Canada’s wildfires last year were unprecedented, generating nearly as much greenhouse gas emissions in one season as would typically occur over a decade of fires under normal conditions. These fires, described as Canada’s “wildest season ever,” were at least three times more likely due to the climate crisis and released around 2 billion tonnes of CO2—about a quarter of the global wildfire emissions for the year, according to the State of Wildfires report released on Wednesday.
The health impacts from these fires are expected to linger for decade. Wildfire emissions globally amounted to approximately 8.6 billion tonnes of CO2 last year, surpassing the U.S. annual emissions from all sources by a significant margin. Although regrowth of vegetation may help absorb some of this carbon, the net effect of wildfires is still a major concern.
Matthew Jones, a research fellow at the Tyndall Centre for Climate Change Research and lead author of the report, emphasized that without a reduction in greenhouse gas emissions, the damage from increasingly intense wildfires will continue to worsen. These fires not only harm people, wildlife, and landscapes but also contribute to dangerous air pollution and amplify the climate crisis through their greenhouse gas emissions and destruction of carbon-storing vegetation and soil.
Canada’s fires were particularly severe, with a burned area six times the average for a typical year. Other regions, such as Brazil’s Amazonas state, Hawaii, Texas, and Greece, also faced significant fires. However, lower-than-usual burning in African savannahs kept last year’s wildfire emissions only 16% above average; otherwise, the year could have set a new record.
Data from the World Resources Institute showed that in 2023, nearly 12 million hectares were burned, about 25% more than the previous record in 2016. Over the past two decades, the area burned by forest fires has increased by roughly 5.4% annually, leading to a loss of nearly 6 million hectares of tree cover each year compared to 2001.
Fires need high temperatures, dry vegetation, and ignition sources to spread. Cutting greenhouse gas emissions is crucial to prevent future wildfires, but improved land management and early warning systems could also help. Measures such as fire bans, creating fire breaks, and managing vegetation can reduce fuel for fires. Providing masks and improving ventilation can mitigate air pollution from fires.
Early warning systems may be limited, as many hot areas face high fire risks throughout the summer. Jones highlighted that wildfires are becoming more frequent and intense due to climate change, affecting both society and the environment. Human-induced climate changes have made fires three times more likely in Canada, twenty times more likely in western Amazonia, and twice as likely in Greece.
With greenhouse gas emissions rising, larger fires are expected in the decade. The research indicates that a Canadian born today is likely to experience another fire of similar magnitude to last year’s inferno within their lifetime, compared to a one in ten chance for someone born in the 1940s.
Even wetlands and rainforests are increasingly at risk due to severe drought. The Pantanal region in Brazil was devastated by record-breaking fires in June, impacting vital wildlife habitats. Although regrowing forests can act as a “delayed carbon sink,” the trend toward more frequent fires is concerning as it reduces the chance for vegetation recovery and increases atmospheric carbon levels.
Jones warned that the shift towards more frequent and severe fires in decade disrupts the natural fire regime, leading to an imbalance where current emissions from fires outweigh the delayed carbon sinks from previous decades.
The State of Wildfires report 2023-24, published in the journal Earth System Science Data, was produced by the University of East Anglia, the UK Centre for Ecology and Hydrology, and the Met Office, with contributions from a global network of researchers and institutions. The report utilized satellite observations, computer models, and regional expertise to compile its findings.
