Dozens of people have been killed by forest fires in central Chile, which led its president to declare two days of national mourning. The devastation comes shortly after Colombia declared a disaster over wildfires. Scientists say climate change makes the heat waves and drought now gripping South America more likely, and both contribute to wildfires by drying out the plants that fuel the fires.
WHAT IS HAPPENING IN CHILE?
The fires in Chile occurred amid a heat wave that raised temperatures in the capital city of Santiago to about 37 C (almost 100 F). The extreme heat burns the moisture in the wood, making it the ideal fuel. Fires take root more quickly and also burn more intensely. A few extra degrees could be a tipping point that makes the difference between a mild fire season and a severe one.
Edward Mitchard, a forest expert at the School of Geosciences at the University of Edinburgh in Scotland, said climate change “is making the world warmer, which means plants evaporate more water through them and soils become warmer.” they come back drier.”
It only takes a few days of very dry, hot weather for the leaves to feel crispy and dry, he said. “That’s a fuel that burns very well,” she said, adding, “Drier soil means fires are hotter and last longer.”
A study of nature presented that fire seasons are on average 18.7 percent longer due to climate change. That means a longer window for disastrous fires to start.
WHAT ROLE DO GLOBAL WEATHER CYCLES PLAY?
Increased droughts as global rainfall cycles are disrupted means that entire regions may become unusually parched and more vulnerable to ignition.
“Climate change has made droughts more common,” Mitchard said. “And that has happened especially in South America this year.
“We have had the most extreme drought ever recorded in the Amazon basin, and if there are droughts in the Amazon basin, it also rains less in southern South America.”
In the case of Chile, some unusually heavy rains last year are believed to have increased the growth of weeds that are perfect for lighting fires.
Added to this is the El Niño weather pattern, the natural and periodic warming of surface waters in the Pacific that affects climate around the world. In South America, this meant rising temperatures and drought this year.
Climate change makes El Niño more likely to be stronger, Mitchard said, and droughts caused by it are more likely to be more intense. Last month, the Colombian government declared a disaster for dozens of forest fires associated with the climate phenomenon.
And the enormous amount of carbon released by wildfires increases global warming.
ARE FOREST FIRES GETTING WORSE?
The World Resources Institute used satellite data to calculate that wildfires now destroy about 11,500 square miles of forest annually (30,000 square kilometers), an area roughly the size of Belgium and about twice as large as 20 years ago.
And the Intergovernmental Panel on Climate Change has found that, globally, extreme heat waves occur five times more often due to human-caused global warming. Therefore, fire seasons are drier and have higher temperatures. These are the ideal conditions for forest fires to occur.
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