, TASS reported

Shooting or killing polar bears is prohibited by the Russian government — however, culling the most aggressive bears might become "the only and necessary measure to ensure safety" in Belushya Guba if an alternative isn't found quickly, the government statement said.

The bears, meanwhile, are enduring a crisis of their own. Polar bears are considered a vulnerable species around the world as global warming continues to diminish their sea ice habitats. In the Arctic, where the world's estimated 22,000 to 33,000 polar bears live, average temperatures are warming twice as fast as the rest of the world, resulting in huge declines in sea ice every year, according to a December 2018 report released by the National Oceanographic and Atmospheric Administration (NOAA).

As sea ice melts, polar bears have to travel farther and work harder to catch seals, causing some to starve to death in the process. Others — like those that crashed Belushya Guba — would rather eat garbage, it seems.

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Originally published on Live Science.

Last year was so hot that global land- and ocean-surface temperatures were 1.42 degrees Fahrenheit (0.79 degrees Celsius) above the 20th-century average, NOAA reported. Since 1880, when record-keeping began, only three years — 2016 (the highest, in part because of El Niño), 2015 and 2017 — were hotter.

"The key message is that the planet is warming," Gavin Schmidt, the director of NASA's Goddard Institute for Space Studies in New York City, told reporters at a news conference. "And our understanding of why those trends are occurring is also very robust. It's because of the greenhouse gases that we['ve] put into the atmosphere over the last 100 years." [6 Unexpected Effects of Climate Change]

The trend isn't a new one. Nine of the 10 warmest winters have happened since 2005, and five of the warmest years on record happened within the last five years, or from 2014 to 2018.

Moreover, NASA and NOAA double-checked their work against the findings of other groups, including the United Kingdom's Met Office and the World Meteorological Organization, which also ranked 2018 as the fourth warmest year on record.

There was record warmth (land and ocean temperatures) in much of Europe, the Mediterranean, the Middle East, New Zealand and Russia, as well as in parts of the Atlantic and western Pacific oceans, Deke Arndt, chief of the monitoring section at NOAA's National Centers for Environmental Information in Asheville, North Carolina, told reporters.

But it wasn't sizzling everywhere. "The interior part of northern North America was on the cool side of recent history, particularly the prairie provinces of Canada," Arndt said. That explains, in part, why 2018 was only among the top 20 warmest years for North America, he said.

Overall, the world over, both land and seas were hotter than average: The land was about 2.02 F (1.12 C) and the oceans were 1.19 F (0.66 C) warmer than the 20th-century average, NOAA found.

The area most impacted by climate change is the Arctic, which is warming between two and three times faster than the global average, Schmidt said.

"We obviously are very concerned with what's going on in the Arctic," Schmidt said. "We have a large decrease in Arctic sea ice, particularly in the summer and in September, which is the minimum sea-ice period in the Arctic. But there are also decreases in the winter as well, but they are less pronounced."

U.S. climate

In the United States, 2018 was the 14th warmest of the 124 years on record, at least for the contiguous 48 lower states, Arndt noted. It was about 1.5 F (0.83 C) warmer than the 20th-century average. As you can see in the map below, the dark red areas had the warmest years on record; the orange areas had temperatures in the top 10 percent of their history; and areas with light orange had temperatures that were in the warmest third of their history, Arndt said.

Last year was also the third wettest year in the U.S. on record, Arndt said. Hawaii even set a record for the rainiest 24-hour period in U.S. history, when it rained 49.69 inches (126 centimeters) in Kauai from April 14–15, 2018. [The Weirdest Things That Fell From the Sky]

Meanwhile, severe drought lingered in the Four Corners region of the American Southwest. While this area has experienced drought in the past, climate change has made these droughts more intense, largely because the soil dries out more due to increasing temperatures, Schmidt said.

Extreme climate events have also taken a toll on the U.S. economy. There were 14 weather- and climate-related events that cost more than $1 billion in 2018, making it the fourth largest total on record since 1980. (The scientists adjusted for inflation, Arndt noted.) In total, these events, including hurricanes Florence and Michael, as well as the wildfires out West, cost $91 billion in direct losses, Arndt said.

Double-checking data

Climate scientists have taken many precautions to expel uncertainties from their data. For instance, they factored in whether methodologies had changed over the years, Schmidt said. What's more, to avoid bias due to the so-called "urban heat island" effect, in which cities are warmer than surrounding areas, the agencies collect most of their data from rural areas; and if a station moves or the environment around it changes, scientists control for that, too, Schmidt said.

In addition, NASA satellites have been tracking climate data since 1979, which also serves as an outside check on data collected on Earth. These satellites show an indication that "the Arctic is warming more in the real world, according to satellite trends, than we are capturing in the station-based analysis," Schmidt said.

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Originally published on Live Science.

This morning (Feb. 2), a groundhog will not predict the weather.

Groundhogs (Marmota monax) are vegetarian, dirt-dwelling North American rodents the size of small dogs. In parts of the United States, tradition dictates that a particular groundhog has the power to predict the length of winter weather. If this year's Punxsutawney Phil (a name given to a groundhog in Punxsutawney, Pennsylvania) sees his shadow, the idea goes, there will be six more weeks of winter weather. If he doesn't see his shadow, spring will come early. Of course, neither Phil nor any other groundhog has weather-predicting powers. It's a fun thought though, isn't it?

Anyway, what will groundhogs not kept in captivity for the sake of odd secular holidays do if winter conditions persist into March? [6 Wild Ways the Moon Affects Animals]

The answer, it turns out, is pretty simple: Keep sleeping.

Groundhogs are deep hibernators, according to the SUNY College of Environmental Science and Forestry (ESF). They chow down before the chill, building up body fat, then enter winter burrows, lower their heart rates, and stop nearly all movement to make it through the cold, fallow months. During that period, their heartbeats drop from about 80 beats per minute to only four or five, and their body temperatures drop from 98 degrees Fahrenheit (37 degrees Celsius) to as low as 38 F (3 C).

One 1967 study published in the journal Ecology found that going without food, and not the cold, is actually the key factor triggering hibernation. Researchers found that groundhogs offered food would become active, even in chilly 42 F (6 C) temperatures, until the food ran out. But groundhogs deprived of their favorite snacks will go quickly into a torpor.

Not to worry though. Groundhogs are hardly little things. The researchers found that even though groundhogs in nature usually have to hibernate (alternating between more active states of "arousal" and "torpor") in their dens for only three or four months, under laboratory conditions a groundhog can hibernate for up to eight months.

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Originally published on Live Science.

Climate change is melting ice, intensifying storms and bleaching coral reefs, and now, a new study suggests that it could also take a toll on babies' hearts.

The study, published yesterday (Jan. 30) in the Journal of the American Heart Association, suggests that, starting in 2025, extreme heat brought on by climate change could increase the number of babies born with heart defects in the United States. The greatest increase would be seen in the Midwest, followed by the Northeast and the South, researchers reported.

Congenital heart defects, or heart abnormalities that infants are born with, affect around 40,000 newborns every year in the U.S., according to a statement from the American Heart Association. [7 Ways Pregnant Women Affect Babies]

It's unclear why a pregnant woman's heat exposure can lead to a congenital heart defect in a baby, but animal studies suggest that heat could cause cell death in fetuses and interact with heat-sensitive proteins that are important in development, according to the statement.

An earlier study from the same group of researchers found that women's exposure to high temperatures during pregnancy was linked to an increased risk of congenital heart defects in babies. The study included women who gave birth between 1997 and 2007.

In this new study, the researchers combine that data with climate change temperature projections.

The team built upon climate change forecasts gathered by NASA and the Goddard Institute for Space Studies. They simulated changes in daily maximum temperatures for various geographic regions in the U.S. and calculated how much heat and extreme heat events pregnant women would be exposed to in the spring and summer.

Between 2025 and 2035, they found that climate-change-driven heat events might spur an additional 7,000 cases of congenital heart defects, according to the statement. They found that most of these cases would be in the Midwest, followed by the Northeast and the South.

"Although this study is preliminary, it would be prudent for women in the early weeks of pregnancy to avoid heat extremes similar to the advice given to persons with cardiovascular and pulmonary disease during heart spells," senior author Dr. Shao Lin, an associate director of environmental health services with the University at Albany, State University of New York, said in the statement.

It's especially important for those planning to become pregnant or those who are three to eight weeks pregnant to avoid extreme heat, she said.

Live Science previously reported that pregnant women who are exposed to heat during early pregnancy can develop hyperthermia, or extremely high body temperature, which increases the risk of having babies with defects of the brain or spinal cord.

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Originally published on Live Science.

While the U.S. government was partially shut down for 35 days, the country's national parks suffered damage that could last generations. Now, as volunteers and conservationists assess the environmental and economic damage around the country, it seems that Joshua Tree National Park — a wonderland of spiky trees and surreal, time-sculpted rocks in Southern California — has experienced some of the worst damage.

"What's happened to our park in the last 34 days is irreparable for the next 200 to 300 years," Curt Sauer, a former superintendent of the park, said at a rally on Saturday (Jan. 26).

However, that estimate might be a bit overstated, according to one expert Live Science spoke to. While it's true that the survival of the park's Joshua trees has downstream impacts on the desert birds, insects, mammals and reptiles that rely on them for shelter and sustenance, the loss of a few individual trees is unlikely to have long-lasting effects on the park's 800,000-acre (324,000 hectares) ecosystem, Cameron Barrows, an associate research ecologist at the University of California Riverside's Center for Conservation Biology, told Live Science in an email.

Short shutdown, long-term damage

Reduced to a handful of essential staff during the shutdown, the park was unable to perform basic maintenance functions like emptying the trash or making sure the toilets didn't overflow with human waste. Meanwhile, only eight law-enforcement rangers were tasked with protecting the entire park's 1,238-square- mile-grounds (3,207 square kilometers) grounds — an expanse of land about the size of Delaware, Live Science previously reported.

During that time the security lapse, park gates were toppled and locks smashed. Rocks were defaced with graffiti, illegal campfires and vehicle traffic destroyed vegetation at some of the park's most iconic sites, and at least three of the park's ancient Joshua trees were chopped down in order to make way for illegal off-road paths. According to the National Park Service website, the average joshua tree in the park is age of the park's iconic trees is estimated to be about 150 years old.

But that doesn't necessarily mean damage to the park will take centuries to repair, Barrows said.

"Certainly, replacing one destroyed Joshua tree to the same age and condition could take [centuries]," Barrows said. "But I would be hard pressed to say the park is at greater risk of ecological damage by the loss of one tree. If it was, say, 100 acres or greater, then we are probably at a scale where ecosystem integrity is compromised." (Barrows noted that he has not been back to the park since the shutdown to see the full scale of the damage.)

More harmful to the ecosystem may be the many miles of fresh tire marks pummeled into the park's soil by off-road vehicles. That desert soil isn't just dirt or sand — it's also a complex community of vegetation and microbes that can help support every plant and animal that interacts with it.

"Vehicles creating improvised roads are a significant issue," Marinna Wagner, Masters in Landscape Architecture, told Live Science in an email. "Not only does such activity destroy existing vegetation, but the resultant soil compaction reduces soil moisture, increases runoff, causes erosion and sedimentation, and prevents seedling germination, thus slowing down the rate of ecosystem recovery even further."

National Park Service spokesperson Mike Litterst told Vice.com that soil damage like this can last for decades. So far, crews have helped repair about 20 miles (32 km) of tire tracks left during the shutdown, Vice reported, with many more to go.

These and other repairs may stress the park financially as it reckons with considerable financial losses from the shutdown. According to Sauer, the park relied on more than $300,000 in entrance fees to stay open during the shutdown, dipping into money that was meant to be used on park maintenance and the construction of a new visitors' center. In total, Sauer estimated that Joshua Tree lost about $800,000 in revenue during the shutdown.

Editor’s Note: This story was updated to add comment from Marinna Wagner.

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Originally published on Live Science.

Once vibrantly colored and teeming with life, many coral reefs around the planet are now bleached and barren, thanks to a condition called coral bleaching. Their color drained, bleached reefs stand like skeletons along the world's coastlines, from Australia and Madagascar to the Persian Gulf and the Caribbean Sea.

But coral bleaching is much more than an aesthetic loss. It is an environmental indicator: an omen of starving animals, a failing ocean ecosystem and a devastating change in global climate. Rising ocean temperatures are the fundamental cause. But before we can understand why these beautiful coral ecosystems are now at risk, we have to understand how they got their radiant color in the first place.

How do corals get their color?

Coral reefs are made up of polyps, small, colorless animals that have a sac-like body with a mouth-like opening and a crown of stinging tentacles. A coral reef consists of many individual polyps functioning together as one unit.

The polyps themselves are transparent. Coral reefs get their color from the tiny creatures living inside the polyps: algae called zooxanthellae.

Coral and zooxanthellae enjoy a mutually beneficial partnership, known as symbiosis. Coral provides the algae with shelter, access to sunlight and other resources needed for photosynthesis. The algae, in turn, share the nutrients produced by photosynthesis with the coral. As much as 90 percent of the nutrients that algae produce are transferred to their coral hosts, according to the National Oceanic and Atmospheric Administration (NOAA).

Why do corals bleach?

Under environmental stress, the intricate algae-coral partnership becomes unhinged. Factors such as temperature changes, pollution and overfishing can destabilize the relationship and cause the coral to expel the algae. Once the algae are gone, the coral's bright white calcium-carbonate exoskeleton is visible through its transparent tissue, hence the name coral bleaching.

Rising sea temperatures brought on by global warming have become the greatest danger to coral reefs, according to NOAA. Temperature spikes of only 1.8 to 3.6 degrees Fahrenheit (1-2 degrees Celsius) can trigger mass bleaching events that affect tens to hundreds of miles of coral reef. This type of heat stress affected 70 percent of the world's coral reefs between 2014 and 2017.

Coral bleaching happens gradually, said Ruben Torres, a marine scientist and the founder of Reef Check Dominican Republic, a nonprofit ocean-conservation group. As water temperature rises above the coral's comfort zone, the algae begin to leave, and the coral grows paler until all of the algae are gone.

"Once algae are gone, they [the corals] lose their source of energy," Torres said. "They are basically starving to death."

Bleached coral are still alive, but without the algae, the coral are vulnerable. They have less energy and are more prone to disease. If the water temperature remains high for days or weeks, according to NOAA, bleached coral will begin to die. If the water temperature goes back to normal, the coral can eventually regain algae and their color, but even the fastest growing corals need 10 to 15 years to fully recover, according to a 2013 study published in the journal Science.

"We used to think bleaching happened once a century," said Dave Vaughan, a biologist at the Elizabeth Moore International Center for Coral Reef Research & Restoration in Florida. "Corals would have 100 years to recuperate," he said. "But then, there was one bleaching in the '70s, two in the '80s and now 12 in the last 14 years."

The rise in coral bleaching parallels increases in atmospheric and ocean temperatures. Between 2016 and 2017 — the two hottest years on record, according to NASA — half of the Great Barrier Reef died in bleaching events set off by high sea temperatures, a study published in 2018 in the journal Nature reported. [Image Gallery: Great Barrier Reef Through Time]

A sliver of hope

The outlook for corals is grim but not completely hopeless. Natural reefs will not last through the 21st century if climate change continues undeterred, according a 2017 United Nations assessment. Because plans for lowering global carbon dioxide emissions are not taking effect at a rate fast enough to save reefs, some scientists are going a step further to preserve coral communities by giving them a boost.

Vaughan and his colleagues explore coral reefs that have experienced bleaching to find the survivors. The researchers then raise those particular corals in the lab to better understand what makes them more resilient. Vaughan said he hopes to grow coral that can withstand today's conditions — and tomorrow's warmer conditions — and then plant them on natural reefs to make the reefs hardier.

"Some corals aren't affected or bounce back faster so they don't get disease or starve to death," Vaughan said. "If we make more of those, we make a more resilient reef."

Other researchers are busy crossbreeding different strains of resistant corals to develop what are known as supercorals, which have an even better chance at surviving climate change. Both types of resilient coral have been grown in nurseries and planted back in the ocean successfully, but only on an experimental level. Now, scientists are aiming to plant at a much larger scale, Vaughan said. Reef restoration is desperately needed all over the world, but it won't come cheap, he said.

The first few years of growing and planting coral have a high cost and a low output. It can cost $25 to $200 to grow and plant a single coral, Vaughan said. A reef the size of a football field contains upward of 10,000 individual corals; that's $2 million to restore a small reef.

After four to five years, however, production increases and the price per coral falls. Today, Vaughan's lab grows and plants each coral for $10, and he said, at scale, that number could fall to $2 per coral, each critter costing the same as a cup of coffee.

So, what's the cost of restoring the world's reefs? Vaughan has run the numbers (it's in the billions), but he said the better question is, "What's the cost if we don't?"

Are coral reefs really worth the trouble?

No matter how much these rescue attempts cost, marine biologists argue that saving coral reefs is essential, for both biological and economic reasons.

Coral reefs cover only 1 percent of the ocean floor, but the Smithsonian estimates that as much as 25 percent of marine life depends on these reefs for food and shelter. In other words, coral reefs make up the backbone of the ocean's most diverse ecosystem. So, although the term "coral bleaching" refers to a phenomenon affecting just one group of closely related species, their deaths devastate an entire habitat.

Humans also have a huge stake in healthy coral reefs. Reef-related tourism is worth $35 billion to the global economy, according to a 2017 study published in the journal Marine Policy.

Reefs also help to protect shorelines, especially with today's increasingly severe tropical storms, preventing as much as $4 billion in flood damages globally every year, according to a recent study in the journal Nature Communications. The demise of these reefs, via bleaching and collapse, would cost the U.S. $100 million a year in additional flood damages, the same study concluded. Countries like Indonesia and the Philippines would be hit even harder, incurring annual damages of more than $600 million.

Saving coral reefs is daunting, but the alternative is cataclysmic, Vaughan said. He's set his sights on planting 1 million corals before he retires. He's planted TKHOWMANY so far. Starting in January 2019, he's taking his reef-restoration efforts global through his Plant a Million Corals effort, in which he travels the world educating and consulting clients on how to restore the reefs near them. As Vaughan sees it, "There is hope."

Further reading:

• See these shocking images from the Coral Reef Image Bank of the devastating effects of coral bleaching.
• Read more about coral bleaching on the Great Barrier Reef, from the Australian Marine Conservation Society.
• Find an overview of the basic biology of coral reefs here from the Scripps Institution of Oceanography.

There's a giant void hiding under the Antarctic ice, and it's growing larger and more menacing by the day, a new study using satellite data finds.

The cavity is colossal, about two-thirds the area of Manhattan and nearly 1,000 feet (300 meters) tall. It's growing at the bottom of Thwaites Glacier in West Antarctica, and it's rapidly enabling ice melt above it.

Scientists thought there might be some gaps between Thwaites Glacier and the bedrock below it, where ocean water could flow in and melt the icy glacier above it. But even they found the immensity and speed of the void's growth surprising. [Top 10 Ways to Destroy Earth]

For starters, the void is large enough to have once held 15 billion tons (13.6 billion metric tons) of ice, but much of that ice has melted during the past three years, according to NASA.

"We have suspected for years that Thwaites was not tightly attached to the bedrock beneath it," study co-researcher Eric Rignot, a professor of Earth system science at the University of California, Irvine, and a principal scientist for the Radar Science and Engineering Section at NASA's Jet Propulsion Laboratory in Pasadena, California, said in a statement.

Scientists spotted the concealed void thanks to a new generation of satellites, Rignot noted. These satellites, which are part of NASA's Operation IceBridge, have ice-penetrating radar. The researchers also used data from a constellation of Italian and German spacecraft that are equipped with an SAR (synthetic-aperture radar) instrument that can measure how ground surface has shifted between images.

These tools revealed that the ground had shifted substantially from 1992 to 2017, the scientists found.

"[The size of] a cavity under a glacier plays an important role in melting," study lead researcher Pietro Milillo, a scientist at the Radar Science and Engineering Section at JPL, said in the statement. "As more heat and water get under the glacier, it melts faster."

Thwaites Glacier is about the size of Florida and currently responsible for roughly 4 percent of global sea rise. If the entire glacier melted, the resulting water could raise world ocean levels by more than 2 feet (65 centimeters), the researchers said. Moreover, the glacier acts as a backstop for neighboring glaciers, meaning that it slows the rate at which they lose ice. If those glaciers melted, too, sea levels could increase a whopping 8 feet (2.4 meters), the research team said.

Although Thwaites Glacier is one of the hardest places on Earth to reach, more of its secrets will soon be revealed. This summer, the U.S. National Science Foundation and the British Natural Environmental Research Council are launching the International Thwaites Glacier Collaboration, a five-year field project that aims to get to the bottom of the glacier's processes and features.

Uneven retreat

Thwaites Glacier, curiously, isn't melting in a uniform way.

"We are discovering different mechanisms of retreat," Milillo said. For instance, the 100-mile-long (160 kilometers) glacier front has different rates of retreat in its grounding line (where the sea ice meets the ocean's bedrock) depending on where you look. [In Images: IceBridge Investigates Antarctica]

The satellites revealed that the enormous void is hiding under the glacier's western side, the one farther away from the West Antarctic Peninsula, the researchers said. In essence, this means that the glacier at this spot is exposed to the ebb and flow of the tide, which causes the ice at the grounding line to retreat and advance across a region that's about 2 to 3 miles (3 to 5 km) long.

However, there's been more retreat than advancement as of late. The glacier has retreated at a steady rate of about 0.4 to 0.5 miles (0.6 to 0.8 km) annually since 1992, the researchers found. This has made the melt rate on this part of the glacier unsettlingly high, the researchers said.

Meanwhile, "on the eastern side of the glacier, the grounding-line retreat proceeds through small channels, maybe a kilometer [0.6 miles] wide, like fingers reaching beneath the glacier to melt it from below," Milillo said. Here, the retreat rate of the ground line has doubled from about 0.4 miles (0.6 km) annually from 1992 to 2011 to 0.8 miles (1.2 km) a year from 2011 to 2017, he said.

Despite this high rate of retreat, melt rates are still higher on the western side, where the void is located.

These findings show the complexity of ice-ocean interactions. Hopefully, the upcoming international collaboration will help researchers piece together the different systems at work under and around the glacier, the researchers said.

"Understanding the details of how the ocean melts away this glacier is essential to project[ing] its impact on sea level rise in the coming decades," Rignot said.

The study was published online yesterday (Jan. 30) in the journal Science Advances.

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Originally published on Live Science.