Human health could be impacted by climate change in a variety of ways. Warmer temperatures, changes in precipitation, and increases in extreme weather events can combine with other factors to affect the health of Wisconsin's citizens.

Potential Risks

Photo: Pine Cone

Adult Deer Tick
Photo by Scott Bauer, USDA

The potential impacts of climate change on health arise from a combination of human and environmental factors. The risks are not evenly distributed among our population; some groups are more vulnerable than others (the very young, the elderly, the economically disadvantaged, and those whose health is already compromised). Climate change projections suggest that nighttime temperatures will rise and the frequency of extreme rainstorms will increase. This means that air and water quality, extreme heat, and storm-related risks could increase for residents of Wisconsin. Among the concerns are:

  • Warmer nighttime temperatures might lead to more extreme heat waves, increasing the risk for heat stroke in some populations. At the same time, observed and projected trends show fewer cold temperature extremes, which may mean reduced health risks due to exposure in the winters.
  • Air pollution, increasing temperatures, changing circulation patterns, and other processes combine to increase ground-level ozone, which affects respiratory health.
  • Heavy rains and flooding can overwhelm sewer and stormwater systems, leading to a rise in water pollution and the risk of waterborne diseases such as cryptosporidium and giardia. An increase in extreme precipitation events is already being seen in Wisconsin.
  • Changes in temperatures and precipitation could result in an increase in disease-carrying insects, including ticks and mosquitoes. This means people may be at a greater risk for contracting vector-borne diseases, such as Lyme disease and West Nile encephalitis.

Back to top

Photo courtesy of the Milwaukee Metropolitan
Sewage District


The members of the Human Health Working Group come from the University of Wisconsin-Madison and the University of Wisconsin-Milwaukee.

  • Jonathan Patz (Chair) - Nelson Institute Center for Sustainability and the Global Environment (SAGE), UW-Madison
  • Kristen Malecki - Wisconsin Department of Health Services
  • Sandra McLellan, Great Lakes WATER Institute, UW-Milwaukee
  • Shelly Shaw - Wisconsin Department of Health Services
  • Steve Vavrus, Department of Atmospheric and Oceanic Sciences and Nelson Institute Center for Climate Change Research (CCR), UW-MadisonĀ 

Back to top


Please contact Jonathan Patz if you have any comments or concerns regarding Wisconsin's human health and our changing climate.