When I say, "how about that heat wave," perhaps you think of the western United States, where temperatures last week soared above 120 degrees Fahrenheit (49 degrees Celsius), smashing dozens of historical heat records from Oregon to Arizona.
Or maybe you think of India — where intense heat has scorched the country for more than a month, killing at least 36 people and forcing hundreds of thousands to evacuate their villages — or perhaps Kuwait, where local media recently reported high temperatures of 145 F (63 C), potentially the highest temperature ever recorded on Earth.
The point is, the Northern Hemisphere is really, really hot right now and summer has barely begun. If it seems like these record heat waves are happening more often, that's because they are — and, according to a new study published today (June 17) in the journal Nature Climate Change, this scorching trend will continue for most of the globe every single year as long as no action is taken to reduce greenhouse gas emissions. [The Reality of Climate Change: 10 Myths Busted]
In the new study, a team of Australian meteorologists analyzed the predictions in 22 separate climate reports to calculate one range of überpredictions about our planet's hot, hot future. The scientists found that, under current levels of greenhouse gas emissions, high monthly temperature records will be set in approximately 58% of the world (including 67% of the poorest nations) every single year until 2100. Nearly 10% of the world will also have at least one monthly temperature record "smashed" by more than 1.8 F (1 C) every year.
That's one possible future. However, the researchers found, if the world's nations substantially reduce greenhouse gas emissions by 2020 (a scenario that the United Nations Intergovernmental Panel on Climate Change calls RCP2.6), the percentage of places on the planet setting new heat records every year drops to 14%.
"The impact of emissions reductions on the total number of monthly records set is stark," the authors wrote in the study.
For example, the team found, many nations near the equator can expect to see 24 monthly heat records surpassed every decade that emissions remain unchecked — in other words, roughly two months of every year will be hotter than in any year before it. Under the low-emissions model, that number drops to less than three records per decade.
"The benefits of reducing emissions, in terms of both reducing the pace at which high temperature records are set and restricting the magnitude by which records are broken, are very clear," the researchers wrote.
However, they cautioned, under the best-case scenario, it could still take decades for the rate of these monthly temperature extremes to start dropping. There's no way we're meeting that 2020 goal — but still, the sooner the world starts taking meaningful action against climate change, the better.
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Originally published on Live Science.
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Brandon is the space/physics editor at Live Science. His writing has appeared in The Washington Post, Reader's Digest, CBS.com, the Richard Dawkins Foundation website and other outlets. He holds a bachelor's degree in creative writing from the University of Arizona, with minors in journalism and media arts. He enjoys writing most about space, geoscience and the mysteries of the universe.