Smoke billowing from wildfires will cause a growing number of deaths around the world in the decades ahead as the planet continues to heat up, new research has found.
Wildfire smoke is expected to kill as many as 1.4 million people globally each year by the end of the century if planet-heating emissions are not curbed, according to a study published on Thursday.
Separate research, released on the same day, finds a similar spike in wildfire smoke deaths just in the US, with more than 70,000 people set to die in America this way by 2050 at the current rate of warming, up from the 40,000 who die this way each year at this time.
Breathing in smoke from burning forests is thought to be about 10 times more toxic than inhaling other air pollution given off by the burning of fossil fuels, with scientists recently warning the impact of this pollution has been severely underestimated in terms of its impact upon our health.
Wildfire smoke contains ash and soot that contain tiny particles, called PM2.5, which can, when inhaled, burrow deep in people’s lungs and cause an array of respiratory and heart problems.
The reach of this threat is extensive, too – recent research estimated that 22,000 people in Europe were killed due to plumes of wildfire smoke coming from vast forest fires in Canada in 2023, along with many more fatalities in North America.
Fire has long been a feature of landscapes and a variety of factors, such as the management of forests, can influence conflagrations. The area around the world affected by wildfires has actually decreased in the past two decades, mainly due to changing agricultural practices, but, crucially, the number of people exposed to fires has significantly grown in this time.
The climate crisis is the driving force behind the trend of larger, fiercer fires, according to Minghao Qiu, an atmospheric researcher at Stony Brook University. “More warming and higher fuel aridity means that the vegetation gets drier, therefore higher wildfire risks,” he said.
Qiu led the US-focused research, published in Nature, that found that just over 71,000 people are expected to die annually in the country by 2050 due to wildfire smoke on current warming trends.
California, scene of many huge fires including current blazes that threaten the state’s storied sequoia trees, will bear the brunt of these deaths but the smoke will also take a major toll in states such as New York and Texas, the research found.
If emissions aren’t cut, the US could suffer annual economic damages of $608bn by 2050 due to wildfire smoke, more than all other climate hazards combined, the authors estimated.
“Wildfire smoke is by far the largest in terms of overall health damages and that’s a new finding,” said Marshall Burke, an environmental scientist at Stanford and study co-author. “The numbers are really striking.”
Wildfires are an increasing global problem, too, with huge blazes seen in countries such as Canada, Spain and Portugal this year. Much of the harm from smoke is set to be inflicted upon Africa, however, according to another new study, also published in Nature, by an international team of scientists.
The research estimates that worldwide 1.4 million people will die by the end of the century due to wildfire smoke, about six times more than the present death toll, but that this burden will fall unequally. While the US and Europe could suffer a doubling in wildfire smoke deaths, Africa is expected to be worst affected, with 11 times more fire-related deaths compared with current norms.
Longterm wildfire smoke risk will be lessened if the world finally manages to reduce greenhouse gas emissions. However, the death toll for the coming decades will be influenced more by shorter-term adaptation, Burke said.
“If we want to reduce impacts in the next 30 years, mitigation is important, but it’s actually not the key lever,” he said.
“The two key levers are reducing extreme wildfire activity through other approaches, so fuels management, and second, making sure we are well protected when smoke events happen. Right now we are not very well protected.”