A global assessment of wildfire potential under climate change utilizing Keetch-Byram drought index and land cover classifications

Abstract

Abstract In recent years, climate change has caused wildfires across the globe to generally become larger and more severe, creating new challenges for public health, housing and infrastructure, and natural resource management. As the characteristics of wildfires change, it is critical to understand where emerging risks for human and natural systems are most profound. We assess how future wildfire potential, defined here as the meteorological conditions and the availability of burnable vegetation types conducive to wildfire occurrence, are projected to change in the future. To achieve this, we combine modelled temperature and precipitation to calculate the Keetch-Byram Drought Index (KBDI) as a proxy for soil moisture deficit and overlay a weighting factor representing burnable vegetation derived from land cover classifications. Through our analysis of daily data at both mid- and end-of-century, we find that climate-related changes, such as increasing temperatures and drying patterns, will elevate wildfire potential globally, both in terms of severity of maximum daily KBDI and frequency of high KBDI days. We find that regions which have recently endured major fire events, including the western United States, Australia, and the Amazon, could experience increases in maximum KBDI of up to 100 in places, with more than 60 additional days of high KBDI by mid-century, compared to the historical baseline. Additionally, at the end-of-the-century, regions across much of Africa, Central America, and Southern Asia are projected to emerge as wildfire hotspots. While the occurrence of wildfires may still be rare today in many regions, we find that climatological trends are projected to increase wildfire potential for much of the globe, creating new risks for some, and raising the challenge for already wildfire-prone communities to effectively manage forests and protect people and critical resources.