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The health costs of climate change

The downtown skyline is enveloped in smog shortly before sunset on in Los Angeles, California. File photo.
The downtown skyline is enveloped in smog shortly before sunset on in Los Angeles, California. File photo.
David Livingston/Getty Images for NAMM

How much could climate change cost us in health care? According to a new study, more than $14 billion. 

The study is the first in the U.S. to look at estimated health costs from events that are projected to worsen and become more frequent with climate change – ozone pollution, heat waves, hurricanes, infectious disease outbreaks, river flooding and wildfires. The paper was published in Health Affairs and conducted by Natural Resources Defense Council scientists.

Researchers looked at six case studies of climate-related events that occurred in the US over the past decade to find the average cost of hospital visits, premature deaths, injuries and other health-related costs. 

While the damage climate change could do has been estimated, it has not been specific enough to inform public health policy. The final $14 billion health-related cost estimate is a conservative one and much lower than the actual cost would likely be. If a disaster strikes in one area, that doesn't prevent another one from occurring across the country. The U.S. is likely to suffer more than one of these events each year, Kim Knowlton, corresponding author and a senior scientist in the Health and Environment Program at the NRDC, told Sharon Begley of onearth.

Data from federal and state agencies and peer-reviewed journals was used to estimate the health-related cost of each event. Most of this cost is associated with premature deaths, with $740 million in actual health care costs. In total, there were 1,689 premature deaths, 8,992 hospitalizations, 21,113 ER visits and 734,398 outpatient visits from the six incidents.

In addition to reducing carbon emissions, the researchers recommend additional research and analysis of health-related costs, and with that, better monitoring of climate change-related events, and improved community preparedness strategies.

Ozone pollution

Ozone formation increases with the temperature. It affects lung function and inflames the airwaves, especially among young children, the elderly and those with respiratory illness, increasing ER visits, hospitalization and premature death. With data from a 2000-2002 study, Knowlton's paper calculates the pollution cost an estimated $6.5. billion in health care and premature deaths.

Heat waves

The frequency and intensity of heat waves is expected to increase, and higher temperatures put more stress on organs including the heart, lungs and kidneys. The estimated cost of a 2006 California heat wave recorded over two weeks was $5.4 billion. Ozone pollution and heat waves have the highest health costs due to mortality rates and the large number of people affected.


Climate change is expected to increase the wind speeds and rainfall during hurricanes as North Atlantic temperatures rise. Hurricanes result in drownings, carbon monoxide poisoning from power failures, psychological damage, and disease from contaminated water. In 2004, Florida experienced four intense hurricanes in one month, which cost $1.4 billion just in carbon monoxide poisoning. 

Infectious disease

With changing temperatures and habitats, the range and severity of infectious diseases outbreaks may worsen with climate change, especially in northern climates that support mosquitos. A 2002 outbreak of West Nile Virus in Louisiana cost $207 million for 24 premature deaths, 204 hospitalizations, and close to 5,800 outpatient visits.


The 2003 Southern California wildfires burned 736,000 acres and resulted in 69 deaths, 778 hospitalizations, and more than 47,600 outpatient visits, costing more than $578 million. California is expected to have a 21 percent increase in large fires between 2005 and 2034 and an 84 percent increase by the end of the century due to higher temperatures and drier regions. In addition to geographic destruction, wildfires cause severe respiratory and cardiovascular problems.

River flooding

The 2009 Red River flooding in North Dakota cost $20.4 million in health-related costs from psychological and physical injuries, and deaths. Higher temperatures will bring more rain and may cause more frequent river flooding across the nation.