The Real Consequences of Climate Change on Our Health


Heart attacks, miscarriages, encephalitis, pneumonia… Some dedicated researchers are working hard to tie actual health outcomes to climate change events which are expected to only worsen and intensify if policy leaders do not change course.

Researchers from the University of California, San Francisco and the Natural Resources Defense Council set out to better understand how climate-sensitive events impact human health and the economy.

Based on an analysis of state and federal health data and peer-reviewed studies for 10 U.S. climate-sensitive events in 2012, the research team found they led to “an estimated 917 deaths, 20,568 hospitalizations, and 17,785 emergency department visits, along with other health-related expenses, totaling nearly $10 billion (in 2018 dollars) in health-related costs.” 1

To put this in a more current perspective, the recent US emergency Covid-19 spending package totals $8.3 billion. 2

The climate-sensitive events and associated illnesses were: 1

  • Colorado and Washington’s wildfires resulted in major respiratory illness including asthma, upper respiratory infection, pneumonia, bronchitis, and chronic obstructive pulmonary disease. Cardiovascular complications including heart attacks.
  • Nevada saw higher ozone air pollution during heatwaves that created smog which contributed to asthma, chronic lung disease, and other respiratory illness.
  • Wisconsin experienced extreme heat lasting over a week, which caused heat stress, heat stroke, and heat exhaustion.
  • Michigan saw increased tick‐borne Lyme disease which caused rashes, fevers, headaches, fatigue, and even meningitis.
  • Texas experienced mosquito‐borne West Nile virus where the highest rates of deaths nationally where reported. Illness included headache, body ache, joint pain, vomiting, diarrhea, encephalitis, meningitis, and rash.
  • Ohio experienced extreme weather in the form of heavy precipitation events that led to flooding and sewer overflows that contributed to gastrointestinal illness, acute respiratory infections, skin infections, and asthma.
  • Hurricane Sandy in New Jersey and New York caused multiple deaths, acute respiratory illness, carbon monoxide exposure, falls, fractures, homelessness, hypothermia, overexertion, mental or mood disorders, pregnancy complications, and a host of other illnesses.
  • North Carolina experienced high levels of allergenic oak pollen from warmer weather, higher humidity, and higher carbon dioxide which extended pollen production and led to increased asthma ED visits and deaths.
  • Florida had harmful algal blooms along the coast where ocean surface temperatures were high and seawater was more acidic, which contributed to respiratory, digestive, and neurologic illnesses.

Here is a video with one of the study authors, Kim Knowlton, senior scientist and deputy director of the Natural Resources Defense Council’s Science Center.


The study authors were interviewed for the blog of the American Geophysical Union. In answer to the question, “Where there any findings that surprised you?” They replied:

“We were struck by the many types of health problems linked to climate-sensitive events that extended way beyond what typically comes to mind when we think about the health risks posed by increasing global temperatures.

“Our research identified a whole host of illnesses, including pregnancy complications, carbon monoxide poisonings, and kidney disease complications, all linked to the aftermath of Hurricane Sandy in New Jersey and New York. And we doubt whether many people outside Florida realize the number of hospital admissions and emergency room visits there due to harmful algal blooms.

Based on what we know about the data, these examples also signal to us that there’s a whole host of other health problems that are likely hitting people right now, so we’ve got to urgently address the root problem of climate change to prevent widespread suffering on a level that we’ve never seen before.”3

Analytic work of the kind undertaken for this study will likely become increasingly critical in helping policymakers understand the human toll often lost in climate change statistics.


1Limaye VS, Max W, Constible J, Knowlton K. Estimating the Health-Related Costs of 10 Climate-Sensitive U.S. Events During 2012. GeoHealth 2019; 3(9):245-265.

2H.R.6074 – Coronavirus Preparedness and Response Supplemental Appropriations Act, 2020. 6 March 2020.

3Balbus J, Limaye V, Knowlton K. Putting a Price on the Costs of Climate Related Health Impacts. 9 October 2019. Eos, 100.

VIDEO: The Health Impacts of Climate Change. 29 March 2017. National Resources Defense Council.



Leave a Comment