The Health Impacts of Climate Change

Katrina Evacuee
Firefighters carry a Hurricane Katrina evacuee in August 2005 / Photo: FEMA


By now you’ve probably heard that climate change is causing more extreme weather events and impacting the economy. But did you know that our changing climate is also affecting well-being?

In 1990, the U.S. Congress passed a law requiring government agencies to report on the science and impacts of climate change every four years. This report, known as the National Climate Assessment, draws experts from around the country to present the latest climate research to Congress. The most recent assessment was released in 2014. What did that report say about the health impacts of climate change? Here’s a breakdown.

Climate change is intensifying…

Allergies: Warm winters lead to a greater prevalence of allergy-inducing pollen. In some parts of the U.S., pollen season has already lengthened by nearly a month since 1995. Increased rainfall and higher temperatures will also cause more indoor fungi and mold.

Wildfires: The country’s three worst wildfire seasons in terms of acreage burned have all occurred within the past decade.Scientists expect wildfires to get worse in years ahead. Many communities, even those as far as a thousand miles downwind, will have more smoke exposure and risk of asthma, bronchitis, respiratory infections and pulmonary disease.

Heat Waves: Extreme summer heat is increasing in the U.S. – 2016 was the hottest year on record, according to scientists. Rising summer temperatures lead to higher rates of cardiovascular and respiratory illnesses and heat stroke. Milder winters may reduce illness related to cold and snow, but they are not expected to offset the damage of hotter summers.

Extreme Weather: Some of the impacts from extreme weather are obvious: drowning by flash floods, for example. But illness is often a problem in the wake of major disasters like Hurricane Katrina. Waterlogged buildings breed mold, and unusually high and low precipitation can lead to diarrheal diseases. Mental illness is also widespread after major disasters.


Photo: NIH

Air Pollution: Summertime ozone pollution rises along with temperatures. Ozone exposure causes more lung problems like asthma and heart attacks. These ozone-related health costs have been estimated at $6.5 billion nationwide. Already, about 25% of emergency room visits are asthma-related.

Infectious Disease: The geographic distribution of some diseases is changing as the creatures that carry them move due to climate change. Milder winters are changing patterns of transmission for Lyme disease, dengue fever, West Nile virus, and more.

Food Insecurity: Changes in rainfall and temperature put our food supply at risk, according to the USDA and others. Many common crops are expected to face reduced yields and greater threat from weeds and pests, likely leading to increased use of toxic pesticides (and subsequent exposure on food and by farm workers). Rising food prices will affect people’s diets for the worse.  

Risk to Already Vulnerable Populations: The poor, the elderly, and children are most at risk from climate change’s health impacts. Limited accesses to resources makes it hard to recover from major weather events and many poor people already suffer from compromised health due to things like food insecurity and exposure to higher levels of pollution in their communities.

Luckily, by fighting the causes of climate change, we can also improve the health of our communities. Making sure that our cities are transit and pedestrian friendly not only reduces the greenhouse gas emissions we produce, but also keeps people active. Shutting down coal plants in vulnerable communities will reduce the prevalence of respiratory illnesses, and providing more green space counters the heat island effect while providing recreational opportunities and clean air for residents. After all, prevention works not only for individual health, but for climate change mitigation as well.

Want to get involved in shaping the future of our planet? Here's how you can do something about this issue and others that impact you and your family!