More than 1 billion people a year now face heat waves and wildfire smoke at once, study finds
Exposure to the combined hazard rose sharply from the 2000s to the 2010s, with countries in southern and central Africa among the hardest hit per person.
More than 1 billion people a year were exposed to heat waves and wildfire pollution at the same time between 2010 and 2019, up from 761 million a year in the previous decade, according to a study published in the journal Science Advances.
The overlap matters because each hazard worsens the health effects of the other. The researchers found that rising temperatures now shape fire patterns more than rainfall does, and that heat and fire can feed each other in a loop.
The average number of days each person faced both hazards rose from one day in 2000-2009 to 1.7 days in 2010-2019. Zambia, the Democratic Republic of Congo, Malawi, Guatemala and Burundi had the highest exposure per person, while populous countries including Congo, Indonesia, Mexico, Brazil and Russia accounted for more than half of all exposure days worldwide.
Lead author Yao Wu of Monash University in Australia, who worked with co-authors from universities in China and Australia, said the increase comes mainly from people facing both hazards together more often, not from population growth alone.
Outside experts, including Tarik Benmarhnia of the University of California San Diego, said public health plans need to address overlapping hazards together rather than one at a time. Suggested steps include cooling centers, buildings that filter out smoke and heat alerts that also carry air-quality warnings.
This brief is based on an article published Oct. 14, 2026, by Katie Surma in Inside Climate News. Read the original: https://insideclimatenews.org/news/14102026/climate-change-fueling-heat-waves-and-wildfire-smoke/
This article was produced with the assistance of AI tools and reviewed by an editor before publication.
