Extreme wildfires have more than doubled in frequency and intensity in the last 20 years, according to a new research paper published in the Nature Ecology and Evolution journal.
Scientists led by Calum Cunningham, a pyrogeographer at the University of Tasmania in Australia studied NASA satellite data on the top 0.01% of wildfires between January 2003 and November 2023, with a sample size of 2,900. Ranking these extreme fires by the amount of daily energy they released, the authors found that the number of fires had increased by a factor of 2.2, and their intensity had gone up by 2.3. They also found that 2023 saw the most intense wildfires on record, a pattern that was repeated for six of the last seven years.
Vicious circle
Attributing the increases to global warming, the scientists are also warning that the blazes themselves risk creating a vicious circle. The fires exacerbate the problem due to the way they release even more carbon dioxide into Earth’s atmosphere (and destroy the trees that can sequester carbon), adding to the baking greenhouse effects that then go on to create more fires.
What’s more, some of the ecosystems affected by wildfires, such as boreal habitats in northern Europe and North America, not only saw a steeper rise in fires (increasing 7.3 fold) but also suffered permafrost thawing, contributing to the Arctic heating twice as fast as the rest of the planet.
The rise in nighttime temperatures is another factor causing concern, giving firefighters no reprieve as the extreme wildfires they deal with are less and less likely to die down in cooler nighttime conditions.
“Action is urgent”
“The fingerprints of climate change are all over this rise,” Cunningham told The Guardian. “We’ve long seen model projections of how fire weather is increasing with climate change. But now we’re at the point where the wildfires themselves, the manifestation of climate change, are occurring in front of our eyes. This is the effect of what we’re doing to the atmosphere, so action is urgent.”
Every month for the last year, from June 2023 to May 2024, has broken global high-temperature records, a grim milestone that Friederike Otto, a climate scientist at Imperial College London, points out means “record human suffering. Within this year, extreme heatwaves and droughts made much worse by these extreme temperatures have caused thousands of deaths, people losing their livelihoods, being displaced. These are the records that matter.”
