Wildfires are an important component of terrestrial ecosystem ecology but also a major natural hazard to societies, and their frequency and spatial distribution must be better understood1. At a given location, risk from wildfire is associated with the annual fraction of burned area, which is expected to increase in response to climate warming1,2,3. Until recently, however, only a few global studies of future fire have considered the effects of other important global environmental change factors such as atmospheric CO2 levels and human activities, and how these influence fires in different regions4,5. Here, we contrast the impact of climate change and increasing atmospheric CO2 content on burned area with that of demographic dynamics, using ensembles of climate simulations combined with historical and projected population changes under different socio-economic development pathways for 1901–2100. Historically, humans notably suppressed wildfires. For future scenarios, global burned area will continue to decline under a moderate emissions scenario, except for low population growth and fast urbanization, but start to increase again from around mid-century under high greenhouse gas emissions. Contrary to common perception, we find that human exposure to wildfires increases in the future mainly owing to projected population growth in areas with frequent wildfires, rather than by a general increase in burned area.
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A.A. and W.K. acknowledge support from the EU FP7 projects PEGASOS (265148) and LUC4C (603542). A.A. also acknowledges support from the Helmholtz Association in the ATMO programme and through its Innovation and Networking fund. W.K. thanks A. Ahlström for providing gridded driving data from the CMIP5 simulations.
The authors declare no competing financial interests.
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Knorr, W., Arneth, A. & Jiang, L. Demographic controls of future global fire risk. Nature Clim Change 6, 781–785 (2016). https://doi.org/10.1038/nclimate2999
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