Extreme wildfire events made the 2023-24 fire season record-breaking for numerous reasons: Canada’s largest wildfire ever spewing unprecedented emissions, deadly fast-moving fires in Hawaii and Chile, and widespread fires throughout South America.
The season’s historic nature made it the perfect case study for the first-ever State of Wildfires report, a collaboration of over 40 researchers from across the world working to understand how human-driven climate change, through the burning of fossil fuels, is influencing wildfire trends. Stakeholders hope the potentially yearly report will help bridge the gap between researchers and fire agencies.
“If it was just academics using data, it could lead to a lot of amazing research, but at the moment it’s this really good record for fire agencies and communities to tap into and really understand what happened over the last year,” said Dr. Sarah Harris, co-author of the paper and manager of research and development at Australia’s Country Fire Authority. “Local fires are put in the context of climate change in the report, so you get to learn more about how climate change is playing a role.”
The researchers found that climate change increased anomalies in burned areas by up to 18%, 40%, and 50% in Greece, Canada, and western Amazonia, respectively. They also found that while overall burned area was slightly below average from previous seasons, fire carbon emissions were 16% above average, driven by record emissions from Canada’s boreal forests that were over nine times the average.
Climate change reportedly made extreme fire seasons at least 3.6 times more likely in Canada and at least 20 times more likely in Amazonia.
“By the end of the century, events of similar magnitude to 2023 in Canada are projected to occur 6.3–10.8 times more frequently under a medium–high emission scenario,” the report said.
The probability of fires in Canada and Greece increased primarily due to a combination of high levels of fire weather and an abundance of dry fuels. In contrast, areas with lower fuel loads and higher direct fire suppression experienced weaker burned-area anomalies.
Meanwhile, increases in wildfire frequency and severity in Amazonia constitute a “major event of global relevance” for numerous reasons, according to the researchers. Those reasons include severe air quality degradation, widespread environmental degradation, and broad socioeconomic and health impacts.
“The trend in Amazonas, among the most pristine parts of Amazonia, contrasts with other states of Brazil such as Mato Grosso and Pará, where deforestation rates and deforestation-related fires have fallen since their peak during the early 2000s,” the report said. “The anomalous fire activity and carbon emissions in the State of Amazonas during the 2023–2024 fire season (but not other states of Brazil) thus appear to be consistent with the emerging pattern of increased fire in the region.”
The researchers said in all major focal events the report studied, extremely burned areas were driven by the synchronized critical factors of weather, fuel moisture, and fuel abundance. That fact underscores the reality that no single bioclimatic factor can be blamed for severe fires.
The high-emission scenarios the researchers studied lead to significantly increased likelihoods of major fire events like those seen during the 2023-24 fire season. However, strong climate change mitigation efforts can avoid significant portions of increased risk, as emphasized by the researchers’ findings.
Harris, who is also a board member of the International Association of Wildland Fire, said stakeholders hope the scope of the report is expanded even further to include more communities and local agencies.
“The plan going forward is broadening the scope of the regional liaisons to have a rotating panel and ensure we have diversity in there, and making sure not just diverse people, but also academic and fire agencies’ relationships are maintained,” Harris said. “Making sure we reach out to smaller areas to make sure the report is capturing their experiences.”
