Abstract
Climate change is increasing the frequency and intensity of extreme wildfires globally, yet our understanding of these high-impact events remains uneven and shaped by media attention and regional research biases. The State of Wildfires project systematically tracks global and regional fire activity of each annual fire season, analyses the causes of prominent extreme wildfire events, and projects the likelihood of similar events occurring in future climate scenarios. This, its second annual report, covers the March 2024 to February 2025 fire season. During the 2024–2025 fire season, fire-related carbon (C) emissions totalled 2.2 Pg C, 9 % above average and the sixth highest on record since 2003, despite below-average global burned area (BA). Extreme fire seasons in South America’s rainforests, dry forests, and wetlands and in Canada’s boreal forests pushed up the global C emissions total. Fire C emissions were over 4 times above average in Bolivia, 3 times above average in Canada, and ∼ 50 % above average in Brazil and Venezuela. Wildfires in 2024–2025 caused 100 fatalities in Nepal, 34 in South Africa, and 31 in Los Angeles, with additional fatalities reported in Canada, Côte d’Ivoire, Portugal, and Türkiye. The Eaton and Palisades fires in Southern California caused 150 000 evacuations and USD 140 billion in damages. Communities in Brazil, Bolivia, Southern California, and northern India were exposed to fine particulate matter at concentrations 13–60 times WHO’s daily air quality standards. We evaluated the causes and predictability of four extreme wildfire episodes from the 2024–2025 fire season, including in Northeast Amazonia (January–March 2024), the Pantanal–Chiquitano border regions of Brazil and Bolivia (August–September 2024), Southern California (January 2025), and the Congo Basin (July–August 2024). Anomalous weather created conditions for these regional extremes, while fuel availability and human ignitions shaped spatial patterns and temporal fire dynamics. In the three tropical regions, prolonged drought was the dominant fire enabler, whereas in California, extreme heat, wind, and antecedent fuel build-up were compounding enablers. Our attribution analyses show that climate change made extreme fire weather in Northeast Amazonia 30–70 times more likely, increasing BA roughly 4-fold compared to a scenario without climate change. In the Pantanal–Chiquitano, fire weather was 4–5 times more likely, with 35-fold increases in BA. Meanwhile, our analyses suggest that BA was 25 times higher in Southern California due to climate change. The Congo Basin’s fire weather was 3–8 times more likely with climate change, with a 2.7-fold increase in BA. Socioeconomic changes since the pre-industrial period, including land-use change, also likely increased BA in Northeast Amazonia. Our models project that events on the scale of 2024–2025 will become up to 57 %, 34 %, and 50 % more frequent than in the modern era in Northeast Amazonia, the Pantanal–Chiquitano, and the Congo Basin, respectively, under a medium–high scenario (SSP370) by 2100. Climate action can limit the added risk, with frequency increases held to below 15 % in all three regions under a strong mitigation scenario (SSP126). In Southern California, the future trajectory of extreme fire likelihood remains highly uncertain due to poorly constrained climate–vegetation–fire interactions influencing fuel moisture, though our models suggest that risk may decline in future. This annual report from the State of Wildfires project integrates and advances cutting-edge fire observations and modelling with regional expertise to track changing global wildfire hazard, guiding policy and practice towards improved preparedness, mitigation, adaptation, and societal benefit. Thirteen new datasets and model codebases presented in this work are available from the State of Wildfires Project’s Zenodo community, including updated annual statistics on wildfire extent (Jones et al., 2025; https://doi.org/10.5281/zenodo.15525674), outputs from modelling of fire causality using PoF model (Di Giuseppe, 2025; https://doi.org/10.24433/CO.8570224.v1) and codebase for the extreme event attribution/projections model, ConFLAME (Barbosa et al., 2025a, https://doi.org/10.5281/zenodo.16790787).
| Original language | English |
|---|---|
| Pages (from-to) | 5377-5488 |
| Number of pages | 112 |
| Journal | Earth System Science Data |
| Volume | 17 |
| Issue number | 10 |
| DOIs | |
| Publication status | Published - 16 Oct 2025 |
Bibliographical note
Open access CC-BYFunding
Douglas I. Kelley and Maria L. F. Barbosa were funded by the UK Natural Environment Research Council (NERC) as part of the LTSM2 TerraFIRMA project and NC-International programme (grant no. NE/X006247/1) delivering National Capability. Chantelle Burton and Emily Wright were funded by the UK Department for Science (DSIT) Met Office Hadley Centre Climate Programme and the DSIT Innovation and Technology International Science Partnerships Fund (ISPF; UK Met Office Climate Science for Service Partnership (CSSP) Brazil). Francesca Di Giuseppe and Joe R. McNorton were funded by a service contract (no. 942604) issued by the Joint Research Center on behalf of the European Commission. Matthew W. Jones was funded by the UK NERC (NE/V01417X/1). Anna S. I. Bradley was funded by the DSIT Innovation and Technology International Science Partnerships Fund (ISPF; UK Met Office Climate Science for Service Partnership (CSSP) Brazil). Carmen B. Steinmann was funded by the Swiss Innovation Agency Innosuisse (grant no. 120.464 IP-SBM). Elena A. Kukavskaya was funded by the State Assignment Project (grant no. FWES-2024-0040). Esther Brambleby was funded by the UK NERC ARIES Doctoral Training Partnership (grant no. NE/S007334/1). Guilherme Mataveli was funded by the FAPESP (grant nos. 2019/25701-8 and 2023/03206-0). Hamish Clarke was funded by the Westpac Scholars Trust via a Westpac Research Fellowship and by the Australian Research Council via an Industry Fellowship with the Victorian Department of Energy, Environment, and Climate Action, the Victorian Country Fire Authority and Natural Hazards Research Australia (grant no. IM240100046). Jakob B. Wessel was funded by the UK Engineering and Physical Sciences Research Council (EPSRC; 2696930). Liana O. Anderson was funded by the São Paulo Research Foundation (FAPESP; 2021/07660-2 and 2020/16457-3) and the Brazilian National Council for Scientific and Technological Development (CNPq; 409531/2021-9 and 314473/2020-3). Miguel Ángel Torres-Vázquez and Marco Turco were funded by the Spanish Ministry of Science and Innovation (MCIN; MCIN/AEI/10.13039/501100011033; ONFIRE PID2021-123193OB-I00) and by the European Regional Development Fund (ERDF; project “A way of making Europe”). Mark Parrington and Enza Di Tomaso are part of the Copernicus Atmosphere Monitoring Service, which is operated by the European Centre for Medium-Range Weather Forecasts (ECMWF) on behalf of the European Commission as part of the Copernicus Programme. Marco Turco was funded by the Spanish Ministry of Science, Innovation and Universities through the Ramón y Cajal (grant no. RYC2019-027115-I). Paulo M. Fernandes was supported by the Portuguese Foundation for Science and Technology (FCT; UID/04033/2025 (Centre for the Research and Technology of Agro-Environmental and Biological Sciences) and LA/P/0126/2020, 10.54499/LA/P/0126/2020 ). Renata Veiga was funded by the Brazilian National Council for Scientific and Technological Development (CNPq; #443285/2023-3) and the Brazilian Institute of Environment and Renewable Natural Resources (IBAMA)/Federal University of Rio de Janeiro (UFRJ; #968711). Sarah Meier was funded by the Dragon Capital Chair on Biodiversity Economics. Sander Veraverbeke and Yuquan Qu were funded by a European Research Council Consolidator Grant (grant no. 101000987). Theodore R. Keeping was funded by Schmidt Sciences, LLC. Galia Selaya was funded within the PRODIGY project by the BMFTR (grant no. 01LC2324) and the Fulbright Amazonia programme (sponsored by the U.S. Department of State and the Fulbright Commission in Brazil). The authors thank all contributing panellists of the regional expert panels (Table A1): Lucy Amissah, Dolors Armenteras, Davide Ascoli, Sally Archibald, Francisco de la Barrera, Stefan Doerr, Mauro Gonzalez, Chelene Hanes, Piyush Jain, Matt Jolly, Natasha Ribeiro, Julien Ruffault, Bambang Saharjo, Sundar Sharma, Celso Silva Junior, Jacqueline Shuman, Tercia Strydom, Raman Sukumar, Veerachai Tanpipat, Gavriil Xanthopoulos, and Bo Zheng. The regional panel of Oceania thank the following for their contributions to the identification and description of key events in the 2024–2025 fire season: Telmo António, Chris Collins, David Field, Rui Feix, Russell Stephens Peacock, Grant Pearce, Simeon Telfer, and Maggie Towers. We thank the working groups “FLARE: Fire science Learning AcRoss the Earth System” and “TerraFIRMA: Dummies Guide to using Fire Models” for contributing to defining the report scope and establishing contributor links. We thank Luca Minello for his assistance with the analyses of C project exposure to fire. We thank the CNDFB (Comité National de Défense de la Forêt et de lutte contre les Feux de Brousse) for their contribution to the characterisation of the fire season in West Africa. We acknowledge the use of GrammarlyGO (http://www.grammarly.com, last access: 6 August 2025) and ChatGPT-4 (https://chatgpt.com/, last access: 6 August 2025) to identify improvements in language use and writing style only of an earlier draft.
| Funders | Funder number |
|---|---|
| Natural Environment Research Council | NE/X006247/1, NE/S007334/1 |
| Department for Science, Innovation and Technology | |
| European Commission | NE/V01417X/1 |
| Innosuisse - Schweizerische Agentur für Innovationsförderung | 120.464 IP-SBM, FWES-2024-0040 |
| Fundação de Amparo à Pesquisa do Estado de São Paulo | 2020/16457-3, 2023/03206-0, 2021/07660-2, 2019/25701-8 |
| Westpac Scholars Trust | |
| Australian Research Council | |
| Engineering and Physical Sciences Research Council | 2696930 |
| Conselho Nacional de Desenvolvimento Científico e Tecnológico | 409531/2021-9, 314473/2020-3 |
| Ministry of Science, Innovation and Universities | |
| Fundação para a Ciência e a Tecnologia | UID/04033/2025 |
| Bundesministerium für Forschung, Technologie und Raumfahrt | 01LC2324 |
| US Department of State | |
| US Department of State | |
| Dragon Capital | |
| Schmidt Sciences | |
| Fulbright Commission Brazil |
UN SDGs
This output contributes to the following UN Sustainable Development Goals (SDGs)
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SDG 13 Climate Action
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SDG 15 Life on Land
Themes
- Climate and Environmental Change
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