The U.S. is experiencing some of its hottest temperatures ever, and scientists say worse is to come
A heat wave that swept the United States last week set numerous single-day and weeklong records in states ranging from Arizona to Oklahoma to Illinois. According to CNN, Ninety percent of Americans experienced temperatures above 90ºF in a seven-day period. Over 1,200 heat records were set.
Only the perennially rain-soaked Northwest seemed to escape the heat unscathed, one exception being Portland, which will reached the low 90’s—well above average for the region.
If it feels like the summer months have been getting hotter each year, it’s because they have. In a 2019 study, scientists used previous heat index data to predict how temperature will change in the coming years. They found that, not only will the frequency and intensity of high-temperature days increase, it may render the heat index itself obsolete. Worse, the data points to that trend continuing throughout this century if emissions remain constant.
According to the study, by the mid-century mark “more than 25% of the US by area would experience no analog conditions an average of once or more annually and the mean duration of the longest extreme heat index event in an average year would be approximately double that of the historical baseline.”
While heat and humidity can be dangerous on their own—killing an average of 653 Americans each year according to the CDC—heat can cause many other problems. For example, as temperatures rise in dry areas like the southwestern United States (Death Valley, California, reached a sweltering 128ºF Sunday) the frequency of devastating fires also increases, an effect seen earlier this month when a heatwave in Siberia caused an outbreak of wildfires throughout eastern Russia.
As shocking as the record-breaking temperatures were, they may soon be surpassed. A study published in Nature Climate Change last summer claimed that by the end of the twenty-first century, “high monthly mean temperature records will be set in approximately 58% of the world every year, and in 67% of least developed countries and 68% of small island developing states.”
This heat wave won’t be the last, and if human-caused climate change continues, extreme summer scorchers may become the new normal.