The Issue

“Climate change is the biggest global health threat of the 21st century.”
—The Lancet Countdown on Health and Climate Change

Air Pollution

Climate change increases levels of major air pollutants including particulate matter, ground-level ozone, and pollen, which can induce or aggravate respiratory conditions such as allergies, asthma, chronic obstructive pulmonary disease, and lung cancer, as well as cardiovascular disease.

  • Particulate matter is released from industrial or vehicle emissions as well as forest fires, which are increasing in incidence due to climate change. Exposure to particulate matter has been linked to asthma, chronic bronchitis, reduced lung function, irregular heartbeat, heart attack, and premature death.
  • Ozone occurs naturally in the upper atmosphere but can also form at ground level when other air pollutants are exposed to heat and sunlight. Climate change increases temperatures and changes atmospheric circulation patterns, increasing ground-level ozone. Exposure to ozone can aggravate asthma and cause respiratory disease, and increases the risk of premature death from cardiovascular disease.
  • Climate change increases temperatures and shortens winters, increasing both the quantity and duration of pollen production. Pollen is an allergen and contributes to allergies, asthma, and other respiratory illnesses.

Extreme Heat

As average temperatures increase, extreme heat events are predicted to become more frequent, longer-lasting, and severe.

Minnesota and the Midwest as a whole will be particularly hard-hit. Summers in the Twin Cities now have around five more extremely hot and humid days and five fewer cool, dry days than in the mid-1940s.

Extreme heat events can:

  • exacerbate previously existing medical conditions such as diabetes, cardiovascular disease, chronic obstructive pulmonary disease, kidney ailments, and mental or behavioral disorders, and can cause direct health effects such as heat stress, heat stroke, and even death.
  • also impact infrastructure, causing power failures, disrupting social or occupation events, and strains emergency and health care services

Floods and Drought

Climate change is predicted to increase the frequency, intensity, and duration of extreme weather events including flooding and drought.

  • Direct health effects of flooding include injuries and death, and waterborne diseases. Floodwaters can carry toxic contaminants such as pesticides and fertilizers from agricultural runoff and pathogens and pharmaceuticals from sewer overflow that if introduced into drinking water can cause gastrointestinal illness or even death. Private wells are particularly vulnerable to contamination via floodwaters.
  • Flooding can result in significant indoor mold growth, and exposure can cause respiratory infections and asthma as well as eye and skin irritation.
  • Arid conditions during drought can increase particulate matter air pollution, and drought can lead to food insecurity.
  • Both flooding and drought cause fiscal insecurity, loss of livelihood, and loss of community cohesion, and have significant adverse mental health impacts.

Vector-borne disease

Warmer, wetter conditions caused by climate change are favorable to the spread of insects harboring infectious pathogens.

  • Mosquito-borne West Nile virus is now endemic in every state in the U.S. and with 80 cases and three deaths in 2013, Minnesota is in the top 10 states with highest annual incidence.
  • Most cases have mild or no symptoms, but West Nile virus can cause encephalitis and even paralysis, coma or death in vulnerable individuals.
  • Lyme disease and other tick-borne diseases are also on the rise in Minnesota. In 2013 there were over 1,400 confirmed cases of Lyme disease.
  • Mild symptoms of Lyme disease include fever, headache, fatigue, and skin rash. If left untreated, the infection can spread to the joints, heart and nervous system, and may result in significant and irreversible damage.

Mental Health

According to a 2016 report by the U.S. Global Change Research Program, climate change impacts mental health and well-being, and those suffering from poor mental health are more susceptible to other negative health impacts of climate change.

  • Survivors of natural disasters experience stress and trauma and can develop depression, generalized anxiety, and post-traumatic stress disorder. Climate change increases the severity and frequency of extreme weather events.
  • The social and ecological consequences of climate change negatively impact mental health. Experiencing or anticipating ecological loss causes ecological grief, feelings of anger, hopelessness, despair, and a feeling of loss, and is linked to elevated rates of depression, anxiety, suicidal ideation, and post-traumatic stress disorder.
  • Mental illness increases the risk of poor physical and mental health due to extreme heat.


Minnesota Climate & Health Profile Report. Minnesota Department of Health. St. Paul, MN. February 2015.

Dodgen, D., D. Donato, N. Kelly, A. La Greca, J. Morganstein, J. Reser, J. Ruzek, S. Schweitzer, M.M. Shimamoto, K. Thigpen Tart, and R. Ursano, 2016: Ch. 8: Mental Health and Well-Being. The Impacts of Climate Change on Human Health in the United States: A Scientific Assessment. U.S. Global Change Research Program, Washington, DC, 217–246.

Cavanagh, Michaela. “It’s Time to Talk About Ecological Grief.” Undark, January 10, 2019.