A New Study Measures Extreme Heat's Human Impact, Flags At-Risk States

"The motley drivers of heat and cold exposure in 21st century US cities," a paper published by the Proceedings of the National Academy of Sciences (PNAS), reports on the findings of a new study about human exposure to extreme heat. 

To humanize the research, the study reports impact in terms of person-hours: the number of hours of intense exposure experienced by humans. 

"Overall, the researchers found that the average annual heat exposure at the start of this century in the United States was about 5.2 billion person-hours. They calculated that assuming a worst-case scenario of peak global warming, population growth and urban development, the annual heat exposure would rise to 150 billion person-hours by the end of the century, a nearly 30-fold increase," writes Sarah Wray. 

The Arizona State University researchers responsible for the study make use of a climate change modeling approach to better understand the influence of climate change on cities. In the United States, sunbelt cities were found to be the worst affected cities.

Wray's article summarizes the key takeaways from the research and makes suggestions about how cities can increase their resiliency in the face of climate change. Wray also notes that the researchers are working on a followup paper to communicate "city-specific estimates of the avoided heat exposure derived from urban adaptation measures and greenhouse mitigation."