An assessment of the viability of prescribed burning as a management tool under a changing climate: a Tasmanian case study

Fire danger is projected to increase across Tasmania under climate change, with the fire season starting earlier and lasting longer. Prescribed burning is currently the only effective method of managing bushfire risk at the landscape scale in Tasmania. It is generally carried out during autumn and spring, when weather conditions allow low intensity burns to be safely managed. We investigated the changing opportunities for prescribed burning in Tasmania in the near future (2021-2040) and towards the end of the century (2081-2100) under a high emissions scenario (SRES A2). We assessed monthly changes in the climate variables that determine when prescribed burning can be applied, including rainfall, temperature, fuel moisture and atmospheric stability. We found that in the future, weather conditions conducive to safe, low intensity burning may occur less frequently. Increased Drought Factor and Soil Dryness Index in spring and autumn, resulting from rising temperatures and reduced rainfall, may result in increased fuel availability. These trends become evident in the near future (2021-2040), followed by substantial changes by the end of the century (2081-2100). This suggests a significant reduction in the ability to safely conduct and contain prescribed burns in the coming decades. These findings have important consequences for the ability to manage bushfire risk using prescribed burning in the future. The timing and resourcing of prescribed burning may be affected, with a narrower window of suitable weather conditions for burning. Alternative methods to build resilience to bushfire risk may need to be considered.