Extreme forest fires have doubled in the last 20 years around the world: global warming due to human activity could be the cause

Temperate coniferous forests and boreal forests are the most affected, with the frequency of such fires increasing 11-fold and 7-fold respectively. Toa55/Getty Images

The number and intensity of extreme forest fires, the most destructive and polluting, have more than doubled worldwide over the past 20 years, due to global warming caused by human activity, according to a new study published Monday, June 24, 2024.

The number and intensity of extreme forest fires, the most destructive and polluting, have more than doubled worldwide over the past 20 years, due to global warming due to climate change. #39;human activity, according to a new study published Monday June 24, 2024.

Using satellite data, researchers studied nearly 3,000 wildfires with enormous "radiative power" – the amount of energy emitted by radiation – between 2003 and 2023 and found that their frequency had increased by a factor of 2.2 during this period.

It is the temperate coniferous forests, particularly in the western United States, and the boreal forests, which cover Alaska, northern Canada and Russia, which are the most affected, with a frequency of such fires multiplied respectively by 11 and 7.

Considering only the 20 most violent fires of each year, their cumulative radiative power has also more than doubled, at a rate that "seems&# 39;accelerate", according to the study published in the journal Nature Ecology & Evolution.

"I expected an increase, but this rate of increase alarmed me" said lead study author Calum Cunningham of Australia's University of Tasmania.

"The effects of climate change are no longer in the future and today we see signs of an atmospheric which dries out and warms up", he told AFP, pleading for better preventive management of forests.

The 6 most extreme years since 2017

The six most extreme years for wildfire intensity and frequency have occurred since 2017, the study found. Confirming the trend, it was the year 2023, the most recent, which experienced "the most extreme forest fire intensities' quot; over the period studied.

These extreme fires are fueled by increasingly severe drought, a consequence of global warming.

During its growth, the forest cover absorbs CO2, but it returns en masse to the atmosphere when the vegetation burns, aggravating global warming caused by carbon emissions. greenhouse gas. This creates a "feedback effect", Mr. Cunningham said.

In addition, with these fires, "vast regions are crossed by the plume of smoke, which has significant effects on health and leads to many more deaths. premature deaths than the flames themselves", underlined the researcher. His study cites in particular work according to which air pollution due to megafires in 2015 in Indonesia led to an excess mortality of 100,000 people.