Smoke From Wildfires Caused by Climate Change Will Fuel Many More Premature Deaths in the U.S., a New Study Warns

This would represent some of the country’s most costly consequences of a warming climate by mid-century, researchers say.

Smoke from wildfires exacerbated by climate change may cause as many as 71,000 additional deaths per year in the United States by 2050, a study published Thursday in the journal Nature found.

That would represent a 73 percent rise in premature deaths from those currently attributed to smoke from wildfires.

The health impacts of climate-driven wildfire smoke would be among the most critical and costly consequences of a warming climate in the U.S. by mid-century, the study’s authors concluded.

“Growing wildfire smoke is a much larger health risk than we might have understood previously,” said Marshall Burke, an associate professor of global environmental policy at Stanford University and a co-author of the study.

Wildfire activity has increased significantly in recent decades, due in part to human-induced climate change. The current study analyzed monthly and annual fire emissions data from 2001 to 2021 to predict future emissions from wildfires under different climate scenarios across North America.

A key focus of the analysis was emissions of PM2.5, fine particulate matter with a diameter of 2.5 microns or less, which can travel deep into the lungs and cause significant health damage. To estimate future deaths from wildfire smoke, the researchers paired recent premature deaths attributed to PM2.5 emissions with projections of increased fine particulate matter from future wildfires.

The research team estimated that total deaths from wildfire pollution will reach 1.9 million people between 2026 and 2055 if climate change continues unabated. 

The study predicts that California will experience the largest increase in premature deaths, followed by New York, Washington state, Texas and Pennsylvania. 

The authors estimated that the annual excess deaths under a high greenhouse gas emissions scenario, where the Earth continues to warm rapidly, would result in yearly economic losses of $608 billion by 2050.

Globally, as many as 1.4 million people may die prematurely each year by the end of the century due to increased wildfires induced by climate change, according to a separate study examining the worldwide health impacts of wildfire smoke, which was also published Thursday in the journal Nature. Burke was not involved in this study. 

Matt Rahn, research director of the Wildfire Conservancy, a California-based nonprofit organization focused on improving firefighter health and safety, said he wasn’t surprised by the studies’ findings.

“Every year we seem to be setting new records,” Rahn, who was not involved in either study, said of the rising number of wildfires and their severity. “It’s been demonstrated time and again that after every major incident, the surrounding communities have an uptick in cardiac and pulmonary cases at local emergency rooms and clinics, not to mention the long-term effects of cancer risk, especially among our first responders.”

The findings come as the U.S. Environmental Protection Agency under President Donald Trump is preparing to roll back its endangerment finding on greenhouse gases. The 2009 finding is a formal declaration by the agency, later affirmed by the U.S. Supreme Court, stating that greenhouse gases pose a threat to public health. The finding allows for greenhouse gases to be regulated under the Clean Air Act, the United States’ primary federal law to control air pollution.

“Our results provide some of the strongest evidence that a warming climate endangers the health of U.S. citizens,” Burke said, noting that the agency is currently accepting public comment on its proposed rollback through Sept. 22. “We hope that our results can help inform that policy decision.”

Burke noted that decades of fire suppression policies have also played a role in the ongoing escalation in wildfires, a factor that was accounted for in the current studies. He said an increase in prescribed burns, fires started intentionally and managed by trained professionals, is needed to reduce the risk of extreme wildfires.

Controlled burns also release harmful smoke, Burke noted, but he added that by choosing when to conduct the burns and by limiting their growth, firefighters can reduce the negative health impacts.

“It is, unfortunately, a trade-off,” Burke said. “But it is much lower risk than our current status quo, which is doing very little of this, and thus having very little control over the amount of wildfire we get and who is exposed and at what magnitude.”

Rahn, of the Wildfire Conservancy, added that simple measures, such as providing N95 masks or other air-filtering equipment to firefighters and other first responders would go a long way toward reducing health impacts to those breathing in the most wildfire smoke.

“It’s not just the firefighters that are on the front lines,” Rahn added, noting that law enforcement personnel and utility company employees working to restore power, water and gas lines also face significant exposure.

A recent investigation by The New York Times highlighted the health challenges that wildland fighters face and noted that the U.S. Forest Service did not provide masks to its firefighters. The Forest Service subsequently ended its decades-long ban on providing those masks. 

Cover photo:  A thick haze blankets New York City as smoke from Canadian wildfires impacts air quality on August 5. Credit: Selcuk Acar/Anadolu via Getty Images