Wildfire Smoke Set To Cause Mounting Deaths And Economic Losses

Increased wildfire smoke could lead to 1.4 million premature deaths globally each year by the end of this century, according to a new study.

Scientists at China’s Tsinghua University found that early deaths linked to particulate matter in wildfire smoke could rise to six times 2010-2014 levels by next century depending on how much global carbon emissions increase. Africa could see an elevenfold jump in deaths.

In another study, researchers at Stanford and Stony Brook University separately found that wildfire pollution could lead to over 71,000 premature deaths by 2050 in the US under a high emissions scenario. For the past decade, an average of 40,000 people died prematurely every year due to exposure to wildfire smoke. Both reports were published in Nature on Thursday.

“The results were pretty striking,” said Marshall Burke, a professor at Stanford University and a co-author of the US-focused study. “Our result provides some of the strongest evidence that a warming climate endangers the health of US citizens.”

Billions of people globally were exposed to hazardous levels of small airborne particulates known as PM2.5 on at least one day a year due to large fires that burned between 2000 and 2019, according to the authors of the global study. Wildfires have a more negative impact in human health because blazes in forests can unearth heavy metals on the soil, including lead and other cancer-causing substances.

People suffering asthma and other respiratory conditions can be immediately impacted by the smoke. Over the longer term, other conditions can be exacerbated because PM2.5 particles get deep into the lungs and filter into the blood, wreaking havoc across the body, Burke said.

“Science is catching up in terms of toxicity of wildfire smoke,” he said. “It's likely the mortality we see reflects this toxicity.”

There’s also an economic toll. The US-focused study estimated damage to the country based on different scenarios for future global carbon emissions. The cost could reach $608 billion a year by 2050 if emissions are high. Health impacts from wildfire smoke in the US are larger than all other quantified damages of climate change combined, he said.

Smoke from blazes are already affecting municipal credit markets, according to Bloomberg Intelligence, driving up borrowing costs for hospitals and nursing homes.

While cutting planet-warming greenhouse gas emissions will reduce risk over the longer term, countries should focus on adapting by managing existing fuel sitting in forests through controlled burns, the researchers said. Educating people on how to protect themselves — including by closing doors and windows and installing air filtration devices — could also be beneficial, Burke said.

A global response is crucial because wildfire pollution from one country can impact regional neighbors. "Because wildfire smoke crosses boundaries, traditional local air-quality regulations are often inadequate," said Bo Zheng, one of the authors of the global study. "Coordinated regional and international strategies are needed."