PARIS: Climate change has sharply boosted the risk of fast-spreading wildfires, according to a Californian study published on Wednesday (Aug 30) that offers lessons for prevention after recent disasters in Canada, Greece and Hawaii.
Scientists at the Breakthrough Institute, a non-profit research centre, found that human-caused warming increased the frequency of “extreme” wildfires by 25 per cent on average compared to the pre-industrial era, in a study in the journal Nature.
Examining a series of blazes from 2003 to 2020, they used machine learning to analyse the link between higher average temperatures, dryer conditions and the fastest-spreading blazes – ones that burn more than 10,000 acres (4,000 hectares) a day.
The impact of climate change varied from fire to fire.
In certain partly dry conditions, global warming pushed the area beyond key thresholds, making extreme fires much more likely. 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, but which are being pushed over these thresholds onto the dry side by background warming,” lead author Patrick Brown told AFP.
FIERCE WILDFIRE SEASON
The researchers calculated that the risk could increase on average by 59 per cent by the end of the century under a “low-emissions” scenario where global warming is limited to 1.8 degrees Celsius above preindustrial levels, and up to 172 per cent in an unbridled high-emissions scenario.
Earth’s surface has already warmed 1.2 degrees Celsius.
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 and the researchers warned that changes in these could make the risk from global warming even worse.
California has suffered a string of extreme wildfires in recent years.
Source: CNA
