This is the first state of the environment report to have a dedicated theme relating to extreme events – a response to the increasing scale, frequency and impact of climatically driven events over the past 5 years. In many cases, these events been disastrous for individuals, communities, industries and the environment.

Our aim has been to bring together an overview of the hundreds of reports, reviews and research papers written about these topics in recent years, and to provide an entry into the vast scholarly literature and community-informed reporting that have developed. In part, this has meant identifying a small number of representative case studies that exemplify the sorts of impacts that we see, hear about or measure. Some of these are reported here; others are featured in the other domain-specific themes.

We have also tried to strike a balance between identifying the consequences of extreme weather events for natural systems and for permanently settled, industrialised Australia – its communities, industries and infrastructure. In natural systems, extreme events may cause disturbance but also stimulate rapid response to that disturbance. In some cases, they are essential – if irregular and unpredictable – drivers of environmental change. Natural events only become disasters when people and their property are impacted, and this occurs frequently in post-colonial Australia.

However, climate change is producing weather events and climates beyond our measured records, and seemingly outside the range of events that many of our environments and species have become adapted to. Changes in the frequency, intensity and distribution of events, compounded by habitat fragmentation, introduced species, hard infrastructure and environmental modification, are threatening the resilience of some of our natural communities. Consequently, in our assessments, we have frequently identified the trend as ‘deteriorating’, although with low or limited confidence because our understanding of long-term trends in the spatial and temporal distribution of rare events is poor, and our forecasts are based on modelled scenarios.