At least 499 U.S. counties have seen above-average temperature increases over the past century

Change in average temperature from 1895 to 2021
Map by The Guardian; click the image to enlarge it or click here for the interactive version.

"More than a third of the American population is currently experiencing rapid, above-average rates of temperature increase, with 499 counties already breaching 1.5C (2.7F) of heating," Oliver Milman reports for The Guardian. "The U.S. as a whole has heated up over the past century due to the release of planet-warming gases from burning fossil fuels, and swathes of the US west, northeast and upper midwest – representing more than 124.6 million people – have recorded soaring increases since federal government temperature records began in 1895."

A temperature increase beyond the 2.7F threshold matters because climate scientists say that, if the global average temperature increases beyond that, the resulting change in climate will cause increasingly catastrophic weather that will usher in widespread societal upheaval, Milman reports. As part of the 2015 Paris climate accords, most governments agreed to try to mitigate climate change to avoid such a rise in temperature.