Scientists found that Climate change increased the frequency of “extreme” wildfires by 25% on average compared to the pre-industrial era.
They examined a series of blazes during the 2003-2020 period and used machine learning (ML) to analyze the link between higher average temperatures, dryer conditions, and the fastest-spreading blazes.
In certain partly dry conditions, global warming pushed the area beyond key thresholds. This makes the extreme fires much more likely but in very dry conditions, the impact was less.
“This means that we should pay the closest attention to the places and times that historically have experienced conditions just on the moist side of these thresholds,” Patrick Brown told AFP.
The risk could increase on average by 59% by the end of the century under a “low-emissions” scenario where global warming is limited to 1.8 degrees Celsius above preindustrial levels.
Using data from recorded fires, the researchers measured the probability of a given blaze turning into an “extreme” one.
Then they used computer models to calculate how far the post-industrial rise in temperatures had increased that risk.
The study controlled for variables such as precipitation, wind, and absolute humidity. Researchers warned that changes in these could make the risk of global warming even worse.
A 2022 United Nations (UN) Environment Programme report on wildfires revealed that they are becoming more common due to hotter, dryer conditions caused by climate change, including in regions not traditionally prone to them.
Nature study author Brown underlined that the insights into dryness thresholds could aid prevention measures.
For example, they can indicate the best spots for thinning and prescribed burning of vegetation to reduce the dry natural matter that wildfires feed on, known as “hazardous fuel”.
“We are finding that under most conditions, the impact of hazardous fuel reductions can completely negate the impact of climate change,” he said.
