Speaker
Description
One of the most visible ways humans are affecting the environment is our modification of wildfires. Nearly every type of human activity influences wildfires, including agriculture, spreading invasive species, and changing the climate, creating serious consequences for human societies and their environment. However, predicting fire interactions with land use, management, and climate change, remains challenging and represents a serious knowledge gap and vulnerability. In our study, we surveyed 98 wildfire researchers from around the globe for a holistic assessment of how fire regimes are changing and what this could mean for human society, global biodiversity, and climate change. 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 wildfire 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 regimes 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.
