How many more will die in US heatwaves as world warms?

Enlarge (credit: Garrett Ziegler / Flickr)

One of the more obvious risks of climate change is an increased frequency of extreme heatwaves. Particularly in cities, heatwaves can be more than sticky and unpleasant—they can be deadly.

The emissions cuts pledged so far in the international Paris Agreement in 2015—if followed through—would limit global warming to the neighborhood of 3°C. That won't prevent an increase in deaths due to heatwaves, but just how much worse is 3°C than the international goals of stopping warming at 2°C or event 1.5°C?

To find out, a team led by Eunice Lo at the University of Bristol analyzed the relationship between extreme summer temperatures and deaths for 15 US cities with data: Atlanta, Boston, Chicago, Dallas, Detroit, Houston, Los Angeles, Miami, New York City, Philadelphia, Phoenix, San Francisco, Seattle, St. Louis, and Washington DC.