This fact sheet highlights some of the impacts, threats, and vulnerabilities to human health in the United States associated with extreme weather events, examines how climate change is contributing to human health threats, and summarizes initiatives taking place to help address the issue.

Executive Summary

The impacts of climate change are adding to cumulative stressors that threaten human health. Climate-related threats to human health range from more frequent and intense extreme weather events, to reduced air and water quality, to increased risk of disease. Emerging evidence shows a warming climate contributes to more intense heat waves. Conditions leading to the 2011 Texas drought are 20 times more likely now, in a world warmed by greenhouse gas emissions, than in the 1960s. The warming climate has contributed to increasingly conducive conditions for longer-lasting wildfires and longer wildfire seasons in some regions, threatening communities and creating smoke that reduces air quality. Increasing extreme precipitation has amplified severe flooding in some locations, threatening human safety and water quality when the capacity of combined sewer and stormwater drainage systems is exceeded and sewage overflows from pipes and treatment plants into waterways. Warmer temperatures are lengthening allergy seasons in some places, causing distress to those with respiratory problems.