Climate change raised the odds of unprecedented wildfires in 2023-24
The Inaugural ‘State of Wildfires’ Report report, published in the journal Earth System Science Data (ESSD), offers a comprehensive analysis of global wildfires, supported by data from the Copernicus Atmosphere Monitoring Service (CAMS). The report provides crucial insights into extreme fire events, their causes, predictability, and the role of anthropogenic factors, and the findings highlight the essential role of scientific data in informing policy and improving resilience. The report shows that if there is no action to tackle greenhouse gases now, wildfires similar in scale to the 2023-24 season will become over six times more common in Canada by 2100, and twice as common under a low emissions scenario.
Highlights:
- Fueled by climate change and human activity, a series of wildfires shattered records for burned areas and carbon emissions across the globe in 2023-2024, leaving a lasting impact on ecosystems, air quality, and communities.
- The 2023-2024 global fire season saw unprecedented wildfire activity in several regions, particularly in Canada.
- Approximately 3.9 million square kilometers burned globally during the 2023-2024 fire season; this ranks 12th among the 22 fire seasons since 2002. However, despite the lower-than-average burned area, fire carbon emissions were 16 percent above average and ranked seventh-highest since 2003.
- The “most prominent global anomaly” occurred in Canada, which experienced its worst fire season on record during the study period. The country’s burned areas reached six times the average of previous fire seasons and fire carbon emissions reached nine times the average.
- More than 150,000 square kilometers burned across Canada, and Canadian forests contributed 24 percent of global fire carbon emissions in the period, up from an average of 3 percent in previous years.
- Wildfires in Canada also had a global impact, affecting air quality in major cities across North America, including New York City, which experienced its worst air quality in decades.
- The odds that Canada will experience another scenario similar to June 2023 is expected to increase from 0.15 percent annually in the 2010s to 0.42 percent to 2.2 percent by the 2040s across scenarios. Under a high emissions scenario, this likelihood could reach 2.1 to 3.7 percent by 2100.
San Francisco, CA (Aug. 14, 2024) – Unprecedented wildfires in Canada and parts of Amazonia last year were at least three times more likely due to climate change and contributed to high levels of carbon dioxide (CO2) emissions from burning globally, according to the first edition of a new systematic review.
The State of Wildfires report takes stock of extreme wildfires of the 2023-2024 fire season (March 2023-February 2024), explains their causes, and assesses whether events could have been predicted. It also evaluates how the risk of similar events will change in future under different climate change scenarios.
The report, which will be published annually, is co-led by the University of East Anglia (UEA, UK), the UK Centre for Ecology & Hydrology (UKCEH), the Met Office (UK) and European Centre for Medium-Range Weather Forecasts (ECMWF, UK).
If it had not been a quiet fire season in the African savannahs, then the 2023-24 fire season would have set a new record for CO2 emissions from fires globally.
State of Wildfires 2023–2024 report
Published in the journal Earth System Science Data, the report finds that carbon emissions from wildfires globally were 16% above average, totalling 8.6 billion tonnes of carbon dioxide. Emissions from fires in the Canadian boreal forests were over nine times the average of the past two decades and contributed almost a quarter of the global emissions.
If it had not been a quiet fire season in the African savannahs, then the 2023-24 fire season would have set a new record for CO2 emissions from fires globally.
As well as generating large CO2 emissions, fires in Canada led to more than 230,000 evacuations and eight firefighters lost their lives. An unusually high number of fires were also seen in northern parts of South America, particularly in Brazil’s Amazonas state and in neighbouring areas of Bolivia, Peru, and Venezuela. This led to the Amazon region experiencing among the worst air quality ratings on the planet.
Elsewhere in the world, individual wildfires that burned intensely and spread quickly in Chile, Hawaii, and Greece led to 131, 100, and 19 direct fatalities, respectively. These were among the many wildfires worldwide with significant impacts on society, the economy, and the environment.
“Last year, we saw wildfires killing people, destroying properties and infrastructure, causing mass evacuations, threatening livelihoods, and damaging vital ecosystems,” said the lead author of this year’s analysis, Dr Matthew Jones, Research Fellow at the Tyndall Centre for Climate Change Research at UEA.
“Wildfires are becoming more frequent and intense as the climate warms, and both society and the environment are suffering from the consequences.”
The loss of carbon stocks from boreal forests in Canada and tropical forests in South America have lasting implications for the Earth’s climate. Forests take decades to centuries to recover from fire disturbance, meaning that extreme fire years such as 2023-24 result in a lasting deficit in carbon storage for many years to come.
“In Canada, almost a decade’s worth of carbon emissions from fire were recorded in a single fire season – more than 2 billion tonnes of CO2,” said Dr Jones. “In turn, this raises atmospheric concentrations of CO2 and exacerbates global warming.”
Climate change made the 2023-24 fire season more extreme
As well as cataloguing high-impact fires globally, the report focused on explaining the causes of extreme fire extent in three regions: Canada, western Amazonia, and Greece.
Fire weather – characterised by hot, dry conditions that promote fire – has shifted significantly in all three focal regions when compared to a world without climate change. Climate change made the extreme fire-prone weather of 2023-24 at least three times more likely in Canada, 20 times more likely in Amazonia, and twice as likely in Greece.
The report also used cutting-edge attribution tools to distinguish how climate change has altered the area burned by fires versus a world without climate change. It found that the vast extent of wildfires in Canada and Amazonia in the 2023-24 fire season was almost certainly greater due to climate change (with more than 99% confidence).
“It is virtually certain that fires were larger during the 2023 wildfires in Canada and Amazonia due to climate change,” said Dr Chantelle Burton, Senior Climate Scientist at the Met Office.
“We are already seeing the impact of climate change on weather patterns all over the world, and this is disrupting normal fire regimes in many regions. It is important for fire research to explore how climate change is affecting fires, which gives insights into how they may change further in the future.”
Likelihood of extreme wildfires will rise but can be mitigated
Climate models used in the report suggest that the frequency and intensity of extreme wildfires will increase by the end of the century, particularly in future scenarios where greenhouse gas emissions remain high.
The report shows that by 2100, under a mid-to-high greenhouse gas emissions scenario (SSP370), wildfires similar in scale to the 2023-24 season will become over six times more common in Canada. Western Amazonia could see an extreme fire season like 2023-24 almost three times more frequently. Similarly, years with fires on the scale of those seen in Greece during 2023-2024 are projected to double in frequency.
“As long as greenhouse gas emissions continue to rise, the risk of extreme wildfires will escalate,” said Dr Douglas Kelley, Senior Fire Scientist at UKCEH.
Increases in the future likelihood of extreme wildfire events, on the scale of 2023-2024, can be minimised by reducing greenhouse gas emissions. Following a low emissions scenario (SSP126) can limit the future likelihood of extreme fires. In western Amazonia, the frequency of events like 2023-24 is projected to be no larger in 2100 than in the current decade under a low emissions scenario. In Canada, the future increase in frequency of extreme fires is reduced from a factor of six to a factor of two, while in Greece the increase is limited to 30%.
“Whatever emissions scenario we follow, risks of extreme wildfires will increase in Canada, highlighting that society must not only cut emissions but also adapt to changing wildfire risks,” said Dr Kelley.
“These projections highlight the urgent need to rapidly reduce greenhouse gas emissions and manage vegetation in order to reduce the risk and impacts of increasingly severe wildfires on society and ecosystems.”
Disentangling the causes of extreme fires
Several factors control fire, including weather conditions influenced by climate change, the density of vegetation on the landscape influenced by climate and land management, and ignition opportunities influenced by people and lightning.
Disentangling the influence of these factors can be complex, but the report used cutting-edge fire models to reveal the influence of different factors on extreme fire activity.
The report found that the area burned by fires in Canada and Greece would likely have been larger if the landscape had not been altered by people. Activities such as agriculture, forestry, and dedicated fire management efforts all influence the landscape, and can reduce the density of vegetation. In addition, firefighters also help to reduce fire spread by tackling active wildfires. When wildfires meet areas with sparse vegetation or more aggressive firefighting strategies, they can run out of fuel or be contained.
“In Canada and Greece, a mix of severe fire weather and plenty of dry vegetation reinforced one another to drive a major uptick in the number and extent of fires last year,” said Dr Francesca Di Giuseppe, Senior Scientist at ECMWF.
She added: “But our analysis also shows that factors such as suppression and landscape fragmentation related to human activities likely played important roles in limiting the final extent of the burned areas.
“Human practices played an important role in the most extreme events we analysed. However, we found that the final extent of these fires was determined by the simultaneous occurrence of multiple predictable factors — principally weather, fuel abundance, and moisture — rather than direct human influence.”
The report found that human activities increased the extent of the 2023 wildfires in western Amazonia. In this region, the expansion of agriculture has resulted in widespread deforestation and forest degradation. This has left forests more vulnerable to fire during periods of drought and fire weather, amplifying the effect of climate change.
During 2023-24, the fourth most powerful El Niño event on record drove a prolonged drought and heatwave in South America. This natural feature of Earth’s climate increases temperatures and reduces rainfall in Amazonia every three to eight years, but it is increasingly superimposed on higher temperatures due to climate change.
“In many tropical forests like Amazonia, deforestation and the expansion of agriculture have exacerbated the effects of climate change on wildfire risk, leaving these vital ecosystems more vulnerable,” said Dr Burton.
An eye towards the 2024-2025 fire season
Forecasting fire risk is a growing research area and early warning systems have already been built based on weather factors alone. For example, in Canada, extreme fire weather was predicted two months in advance and provided early indications of high fire potential in 2023. Events in Greece and Amazonia had shorter windows of predictability.
For the 2024-25 season, forecasts suggested a continued above-average likelihood of fire weather – hot, dry, and windy conditions – in parts of North and South America, which presented favourable conditions for wildfires in California, Alberta, British Columbia, and in the Brazilian Pantanal in June and July.
Dr Di Giuseppe said: “We’re not particularly surprised by some of the recent fires in the news, as above-average fire weather was predicted in parts of North and South America. However, the extensive Arctic fires we’ve witnessed recently have caught us by surprise — something to look at in our next report.”
To accompany the report, an interactive atlas and timeseries chart have been created, showing extremes of the 2023-2024 fire season by country and by burned area, CO2 emissions, and number of fires.
State of Wildfires interactive map
The State of Wildfires 2023-2024 report focuses on extreme and impactful wildfires of the latest fire season.
Use this interactive map and chart to explore anomalies in fire count, burned area, emissions, fire size, and fire rate of growth in the 2023-24 fire season, versus previous fire seasons since 2002. They show regional extreme values in five key metrics of fire season extremity during the 2023-2024 fire season, compared with previous fire seasons since 2002. The mapped data includes departures in each metric from their average values, showing how they vary spatially or through time.
Abstract
Climate change contributes to the increased frequency and intensity of wildfires globally, with significant impacts on society and the environment. However, our understanding of the global distribution of extreme fires remains skewed, primarily influenced by media coverage and regionalised research efforts. This inaugural State of Wildfires report systematically analyses fire activity worldwide, identifying extreme events from the March 2023–February 2024 fire season. We assess the causes, predictability, and attribution of these events to climate change and land use and forecast future risks under different climate scenarios. During the 2023–2024 fire season, 3.9×106 km2 burned globally, slightly below the average of previous seasons, but fire carbon (C) emissions were 16 % above average, totalling 2.4 Pg C. Global fire C emissions were increased by record emissions in Canadian boreal forests (over 9 times the average) and reduced by low emissions from African savannahs. Notable events included record-breaking fire extent and emissions in Canada, the largest recorded wildfire in the European Union (Greece), drought-driven fires in western Amazonia and northern parts of South America, and deadly fires in Hawaii (100 deaths) and Chile (131 deaths). Over 232 000 people were evacuated in Canada alone, highlighting the severity of human impact. Our analyses revealed that multiple drivers were needed to cause areas of extreme fire activity. In Canada and Greece, a combination of high fire weather and an abundance of dry fuels increased the probability of fires, whereas burned area anomalies were weaker in regions with lower fuel loads and higher direct suppression, particularly in Canada. Fire weather prediction in Canada showed a mild anomalous signal 1 to 2 months in advance, whereas events in Greece and Amazonia had shorter predictability horizons. Attribution analyses indicated that modelled anomalies in burned area were up to 40 %, 18 %, and 50 % higher due to climate change in Canada, Greece, and western Amazonia during the 2023–2024 fire season, respectively. Meanwhile, the probability of extreme fire seasons of these magnitudes has increased significantly due to anthropogenic climate change, with a 2.9–3.6-fold increase in likelihood of high fire weather in Canada and a 20.0–28.5-fold increase 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 (SSP370). This report represents our first annual effort to catalogue extreme wildfire events, explain their occurrence, and predict future risks. By consolidating state-of-the-art wildfire science and delivering key insights relevant to policymakers, disaster management services, firefighting agencies, and land managers, we aim to enhance society’s resilience to wildfires and promote advances in preparedness, mitigation, and adaptation.
About Earth System Science Data
Earth System Science Data (ESSD) is an international, interdisciplinary journal for the publication of articles on original research data (sets), furthering the reuse of high-quality data of benefit to Earth system sciences. The editors encourage submissions on original data or data collections which are of sufficient quality and have potential to contribute to these aims. The journal maintains sections for regular-length articles, brief communications (e.g. on additions to data sets) and commentaries, as well as review articles and special issues. For more information, please visit climate.copernicus.eu.
About Copernicus
Copernicus is the European Union’s flagship Earth observation programme which operates through six thematic services: Atmosphere, Marine, Land, Climate Change, Security and Emergency. It delivers freely accessible operational data and services providing users with reliable and up-to-date information related to our planet and its environment. The programme is coordinated and managed by the European Commission and implemented in partnership with the Member States, the European Space Agency (ESA), the European Organisation for the Exploitation of Meteorological Satellites (EUMETSAT), the European Centre for Medium-Range Weather Forecasts (ECMWF), EU Agencies and Mercator Océan, amongst others. For more information, please visit climate.copernicus.eu.
About ECMWF
ECMWF operates two services from the EU’s Copernicus Earth observation programme: the Copernicus Atmosphere Monitoring Service (CAMS) and the Copernicus Climate Change Service (C3S). They also contribute to the Copernicus Emergency Management Service (CEMS). The European Centre for Medium-Range Weather Forecasts (ECMWF) is an independent intergovernmental organisation supported by 34 states. It is both a research institute and a 24/7 operational service, producing and disseminating numerical weather predictions to its Member States. This data is fully available to the national meteorological services in the Member States. The supercomputer facility (and associated data archive) at ECMWF is one of the largest of its type in Europe and Member States can use 25% of its capacity for their own purposes.
SOURCE: Copernicus Climate Change Service
Tags: climate change, Copernicus, report, wildfires