Brigham Young University (BYU), Institute of Plant Sciences, University of Bern, Laboratoire Chrono-environnement (UMR 6249) (LCE), Centre National de la Recherche Scientifique (CNRS)-Université de Franche-Comté (UFC), Université Bourgogne Franche-Comté [COMUE] (UBFC)-Université Bourgogne Franche-Comté [COMUE] (UBFC), Maison des Sciences de l'Homme et de l'Environnement Claude Nicolas Ledoux (UAR 3124) (MSHE), Oeschger Centre for Climate Change Research (OCCR), Institute of Geography and Spatial Organization, Polish Academy of Sciences, Gembloux Agro-Bio Tech [Gembloux], Université de Liège, Département de géographie, Université de Montréal, Montréal, Canada, Senckenberg biodiversität und klima forschungszentrum (BIK-F), Forschungsinstitut Senckenberg (SGN), University of Turku, Helsingin yliopisto = Helsingfors universitet = University of Helsinki, University of Tasmania [Hobart, Australia] (UTAS), Scientific Research Centre of the Slovenian Academy of Sciences and Arts (ZRC SAZU), Université du Québec en Abitibi-Témiscamingue (UQAT), University of Liverpool, Institut des Sciences de l'Evolution de Montpellier (UMR ISEM), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-École Pratique des Hautes Études (EPHE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Montpellier (UM)-Institut de recherche pour le développement [IRD] : UR226-Centre National de la Recherche Scientifique (CNRS), Institut méditerranéen de biodiversité et d'écologie marine et continentale (IMBE), Avignon Université (AU)-Aix Marseille Université (AMU)-Institut de recherche pour le développement [IRD] : UMR237-Centre National de la Recherche Scientifique (CNRS)
Human activity has fundamentally altered wildfire on Earth, creating serious consequences for human health, global biodiversity, and climate change. However, it remains difficult to predict fire interactions with land use, management, and climate change, representing a serious knowledge gap and vulnerability. We used expert assessment to combine opinions about past and future fire regimes from 98 wildfire researchers. We asked for quantitative and qualitative assessments of the frequency, type, and implications of fire regime change from the beginning of the Holocene through the year 2300. Respondents indicated that direct human activity was already influencing wildfires locally since at least ~12,000 years BP, though natural climate variability remained the dominant driver of fire regime until around 5000 years BP. Responses showed a ten-fold increase in the rate of wildfire regime change during the last 250 years compared with the rest of the Holocene, corresponding first with the intensification and extensification of land use and later with anthropogenic climate change. Looking to the future, fire regimes were predicted to intensify, with increases in fire frequency, severity, and/or size in all biomes except grassland ecosystems. Fire regime showed quite different climate sensitivities across biomes, but the likelihood of fire regime change increased with higher greenhouse gas emission scenarios for all biomes. Biodiversity, carbon storage, and other ecosystem services were predicted to decrease for most biomes under higher emission scenarios. We present recommendations for adaptation and mitigation under emerging fire regimes, concluding that management options are seriously constrained under higher emission scenarios.Competing Interest StatementThe authors have declared no competing interest. Introduction Methods and materials Results and discussion Timing and type of future fire regime change Consequences of fire regime change Our capacity to prevent, control, or adapt to future fire regimes Charting a course in a world of uncertainty Expert assessment application in fire management
