Climate change and disruptions to global fire activity

Abstract

Abstract. Future disruptions to fire activity will threaten ecosystems and human well-being throughout the world, yet there are few fire projections at global scales and almost none from a broad range of global climate models (GCMs). Here we integrate global fire datasets and environmental covariates to build spatial statistical models of fire probability at a 0.58 resolution and examine environmental controls on fire activity. Fire models are driven by climate norms from 16 GCMs (A2 emissions scenario) to assess the magnitude and direction of change over two time periods, 2010-2039 and 2070-2099. From the ensemble results, we identify areas of consensus for increases or decreases in fire activity, as well as areas where GCMs disagree. Although certain biomes are sensitive to constraints on biomass productivity and others to atmospheric conditions promoting combustion, substantial and rapid shifts are projected for future fire activity across vast portions of the globe. In the near term, the most consistent increases in fire activity occur in biomes with already somewhat warm climates; decreases are less pronounced and concentrated primarily in a few tropical and subtropical biomes. However, models do not agree on the direction of nearterm changes across more than 50% of terrestrial lands, highlighting major uncertainties in the next few decades. By the end of the century, the magnitude and the agreement in direction of change are projected to increase substantially. Most far-term model agreement on increasing fire probabilities (;62%) occurs at mid-to high-latitudes, while agreement on decreasing probabilities (;20%) is mainly in the tropics.Although our global models demonstrate that long-term environmental norms are very successful at capturing chronic fire probability patterns, future work is necessary to assess how much more explanatory power would be added through interannual variation in climate variables. This study provides a first examination of global disruptions to fire activity using an empirically based statistical framework and a multi-model ensemble of GCM projections, an important step toward assessing fire-related vulnerabilities to humans and the ecosystems upon which they depend.

The status and challenge of global fire modelling

“…Statistical models have been used to examine the potential trajectory of changes in fire during the 21st century (e.g. Moritz et al, 2012;Settele et al, 2014). Such models essentially assess the possibility of fire occurring given climate conditions and fuel availability (fire risk or fire danger) based on modern-day relationships between climate, fuel, and some aspects of the fire regime such as burnt area.…”

Impact of anthropogenic climate change on wildfire across western US forests

“…The strong interannual correlation between forest fire activity and fire-season fuel aridity, as well as observed increases in vapor pressure deficit (VPD) (9), fire danger indices (10), and climatic water deficit (CWD) (11) over the past several decades, present a compelling argument that climate change has contributed to the recent increases in fire activity. Previous studies have implicated anthropogenic climate change (ACC) as a contributor to observed and projected increases in fire activity globally and in the western United States (12)(13)(14)(15)(16)(17)(18)(19), yet no studies have quantified the degree to which ACC has contributed to observed increases in fire activity in western US forests.…”

Abiotic and Biotic Soil Characteristics in Old Growth Forests and Thinned or Unthinned Mature Stands in Three Regions of Oregon

“…Frequent, gentle fires would consume litter, lower carbon inputs to soil, and, because of their frequency tend to homogenize soil organic matter across landscapes by preventing large buildups of dead organic matter aboveground. The high diversity among mature stands of the Siskiyous is not possible to relate to management, as those stands originated from severe wild fires set by EuroAmercans, an unfortunate combination of unnatural and unmanaged, and a situation that may not be uncommon if, as predicted, climate change results in more frequent, severe wildfires [69].…”