Forest fires have doubled worldwide in the last 20 years, particularly in boreal forests, “probably” because of climate change, according to a study published.
The situation is especially dramatic in countries like Russia, which experienced unprecedented fires last year, while the “El Niño” phenomenon has exacerbated the loss of forest mass in Latin America, explained the joint report by Global Forest Watch (GFW), World Resources Institute (WRI), and the University of Maryland.
Compared to 2001, in the last two decades fires have swept around 3 million hectares each year, the equivalent of the area of Belgium.
70% of the area devoured by the flames is concentrated in the forests further north, in regions of Russia, Canada and Alaska, the largest carbon deposits on the planet so far. Russia lost 53 million hectares in the last two decades, the equivalent to the surface of France.
But the situation is also dramatic in Brazil, which lost 9.5 million hectares in that period, the equivalent of 15% of the world total. “Two-thirds of these losses occur in primary forests, which are important reserves of carbon and biodiversity,” the text explained.
Climate models suggest that in some areas of the planet, such as the Amazon or the Mediterranean, the frequency of fires in modern times “is unprecedented compared to recent historical climate, due to human-induced global warming of about 1 .1 °C”, they explain in a statement issued by the University of East Anglia.
These same models also reveal that the likelihood of severe wildfires in the western United States, Australia, and Canada is “significantly higher” in recent times. The most serious thing is that “this will be the case in practically all regions of the world if global temperatures reach 2-3 °C of warming according to the current trajectory,” they warn.
Lead author Dr Matthew Jones, from UEA’s Tyndall Center for Climate Change Research, said: “Wildfires can have massive detrimental impacts on society, the economy, human health and livelihoods, biodiversity and carbon storage. These impacts are generally magnified in the case of forest fires.
“Clarifying the link between wildfire trends and climate change is critical to understanding wildfire threats in future climates. Societies can drive or offset rising fire risks due to climate change, and regional actions and policies certainly can be important in preventing forest fires or reducing their severity.
Key findings of the analyzes include:
- The length of the annual fire season has increased by 14 days per year (27%) during 1979-2019 on average globally and the frequency of extreme fire days has increased by 10 days per year (54%) during 1979-2019 on average worldwide.
- Fire weather has increased significantly in most regions of the world since the 1980s. The increases have been particularly pronounced in western North America, the Amazon, and the Mediterranean. Fire climate has already emerged beyond its natural variability in the Mediterranean and Amazon due to historical warming.
- At 2°C, this will also occur in the boreal forests of Siberia, Canada, and Alaska and in the temperate forests of the western US. At 3°C, virtually every region of the world will experience unprecedented fire weather.
- Globally, the area burned by fires has decreased by around a quarter, or 1.1 million km2, during 2001-2019. Much of the decrease, 590,000 km2, has occurred in the African savannas, where between 60 and 70% of the area burned by fire occurs annually. Local/regional human impacts have reduced the area burned by fire in tropical savannahs, in combination with lower grassland productivity during (increasingly drier) wet seasons.
- Large increases in the area burned have been seen elsewhere, especially in temperate and boreal forests. For example, the area burned by fire has increased by 21,400 km2 (93%) in the forests of eastern Siberia and by 3,400 km2 (54%) in the forests of western North America (Pacific Canada and US combined).
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