PARIS, November 12 – Fierce forest fires in northern and southern California have become more widespread in the world and elsewhere in the world. The AFP spoke to scientists about ways in which climate change could worsen them.
Other factors have also led to an increase in the frequency and intensity of large fires, including rape and questionable forest management in forested areas. David Bowman, professor of environmental change biology at the University of Tasmania, and a wildfire expert, said, n the patient was already ill Taz.
. But it is a climate change accelerator. “
Nice weather for a fire
Any fireman can tell you the description of: favorable fire air bilir: hot, dry and windy.
At that time, many of the tropical and temperate regions caused by an increase in forest fires were not surprising in climate models to see higher temperatures and more drought.
Christopher Williams, director of environmental sciences at Clark University, Clark, said: yan Drier and warm weather has created more flammable ecosystems as well as bringing about the increasing rate of evaporation and drought of climate change Massachusetts.
In the last 20 years, California and southern Europe have seen a drought that is only a few times in the century.
Dry air means more dead trees, bushes and lawns and more fuel to fire.
Michel Vennetier, one of the engineers of the National Environmental and Agricultural Scientific Researches (IRSTEA) in France, said, biri It is an extremely dry whole, which makes up a large amount of dried biomass in these years. Fransa
“This is ideal flammable.“
To make matters worse, new species that are better adapted to semi-arid conditions grow in their own places.
Vennetier, "Flavored plants lost moisture, rosemary, wild lavender and dry conditions such as thyme can replace the more flammable plants took place," he said.
”The change is happening pretty fast.“
With rising mercury and less rain, water-damaging trees and shrubs send deeper roots to the soil, absorbing every drop of water to feed the leaves and needles.
This means there is no more moisture on the earth that can help slow down a sweep through a forest or garrigue.
In the temperate zone of the northern hemisphere, the fire season is historically short – July and August, in most places.
. Today, the forest-sensitive period has been extended from June to October, atıl said IRSTEA scientist Thomas Curt, referring to the Mediterranean basin.
In California, a recent five-year drought, some experts say it is not a season – fires can occur throughout the year.
Wild When it's hotter, there's more lightning, lann said Mike Flannigan, professor at the Canadian University of Alberta and director of Western Partnership for Wildland Fire Science.
”Especially in the northern regions, this is becoming more and more fire“.
He also said that 95 per cent of world-wide forest fires were initiated by humans.
Weak jet flow
The normal weather patterns on North America and Eurasia depend on strong and high altitude air currents – produced by the contrast between the polar and equator temperatures – known as jet flow.
However, global warming increased the temperatures in the Arctic twice as fast as the global current and weakened these currents.
. We see more extreme weather because what we call clogged ridges, a high-pressure system where the air goes down, becomes hotter and drier, F Flannigan said.
”Firefighters have known for decades that they are suitable for fire operations.“
Climate change not only increases the likelihood of forest fires, but also increases its severity.
Flannigan said,; If the fire is very concentrated as it is in California right now geçen and last summer in Greece, a there is no direct measure you can make to stop F.
Ateş It's like spitting a campfire. “
With increasing temperatures, insects moved northward through the boreal forests of Canada, causing damage along the way – and killing the trees – along the way.
”Outbreaks of shell beetles increase the amount of dead matter, such as needles, temporarily increases flare in the forest, Williams Williams said.
Globally, forests hold approximately 45 percent of Earth's locked carbon and consume a quarter of human greenhouse gas emissions.
But with the death and burning of forests, part of the carbon is released back into the atmosphere and contributes to climate change, a vicious circle that scientists call ve positive feedback Fakat. – AFP