Killer summer heat: Paris Agreement compliance could avert hundreds of thousands of needless deaths in America's cities

This issue brief assesses the impact of climate change-induced extreme heatwaves on health in urban areas in the United States. It provides data on the number of heat-related illnesses and deaths in the country and estimates the number of deaths that would be averted if countries worldwide, including the U.S., honour commitments made to the 2015 Paris Agreement.

Projections of summertime deaths due to extreme heat were made based on the weather classification system Spatial Synoptic Classification, with U.S. Census Bureau data on urban areas. It finds that all 51 of America’s urban areas with populations of more than one million will experience considerably more dangerous summer days in the 2090s than they did from 1975 to 2010. In many areas, warming will be compounded by the urban heat island effect. It also finds an increase in excess deaths in all 45 of the urban areas with a statistically significant relationship between deaths and dangerous summer days.

In particular, the brief warns of the potential negative health impact of changes to the Environmental Protection Agency (EPA), lowered budgets affecting the Centers for Disease Control and Prevention (CDC), and a weakened Affordable Care Act and programs such as the Low Income Home Energy Assistance Program.