Ten ways of climate change can weaken forest fires


PARIS: Deadly forest fires, such as the Northern and Southern California horrific, have become more common in recent years in the state and in the rest of the world. AFP discussed with researchers how climate change can weaken them.

Other factors have also increased the frequency and intensity of significant fires, including injuries to people in forest areas and questionable forestry. "The patient was already sick," says David Bowman, professor of environmental biology at the University of Tasmania and hunting expert.

"But climate change is an acceleration."

Every firefighter can tell you "favorable fire-fighting": hot, dry and windy.

It is no surprise, therefore, that many tropical and temperate areas that are destroyed by forest fires are those predicted by climate models to increase temperatures and droughts.

"In addition to climate change – adding evaporative rates and drought precipitation – creating additional hot and hot air will increase the inflammable ecosystems," said Christopher Williams, Clerk University of Environmental Sciences, Massachusetts.

During the last 20 years, several droughts have been observed in California and Southern Europe, which occurred only once in the century.

Dry weather means more dead trees, shrubs and grass – and more fuel for fire.

"All these extremely dry years create a huge amount of dried biomass," says Michel Vennetier, an engineer at the French Institute for Environmental Research and Technology (IRSTEA).

"It's ideal for burning."

To make things worse, new species that are better suited to semi-arid conditions will grow in place.

"Plants that hold moisture have disappeared, replaced by flammable plants that endure dry conditions such as rosemary, wild lavender and thyme," said Vennetier.

"The change happens quite quickly."

Thanks to mercury and less rain, water-resistant trees and shrubs eat deeper into the soil, absorb each drop of water that they can feed leaves and needles.

This means that the humidity of the Earth, which would have helped slow down the spread of fire through a forest or garrigue, is no longer there.

In the temperate zone of the Northern Hemisphere, the burning season was historically short in most places – July and August.

"Today, the vulnerable period of fire has continued from June to October," said IRSTEA scientist Thomas Curt referring to the Mediterranean basin.

In California, which has only recently come from five years of drought, some experts say that there is no longer a season – fires can occur all year round.

"The more warmer it gets, the more flash you have," says Mike Flannigan, Professor of University of Canada at the University of Canada, and Wildlife Fire Science's Western Partnership.

"Especially in the northern areas, which means more fires."

At the same time, he said that people have started 95 percent of global forest fires.

Normal weather conditions in North America and Eurasia are heavily dependent on strong high-speed air flows – which are generated between polar and equatorial temperatures – referred to as the "spray".

But global warming has raised the temperature in Arctic twice as fast as the global average, which weakens these currents.

"We see the extreme weather because we call clogged ridges, a high-pressure system where air crashes, warms up and dries on the road," Flannigan said.

"Firefighters have known for decades that they promote fire."

Climate change increases not only the probability of forest fires, but also their intensity.

"If the fire becomes too strong" as it is in California right now, and in Greece last summer, "there is no immediate action that you can stop," said Flannigan.

"It's like spitting on a fire."

With rising temperatures, beetles have moved north to the Canadian boreal forests, destroying destruction – and killing trees – along the way.

"The bursting of the shell burglar provisionally increases the firepower of the forest fire by increasing the amount of dead material, such as needles," Williams said.

Worldwide, forests account for about 45 percent of global carbon capture and enjoy a quarter of human greenhouse gas emissions.

But when the forests die and burn, some of the carbon is released back into the atmosphere, which promotes climate change in a desperate loop that researchers call "positive feedback".


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