Powder keg: Australia primed to burn

Australia has long been referred to as a land of “drought and flooding rains”, prone to bushfires as well as intense rainfall events. Periods of hot, dry, windy weather have regularly dried out vegetation and made it susceptible to ignition, alternating with prolonged wet periods that have promoted rapid and widespread vegetation growth. 

Climate change, driven by the burning of coal, oil, and gas, is worsening these extreme weather events (IPCC 2021a). The Black Summer bushfires in 2019-2020, as well as the record-breaking Great Deluge of 2022— both of which claimed lives, livelihoods, property and crops—were exacerbated by climate change (see, for example, Binskin et al. 2020; Climate Council 2022).

For the past three years, Australia has experienced wetter than average conditions, with record-breaking rainfall and floods across New South Wales (NSW), Queensland, Victoria, South Australia and Tasmania (BoM 2022). This has been due to a rare ‘protracted’ La Niña event together with a negative phase of the Indian Ocean Dipole and a positive phase of the Southern Annular Mode. 

Given the years of rainfall since Black Summer, it is reasonable to expect that fire risk may have slipped from the Australian public’s consciousness. However, very wet periods often make fire services nervous, because they are a double-edged sword. On one hand, rain keeps vegetation wet, reducing the likelihood of ignition and limiting fire spread during the wet period. On the other hand, it leads to prolific growth, even in ‘desert’ areas that typically have insufficient vegetation to pose any fire risk.

The wet weather also limits the ability of land managers and fire services to carry out fire prevention and mitigation works, for example, hazard reduction burning cannot be carried out during wet conditions. When wet weather inevitably gives way to hot, dry conditions, light grasses and shrubs die and dry out and we are then left with more vegetation available to burn.