Future changes to meteorological drought in Australia: insights from the Australian Climate Service’s drought and changes in aridity team

In Australia, drought has dramatic consequences for social, economic and environmental systems, making it critical to understand how this hazard may change in the future. The Australian Climate Service (ACS) is a national interagency collaboration to service Australia’s climate needs. In this paper, we unpack insights from the ACS’s drought and changes in aridity team derived using dynamically downscaled and bias-adjusted CMIP6 (sixth Coupled Model Intercomparison Project) projections for two emissions scenarios. By applying a global warming level framework, we report on both mean state shifts to meteorological drought, as well as outlier ensemble members useful for high-impact, low-probability event planning. Key findings indicate high-confidence increases to time spent in drought across southern and south-western parts of Australia, with some areas projected to experience meteorological droughts up to 30% longer and 75% more frequently compared to the current climate. In regions of lower confidence change, such as the tropics and parts of the Murray–Darling Basin, a range of diverging drought futures are unpacked. The findings of this analysis can enable decision makers to make informed choices in regions of higher confidence change, and to develop adaptive strategies where there may be more uncertainty. As climate change intensifies, such planning will be critical to sustaining the long-term resilience and vitality of drought-prone ecosystems and communities.