By: Owain Delf
California experienced a fairly quiet wildfire season in 2023, particularly compared to recent record years in 2020 and 2021. However other places, such as Canada, saw unprecedented wildfire seasons and impacts to humans, which the authors say were undoubtedly exacerbated by climate change.
The overview, conducted by researchers from the US, Canada, and the UK - including the University of East Anglia (UEA) - is published today as part of a special issue commissioned by the journal Nature Reviews Earth and Environment. This aims to highlight how climate change impacted critical earth components in 2023, including CO2 emissions; heat extremes; wildfires; precipitation extremes; sea ice; terrestrial water storage; vegetation greenness; climate policy and ocean heat content.
Led by Dr Crystal Kolden, Director of the University of California Merced’s new Future-Ready Fire and Climate Center, the ‘Wildfires in 2023’ paper highlights devastating wildfires around the world.
The team found the global area burned reached 384 millihectares (Mha) in 2023. This total is substantially higher than the past few years, including 2020 (351 Mha), 2021 (354 Mha) and 2022 (329 Mha). However, the 2023 total remains 12% lower than the 2001–2010 annual average of 437 Mha, a considerably more active fire period. Fire carbon emissions also peaked in 2023, reaching an estimated 2,524 teragrams of carbon (Tg C), 30% of which came from Canada’s record fire season.
Key points from the review:
• The hottest year on record facilitated destructive wildfires on six continents, with 70% of total burned area occurring in the Northern Hemisphere.
• Canada experienced its most severe fire season in the modern era (more than doubling burned area of the previous record), while extreme fire weather resulted in catastrophic fires in Hawaii, the Mediterranean, central Amazonia and central Chile.
• Extreme events produced mass fatalities, lengthy evacuations and extensive economic losses.
Co-author Dr Matthew Jones, of the Tyndall Centre for Climate Change Research at UEA, said: “We saw low burning in some of Earth’s most flammable regions in 2023, particularly in African and South American savannahs. On the other hand, we saw truly staggering fire extent in unexpected regions, most notably in Canada, Chile, the interior of the Amazon and northern parts of South America.
“The global fire season was also punctuated by devastating events that cost so many lives and livelihoods in Hawaii, Greece, Chile and elsewhere. Many of these events can be tied to extreme weather conditions, such as droughts, which are becoming less and less unusual as the climate warms.”
The authors show that due to more than 37 million acres burned in Canada, northern hemisphere wildfires unusually emitted more carbon to the atmosphere than the southern hemisphere.
The carbon emissions alone were considered a disaster because they erased decades of work to reduce carbon emissions in Canada. But wildfires in Greece, Chile, Algeria, and Hawaii also killed hundreds of civilians collectively due to record heat and aridity.
“Global wildfire is declining overall because humans are doing less agricultural burning in Africa, and when you combine that with a pretty quiet fire year in the US, people tend to overlook that wildfire disasters are increasing,” said Dr Kolden. “We wanted to highlight how climate change is creating hot spots of unprecedented fire behaviour.
“The problem with climate change is that it’s not just gradually warming the Earth. It’s also producing these extreme fire weather days more frequently, providing more opportunities for accidental ignitions to blow up into fatal fires.
“The same type of extreme fire conditions that killed 100 people in Hawaii last August killed 34 in Algeria, 28 people in Greece, and 26 people in Chile in 2023. People rarely used to die in wildfires, and now there are dozens of fatalities every year.”
The authors hope the review will help highlight the need for more action to mitigate wildfire disasters.
“Most countries, including the US, are still putting all their eggs in the fire suppression basket. We need to do more specifically to avoid fatalities, or such disasters will only increase,” added Dr Kolden.
‘Wildfires in 2023’, Crystal A Kolden, John T Abatzoglou, Matthew W Jones & Piyush Jain, is published in Nature Reviews Earth and Environment on April 4.
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