How the climate contributes to forest fires like those in Chile

At least 123 people have died from fires forestry in Chile, which led its president to declare two days of national mourning. The devastation occurred shortly after the declaration of a disaster in Colombia due to other fires. Scientists say that the climate change It makes heat waves and droughts like those currently facing South America more likely, and both contribute to fires by drying out the plants that fuel the flames.

What is happening in Chile?

The fires in Chile occurred during a heat wave that raised temperatures in the capital, Santiago, to about 37 degrees Celsius (almost 100 degrees Fahrenheit). The extreme heat evaporates moisture from the wood, making it the ideal fuel. Fires spread faster and burn more intensely. Just a few additional degrees can mean the difference between a moderate fire season and a severe one.

Climate change “warms the world, meaning more water evaporates from plants and the earth dries out more”explained Edward Mitchard, a forest expert at the Faculty of Geosciences at the University of Edinburgh in Scotland.

It only takes a few days of very dry, hot weather for the leaves to be dry and brittle, he said. “That’s fuel that burns very well.“, said. “Drier soil makes fires hotter and last longer”.

A Nature study showed that fire seasons last on average 18.7% longer due to climate change. That extends the period in which disastrous fires can start.

How do global weather cycles influence?

The increase in droughts due to alterations in global rain cycles means that entire regions may become unusually arid and more vulnerable to flames.

“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, there is also less rain in southern South America”.

In the case of Chile, unusually heavy rains last year are believed to have increased the growth of bushes that became the ideal fuse for fires.

Added to this is the meteorological phenomenon of El Niño, a natural and periodic warming of the waters on the surface of the Pacific that affects the weather throughout the planet. In South America it has meant an increase in temperatures and droughts this year.

Climate change makes El Niño cycles more likely to be stronger, Mitchard said, and the droughts it causes are more likely to be more intense. Last month, Colombia declared a national disaster due to dozens of fires associated with the meteorological phenomenon.

And the enormous amount of carbon dioxide released by the fires themselves increases global warming.

Are wildfires getting worse?

The World Resources Institute used satellite data to estimate that wildfires now destroy about 30,000 square kilometers (11,600 square miles) of forests a year, about the size of Belgium and twice as much as 20 years ago.

And the Intergovernmental Panel on Climate Change has determined that around the world, extreme heat waves occur five times more often due to human-caused global warming. Therefore, fire seasons are drier and have higher temperatures, ideal conditions for flames to spread.