Intensifying Climatic Effects of the Indian Ocean Dipole Exaggerates Australia Bushfires Risk

Southeastern Australia (SEA) is no stranger to bushfires, but the 2019–2020 season was unprecedented in both size and intensity, accompanied with record-breaking high temperature and rainfall deficit. Future projections warn that Australia's fire season will face more frequent droughts and heat waves if emissions are not significantly reduced. Although studies have indicated 2019 extreme positive Indian Ocean Dipole’s (pIOD) important contribution to this mega bushfire, our research study highlights IOD's climatic effect on SEA varied and intensified in recent decades. Due to anthropogenic climate change, the likelihood of pIOD-induced severe bushfires danger has risen by 16%–32%. Coupled Model Intercomparison Project Phase 6 projections reveal that SEA will inevitably face an increasing crisis with bushfire in a warmer future. Under the plausible high-emission scenario SSP370, pIOD-induced mega bushfires comparable to the 2019–2020 event increase at nearly 1.8 times the rate of medium-emission SSP245, whereas the upper-bound SSP585 scenario projects over twice SSP245's increase.