Assessing changes in global fire regimes
Sayedeh Sara Sayedi, Benjamin W. Abbott, Boris Vannière, Bérangère Leys, Danièle Colombaroli, Graciela Gil‐Romera, Michał Słowiński, Julie C. Aleman, Olivier Blarquez, Angelica Feurdean, Kendrick J. Brown, Tuomas Aakala, Teija Alenius, Kathryn Allen, Maja Andrič, Yves Bergeron, Siria Biagioni, Richard Bradshaw, Laurent Brémond, Élodie Brisset, Joseph Brooks, Sandra O. Brugger, Thomas Brussel, Haidee Cadd, Eleonora Cagliero, Christopher Carcaillet, Vachel A. Carter, Filipe X. Catry, Antoine Champreux, Émeline Chaste, Raphaël D. Chavardès, M. L. Chipman, Marco Conedera, Simon Connor, Mark Constantine, Colin J. Courtney Mustaphi, Abraham Dabengwa, William Daniels, Erik de Boer, Elisabeth Dietze, Joan Estrany, Paulo M. Fernandes, Walter Finsinger, Suzette G. A. Flantua, Paul Fox‐Hughes, Dorian M. Gaboriau, Eugenia M. Gayó, Martin P. Girardin, Jeffrey Glenn, Ramesh Glückler, Catalina González, Mariangelica Groves, Douglas S. Hamilton, Rebecca Hamilton, Stijn Hantson, Kartika Anggi Hapsari, Mark Hardiman, Donna Hawthorne, Kira M. Hoffman, Jun Inoue, Allison T. Karp, Patrik Krebs, Charuta Kulkarni, Niina Kuosmanen, Terri Lacourse, Marie‐Pierre Ledru, Marion Lestienne, Colin J. Long, José Antonio López Sáez, Nicholas J.D. Loughlin, Mats Niklasson, Javier Madrigal, S. Yoshi Maezumi, Katarzyna Marcisz, Michela Mariani, David B. McWethy, Grant A. Meyer, Chiara Molinari, Encarni Montoya, Scott Mooney, César Morales‐Molino, J.L. Morris, Patrick Moss, Imma Oliveras Menor, José M. C. Pereira, Gianni Boris Pezzatti, Nadine Pickarski, Roberta Pini, Emma Rehn, Cécile C. Remy, Jordi Revelles, Damien Rius, Vincent Robin, Yanming Ruan, Natalia Rudaya, Jeremy Russell‐Smith, Heikki Seppä, Lyudmila Shumilovskikh, William T. Sommers, Çağatay Tavşanoğlu
Abstract
Abstract Background The global human footprint has fundamentally altered wildfire regimes, creating serious consequences for human health, biodiversity, and climate. However, it remains difficult to project how long-term interactions among land use, management, and climate change will affect fire behavior, representing a key knowledge gap for sustainable management. We used expert assessment to combine opinions about past and future fire regimes from 99 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. Results Respondents indicated some direct human influence on wildfire since at least ~ 12,000 years BP, though natural climate variability remained the dominant driver of fire regime change until around 5,000 years BP, for most study regions. Responses suggested a ten-fold increase in the frequency of fire 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 frequency, severity, and size in all biomes except grassland ecosystems. Fire regimes showed different climate sensitivities across biomes, but the likelihood of fire regime change increased with higher warming 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, while recognizing that management options are constrained under higher emission scenarios. Conclusion The influence of humans on wildfire regimes has increased over the last two centuries. The perspective gained from past fires should be considered in land and fire management strategies, but novel fire behavior is likely given the unprecedented human disruption of plant communities, climate, and other factors. Future fire regimes are likely to degrade key ecosystem services, unless climate change is aggressively mitigated. Expert assessment complements empirical data and modeling, providing a broader perspective of fire science to inform decision making and future research priorities.