The health and well-being of Americans are already affected by climate change, with the adverse health consequences projected to worsen with additional climate change. Climate change affects human health by altering exposures to floods, droughts, and other extreme events; vector, food, and waterborne infectious diseases; changes in the quality and safety of air, food, and water; and stresses to mental health and well-being.

Source: Chapter 14 of the Fourth National Climate Assessment



Maps show the incidence of West Nile neuroinvasive disease in the United States for 2010 through 2013. Shown as cases per 100,000 people {Data available from CDC 2015, Figure provided by Micah Hahn}.

Human health has always been influenced by climate and weather. Changes in climate and climate variability, particularly changes in weather extremes, affect the environment that provides us with clean air, food, water, shelter, and security. Climate change, together with other natural and human-made health stressors, threatens human health and well-being in numerous ways. Some of these health impacts are already being experienced in the United States (Source: Chapter 1 of The Impacts of Climate Change on Human Health in the United States: A Scientific Assessment).

The influences of weather and climate on human health are significant and varied. They range from the clear threats of temperature extremes and severe storms to connections that may seem less obvious. For example, weather and climate affect the survival, distribution, and behavior of mosquitoes, ticks, and rodents that carry diseases like West Nile virus or Lyme disease. Climate and weather can also affect water and food quality in particular areas, with implications for human health. In addition, the effects of global climate change on mental health and well-being are integral parts of the overall climate-related human health impact (Source: Chapter 1 of The Impacts of Climate Change on Human Health in the United States: A Scientific Assessment).

Individuals, communities, public health departments, healthcare facilities, organizations, and others are taking action to reduce health and social vulnerabilities to increase resilience to the risks projected in coming decades. Local efforts include altering urban design (for example, by using cool roofs, tree shades, and green walkways) and improving water management (for example, via desalination plants or watershed protection). These can provide health and social justice benefits, elicit neighborhood participation, and increase for specific populations, such as outdoor workers. Adaptation options at multiple scales are needed to prepare for and manage health risks in a changing climate. For example, options to manage heat-related mortality include individual acclimatization (the process of adjusting to higher temperatures) as well as protective measures, such as heat wave early warnings, air conditioning at home, cooling shelters, green space in the neighborhood, and resilient power grids to avoid power outages during events (Source: Chapter 14 of the Fourth National Climate Assessment).

Guiding Concepts
  1. In what ways does the changing climate affect public health where I live?
  2. What risk factors make individuals or communities more vulnerable to climate-related health effects?
  3. How can public health agencies, communities, and individuals plan for uncertain future conditions?
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Updated on April 21, 2021