New research has revealed that global warming is leading to more extensive wildfire activity worldwide and is likely causing an additional 12,000 annual deaths due to smoke inhalation. The increased risk from wildfire smoke is particularly noticeable in Australia, South America, Europe, and the boreal forests of Asia, according to one modeling study.
Another study covering 2003 to 2019 found that global heating had expanded the burned area by nearly 16%, although other human activities, such as deforestation and land conversion for agriculture, had reduced the total area affected by 19%. Both studies, published in *Nature Climate Change*, examined how greenhouse gas emissions are influencing wildfire patterns compared to other human actions like land clearing.
Led by Dr. Chae Yeon Park from Japan’s National Institute for Environmental Studies, one study estimated that nearly 100,000 people died each year in the 2010s from inhaling smoke containing fine particles known as PM2.5, which can penetrate the lungs and bloodstream. The link between global heating and these deaths is complex, as hotter temperatures and lower humidity heighten fire risks, but other human activities can limit or suppress fires.
To address this challenge, researchers compared three models of global vegetation and wildfire behavior under current climate conditions with a scenario excluding modern climate change effects. Despite variations in results, researchers from eight countries, including the UK, the US, Germany, and China, consistently found that global heating contributed to an increase in deaths from exposure to PM2.5 from wildfires. In some areas, rising temperatures were the primary factor, while in others, lower humidity played a larger role.
The authors noted that the health impacts of wildfire smoke could be underestimated, as particles from fires are more harmful than those from other sources. Professor Hilary Bambrick from the Australian National University highlighted the severe air pollution during the 2019–2020 Australian black summer fires, which caused hundreds of deaths and likely long-term health effects.
Another study led by UK and Belgian scientists found that global warming was particularly escalating wildfire risks in Australia, Siberia, and African savannas. Seppe Lampe of Vrije Universiteit Brussel pointed out that while land-use changes have reduced the burned area, the impact of climate change is steadily increasing. Professor Wim Thiery, a co-author from VUB, emphasized that the rate at which climate change is expanding the burned area is accelerating each year.
