Human Health Working Group

Climate impacts pose regional and local health risks in Wisconsin and will severely impact at-risk populations by causing death from illness, extreme heat, floods, impaired air quality, the spread of disease, or increased exposure to pollution.

The health impacts of climate change are not felt equally by all. Groups more at-risk include communities of color, children and pregnant women, the elderly, immigrant groups, Tribal nations, certain occupational groups, lower income households, and persons living with disabilities or chronic diseases.

When considering climate policy to protect the health of Wisconsin communities, it is imperative that strategies address historical injustices and not exacerbate already existing health equity issues.

Extreme Precipitation Events

Extreme precipitation events have markedly increased in Wisconsin over the last decade. These events are projected to become more frequent by mid-century as a result of climate change, with very extreme rainfalls seeing the largest change. The health impacts of flooding are numerous and include injuries, carbon monoxide poisoning, and drowning.

Flood events can produce increases in bacterial and viral infections and waterborne outbreaks among customers of municipal drinking water systems and recreational users of lakes and rivers. Contamination of surface water with phosphorous and nitrogen may lead to blooms of toxin-producing blue-green algae that can pose a risk to residents, visitors, and their pets.

Extreme Heat

Average annual temperatures in Wisconsin could increase by 2.5–7.5 degrees Fahrenheit by 2055. Extreme heat is associated with increased morbidity and mortality. Certain populations, especially the elderly and socially isolated individuals, are at increased risk of heat-related death. Air quality degradation due to heat may lead to respiratory distress, and additional airborne pollen may lead to increased asthma exacerbations and other allergic episodes.

Impaired Air Quality

Rising temperatures and changing climatic conditions in Wisconsin are expected to create conditions favorable for the creation of air pollutants and seasonal increases in pollen that adversely affect health.

Ground-Level Ozone

Climate change creates conditions, including heat and stagnant air, which increases the risk of unhealthy ozone levels forming. High ozone levels affect people with lung diseases, children, older adults, persons who work outdoors, and other at-risk populations by causing immediate breathing problems, cardiovascular harm, and premature death.

Particulate Matter

Hotter temperatures and lack of rainfall increase the risk of drought, dust storms, and wildfires, all of which create particle pollution. Larger particles can irritate eyes, nose and throats, and fine particles can get deep into parts of people’s lungs or even in the bloodstream, causing trouble breathing, lung cancer, low birth weight, heart problems, and premature death. People with heart or lung diseases, children, and older adults are the most likely to be affected by particle pollution exposure.

Pollen and Allergens

The increased length and severity of the pollen season is leading to potential health consequences for those already affected by allergies and asthma. The increasing amount of pollen may have a greater effect on children, who tend to be more vulnerable to ambient pollen. Moisture from increased rainfall and floods can also lead to increased mold growth that worsens allergies and causes asthma exacerbations.

Disease Vectors

A warmer, wetter climate could create more favorable conditions from human cases of West Nile virus, carried by mosquitoes, and Lyme disease carried by deer ticks. Changing environmental conditions may also support new mosquito-borne diseases in Wisconsin, and a northward shift in the range of the lone star tick and associated tick borne diseases into Wisconsin.

Whether a changing climate in Wisconsin will increase the chances of domestically acquiring diseases is uncertain due to vector-control efforts and lifestyle factors, such as time spent indoors, that reduce human-insect contact. Infectious disease transmission is sensitive to local, small-scale differences in weather, human modification of the landscape, the diversity of animal hosts, and human behavior that affects vector-human contact, among other factors.

Finer-scale, long-term studies are needed to help quantify the relationships among weather variables, vector range, and vector-borne pathogen occurrence; the consequences of shifting distributions of vectors and pathogens; and the impacts on human behavior.

The health impacts of climate change are not felt equally by all. Groups more at risk include communities of color, children and pregnant women, the elderly, immigrant groups, Tribal nations, certain occupational groups, lower-income households, and people living with disabilities or chronic diseases.

The health disparities experienced from climate change are environmental and climate justice issues. The Human Health Working Group is exploring many ways in which environmental and climate injustices harm people’s health, including:

• Heat-related illnesses and deaths will be felt disproportionately by communities located in heat islands. A 2020 analysis of U.S. cities found that discriminatory housing and planning policies played a significant role in how heat islands occur in predominantly low-income and communities of color. The heat island effect is often compounded in low income communities with poor housing conditions and lack of air conditioning.
• Formerly “redlined” areas are at greater risk from flooding compared to non-redlined areas.
• A warmer and wetter climate can stress food production processes across the state. Rural counties in Wisconsin often have less resources to combat food insecurity as a result of climate change. Food insecurity is associated with high blood pressure, diabetes, high cholesterol, heart disease, obesity, and mental health disorders.

Health policy changes need to include opportunities for the communities most impacted by climate change. Policy and planning change should happen on the local level and include health equity and resiliency principles during the planning and implementation process. The Human Health Working Group calls on decision-makers to consider mitigating these disproportionate impacts with improved climate action planning efforts.