The number of days with hot, dry, and windy conditions, all perfect for fuelling extreme wildfires, has nearly tripled globally over the past 45 years, with human-caused climate change driving more than half of the rise, a new study has revealed.
Published in Science Advances, the research highlighted what it deemed a “synchronous fire weather,” where dangerous conditions align across large regions or even continents, making widespread fires harder to control and straining firefighting resources.
“These sorts of changes that we have seen increase the likelihood in a lot of areas that there will be fires that are going to be very challenging to suppress,” study co-author John Abatzoglou, a fire scientist at the University of California, told news agency Associated Press (AP).
HOW MUCH HAVE WILDFIRE DAYS INCREASED?
From 1979 to the mid-1990s, the world averaged about 22 synchronous fire weather days per year within major regions. By 2023–2024, that figure had climbed to more than 60 days annually.
“It increases the likelihood of widespread fire outbreaks, but the weather is one dimension,” lead author Cong Yin, a fire researcher at the University of California explained.
Other factors like dry trees and bushes, oxygen, and ignition sources like lightning and human activity also play key roles.
Instead of actual fires, the study focused on weather conditions: high temperatures, low humidity, dry soils, and strong winds.
HOW MUCH OF HOT DAYS ARE CAUSED BY CLIMATE CHANGE?
More than 60 per cent of the global increase in the number of such hot days was due to warming caused by burning fossil fuels like coal, oil, and natural gas.
Researchers used computer models to compare real-world data with a hypothetical scenario without added greenhouse gases to arrive at the estimate.
And as emissions continue uninterrupted and global leaders fail to secure an agreement to phase out fossil fuels, the planet is expected to warm further. The warming is such that the landmark Paris Agreement’s set target of containing the warming to 1.5C could fail.
The trend is being noticed across the world.
Regions that once had staggered fire seasons could share firefighting crews and equipment. Now, overlapping dangerous periods mean regions are more unprepared and struggling to contain the fires.
The weather extremes have increased in intensity as well as frequency. Countries are facing extreme heat every summer, the kind of heat that is made worse by urbanisation and the kind for which humans are not prepared for.
WHAT REGION IS WORST AFFECTED BY CLIMATE FUELLED WILDFIRES?
India’s Uttarakhand state recently experienced a similar fire.
The region housing a vast portion of the Himalayas and often offering respite to those escaping the urban heat, itself burned. Dry conditions and a surprising lack of snow and winter rain created dry conditions in the mountains. The conditions soon translated into a forest fire in the Nanda Devi National Park that lasted for days.
Although India has experienced soaring temperatures for months, the trend is sharpest in North and South America.
In the continental US, synchronous fire weather days rose from an average of 7.7 per year, between 1979 and 1988, to 38 in recent years.
South America’s southern half saw an even steeper jump. The number of days rose from 5.5 days annually between 1979 and 1988 to 70.6 in the last decade, hitting 118 days in 2023.
Of 14 global regions studied, only Southeast Asia showed a decline, likely due to increasing humidity.
Despite that, instances exist where dry and hot weather compounded by human activities causes forests to burn.
As the planet continues to warm, experts warn that simultaneous fire risks could overwhelm suppression efforts worldwide, underscoring the urgent need to curb emissions and adapt to changing fire patterns.
