Global warming has rapidly increased the risk of dangerous wildfires in several ways. Warmer temperatures dry out trees, brush and grass, enabling vegetation to burn more readily and spread faster after a fire ignites. Research also shows that global warming has lengthened the wildfire season substantially in many regions. The combined result is that fires are bigger, hotter and burning faster in areas and seasons where they were once rare.
Nerilie Abram, a climate extremes researcher with Australian National University and the Australian Centre of Excellence for Climate Extremes, says there is also evidence that global warming is raising regional wildfire risks in ways that aren’t captured by direct attribution studies. The warming of the oceans is shifting the path of rainy storms away from southern Australia, she said, resulting in a regional drying trend that makes fires more likely.