The frequency and intensity of severe wildfires have doubled in the past 20 years

This article Republished from Conversation under a Creative Commons License,

It seems we are getting used to fires on Earth. Recently, over 70 wildfires Fires also broke out simultaneously in Greece. In early 2024, Chile suffered its worst forest fire in history, More than 130 people were killed. Last year, Record-breaking wildfires in Canada Burns from March to November, and flames out in August devastated The island of Maui in Hawaii. And the list goes on.

Watching the news it certainly seems like catastrophic extreme wildfires are happening more frequently, and unfortunately that sentiment has now been proven correct. New Study A study published in Nature Ecology & Evolution shows that the number and intensity of the most severe wildfires on Earth have doubled over the past two decades.

The authors of the new study, researchers from the University of Tasmania, first calculated the energy released by different fires over 21 years from 2003 to 2023. They did this calculation using a Satellite-based sensors Which can detect the heat produced by a fire, and measure the energy emitted as “fire radiant power”.

The researchers identified a total of 30 million fires (technically 30 million “fire events”, which may include some clusters of fires grouped together). They then selected the top 2,913 that released the most energy, i.e. the 0.01 percent “most extreme” wildfires. Their work shows that these extreme wildfires are occurring more frequently, with their number doubling in the past two decades. Since 2017, the Earth has experienced the most extreme wildfires in six years (all years except 2022).

Importantly, these severe wildfires are becoming more intense. Fires classified as severe in recent years emitted twice as much energy as fires classified as severe at the beginning of the study period.

These findings are consistent with other recent evidence that wildfires are getting worse. For example, the area of ​​forest burned each year is increasing slightly, leading to an increase in the number of wildfires. Increase in forest carbon emissions. (The total land area burned each year is actually Decreasing(Due to a reduction in grassland and crop fires, but these fires are less intense and emit less carbon than wildfires.)

severity of burnsFire intensity—an indicator of how badly fires damage ecosystems—is getting worse in many regions, and the percentage of burned land affected by high-intensity fires is also increasing globally.