Global patterns of interannual climate–fire relationships

• Published in: Global change biology Vol. 24; no. 11; pp. 5164 - 5175
• Main Authors: Abatzoglou, John T., Williams, A. Park, Boschetti, Luigi, Zubkova, Maria, Kolden, Crystal A.
• Format: Journal Article
• Language: English
• Published: England Blackwell Publishing Ltd 01.11.2018
• Subjects: Annual variations; Anthropogenic factors; Area; Aridity; Balances (scales); Climate; Climate change; Climate variability; Climatology; Composition; Desiccation; Drying; Earth; ecoregions; fire; Fires; Forests; global; Human factors; Human influences; Humans; Interactions; modeling; Modelling; Models, Theoretical; Rainfall; Regions; Satellites; Seasons; Variability; Vegetation; ecoregions; fire; global; modeling; climate
• ISSN: 1354-1013; 1365-2486
• DOI: 10.1111/gcb.14405

Climate shapes geographic and seasonal patterns in global fire activity by mediating vegetation composition, productivity, and desiccation in conjunction with land‐use and anthropogenic factors. Yet, the degree to which climate variability affects interannual variability in burned area across Earth is less understood. Two decades of satellite‐derived burned area records across forested and nonforested areas were used to examine global interannual climate–fire relationships at ecoregion scales. Measures of fuel aridity exhibited strong positive correlations with forested burned area, with weaker relationships in climatologically drier regions. By contrast, cumulative precipitation antecedent to the fire season exhibited positive correlations to nonforested burned area, with stronger relationships in climatologically drier regions. Climate variability explained roughly one‐third of the interannual variability in burned area across global ecoregions. These results highlight the importance of climate variability in enabling fire activity globally, but also identify regions where anthropogenic and other influences may facilitate weaker relationships. Empirical fire modeling efforts can complement process‐based global fire models to elucidate how fire activity is likely to change amidst complex interactions among climatic, vegetation, and human factors. Understanding how climate factors shape interannual fire variability across diverse landscapes can help improve both near‐term forecasts and long‐term projections of global fire activity. Climate explained about a third of the interannual variability in ecoregion‐level burned area in both forested and nonforested lands from 1997 to 2016. Fuel dryness during the fire season was a strong predictor of burned area in forested regions, particularly in climatologically mesic regions. By contrast, antecedent precipitation strongly correlated with nonforested burned area in semiarid regions.