The deadly heat gripping the U.S. Southwest and Southern Europe is only possible because of the changes our emissions have made to the climate, early research on this year's extreme summer shows.
A team of international researchers at World Weather Attribution tracked the effects of human-induced climate change on simultaneous heat waves across three continents.
They found that heat waves of this intensity could not have happened without the current levels of greenhouse gases in the air. The high temperatures encountered in the U.S. and in Europe would be "virtually impossible" without human-driven warming.
These gases drove the heat wave in Europe to be as much as 4.5 degrees Fahrenheit hotter, and made the one in the Southern U.S. and Mexico as much as 3.6 degrees hotter.
The prolonged US heatwave continues to set uncomfortable records
Forecasters say heat dome effects aren't going anywhere this week. Meanwhile, extreme heat is expected to affect the Midwest and East Coast.
The research found extreme heat waves like these are also becoming more common.
The world is now hot enough that heat waves like those scorching Arizona and Greece can be expected to happen every 15 years or so — and the warmer global temperatures get, the frequency of such heat waves is expected to increase.
Computer modeling — plus years of climate data to draw on — is making it possible for scientists to draw such conclusions much faster. The researchers at World Weather Attribution crunched this data in less than a week, regarding heat events that are still ongoing around the world. Because the data is so new, the findings have not yet been peer-reviewed.
