Top 10 Craziest Solutions to Global Warming

World politicians will toss around the best ideas they have to get us out of the climate change mess we're in when they meet at the U.N. Copenhagen summit next week. Many people have suggested novel ways to combat the water pollution, smog, mounds of trash and global warming facing Earth. Here are some of the wackier (or at least, wackier-sounding) solutions ever proposed to solve Earth's problems.

10. Ban Plastic Bags and Light Bulbs

It may sound like a rash decision, but San Francisco, China, Australia and more have all jumped on board. China wants to rid the country of "white pollution" -- the plastic bags that clog city streets and waterways. And Australia hopes to cut its greenhouse gas emissions and reduce household energy bills by phasing out sales of incandescent bulbs. Such measures have gained momentum lately with more governments considering taking measures against the wasteful bags and inefficient bulbs. But before you worry about how you'll carry your groceries or light your home, these measures promote alternatives: recyclable paper bags and reusable cloth ones and more efficient (and cost-saving) compact fluorescent bulbs.

9. Live in Trash

No, this doesn't mean you should stop putting your garbage out every week and start living in an ocean of food wrappers and tissues. Rather, an engineer at the University of Leeds in England has created a construction material out of waste (for example, recycled glass, sewage sludge, and incinerator ash). These "Bitublocks" keep litter out of the landfill and could be used to build houses. They also take less energy to make than concrete blocks, their inventor says. Other scientists have proposed using waste material from poultry farms, such as chicken feathers, to make more environmentally-friendly plastics.

8. Bury the Carbon

Since we have all this extra carbon dioxide building up in the atmosphere and warming the Earth, some scientists have proposed taking that excess gas and trapping it somewhere, perhaps underground in aquifers, coal seams or depleted oil and gas fields. (The method is already used to push up dregs from the latter.) To do this, carbon dioxide would have to be separated from plant emissions, compressed and injected into an underground tomb, where it could be kept for thousands of years. There are still questions of the costs involved in siphoning off carbon dioxide from plant gas streams though, and some environmental groups worry about the gas seeping out of the ground.

They're not just pets (or food for them) — worms can be made useful by putting them to work eating those bits of sandwich crust and apple cores from the garbage and turning them into compost. The compost can then be used in gardens and to plant houseplants. Los Angeles city employees have been keeping a plastic bin of the little wriggling creatures in their office to recycle their lunch leftovers. If you're not wild about keeping a worm farm in your kitchen, you could always compost the old-fashioned way with a bin in the backyard.

6. Fill the Air With Sulfur

Certain types of aerosols, or tiny particles suspended in the air, are thought to have an overall cooling effect on the atmosphere. These particles intercept some solar radiation and scatter it back into space. The cooling effect on the Earth's climate can be seen after a volcanic eruption, which can spew millions of tons of sulfur into the atmosphere. Some scientists have suggested that we mimic nature and inject a bunch of sulfur into the atmosphere to counteract global warming. One problem with this plan is the increased amount of acid rain this would generate. Another is that sulfur would have to be regularly injected into the atmosphere to keep up the cooling, or global warming would pick up right where it left off.

5. Plant Fake Trees

Engineers have proposed building a forest of 100,000 fake trees to soak up carbon emissions and combat global warming. The trees — machines really — would suck carbon from the air through filters and then store it. The prototype devices are about the same size as a shipping container, and could remove thousands of times more carbon dioxide from the atmosphere than an equivalent-sized real tree, say scientists from the Institution of Mechanical Engineers. The technology still needs work, though, as does the infrastructure to store the trapped carbon.

4. Grow Algae in the Ocean

Environmentalist and futurologist James Lovelock, creator of the Gaia hypothesis, recently added a scheme of his own to the somewhat zany list of proposed global warming remedies. Lovelock's idea is to use pipes to stimulate mixing in the world's oceans, bringing deep, nutrient-rich waters to the surface to feed huge algae blooms that would suck up carbon dioxide from the atmosphere and sink it to the bottom of the ocean as they died. This method would only be a Band-Aid though, Lovelock says, because warming will continue for some time, even if we stop emitting greenhouse gases today.

3. Lengthen Airplane Flights

Besides using up fuel and emitting carbon dioxide exhaust, airplanes also harm the environment by creating artificial contrail clouds of condensed water vapor in their wakes. The clouds act as atmospheric insulation, trapping heat underneath them on the planet. To combat the problem, some scientists have proposed requiring planes to fly at lower altitudes, where contrails are less likely to form. But to fly lower, planes would have to travel longer to reach their destinations. This would also use up more fuel, but advocates say the drop in fuel efficiency would be offset by the gain in reducing contrails. Plus, aircraft engineers could focus on making planes more fuel-efficient at lower altitudes.

2. Give the Ocean a Dose of Iron

Here's the basic idea: Tiny photosynthesizing plankton in the ocean use carbon dioxide from the air to make food. When they die, they sink down to the ocean floor, taking the carbon with them. Because iron stimulates phytoplankton growth, some people have suggesting fertilizing parts of the ocean with iron to create huge plankton blooms to suck up some of the excess carbon dioxide we've emitted into the atmosphere. Several private companies have attempted ventures to dump iron into the ocean to sell carbon credits, but many scientists question just how effective the massive blooms are at trapping and storing carbon. Environmental groups have also warned that iron dumps may harm the local marine ecosystems.

1. Build Earth Some Sunglasses

When you're lounging on the beach on a sunny day with the sun's hot rays beating down on you, you may try to keep out the glare with a pair of sunglasses or a hat. Some scientists have proposed taking a similar strategy with our warming planet: putting a ring of sunlight-scattering particles or micro-spacecraft in orbit around the equator. The idea is that the ring would reduce the amount of solar radiation hitting the planet and counteract some of the warming induced by greenhouse gases. The wild idea would also be an expensive one, with a potential price tag of trillions of dollars.

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