These are the only two options left, according to a group of researchers who reviewed over 30.000 publications related to heatwaves…
The study, coordinated by the University of Hawaii at Manoa, focused on 911 papers with data on 1,949 case studies where human deaths were linked to high temperatures and discovered a common threshold beyond which temperatures and humidities became lethal.
Today, summers in Milwaukee and in Dallas are already respectively 1.34 and 1.6 degrees Celsius hotter on average, and 2.1 degrees Celsius in Salt Lake City. Even with reductions in emissions, one in two people at the end of the century will likely face at least 20 days when extreme heat can kill, according to an analysis published in Nature Climate Change.
For example, by 2100 New York is projected to have around 50 days with temperatures and humidities exceeding the threshold in which people have previously died. That same year, the number of deadly days for Sydney will be 20, 30 for Los Angeles, and the entire summer for Orlando and Houston.