Key findings

The frequency and intensity of extreme events are changing

  • Climate change is already having – and will continue to have for the foreseeable future – an impact on extreme events. The consequences can have very long-lasting and sometimes irreversible effects. The frequency and intensity of extreme weather–related events are changing. By definition, extreme events are uncommon, but modelling based on historical and archaeological events and climate scenarios suggests an increasing intensity and frequency of many extreme events, a potential expansion in their distribution, changes in their duration, and increasing complexity of linked impacts. Some events, such as tropical cyclones and east coast lows, are likely to become more intense but less frequent.

Extreme events affect the natural environment and compound the impact of other pressures

  • Extreme events can have positive effects on some systems and negative effects on others. However, increasing intensity may overwhelm systems, leading to a more negative overall impact and negating the positive impacts of occasional disturbance, and the stimulus for colonisation, growth and reproduction that this may provide.
  • The natural environment faces ‘legacy’ constraints – that is, species’ adaptations and assemblages are the consequence of prior exposure and adaptation, and do not necessarily equip them for future pressures. Exposure of the natural environment to extreme events is increased by changes in the distribution of climate-related events, such as cyclones potentially tracking further south.
  • Human modification of landscapes through habitat fragmentation, changed management practices, introduction of invasive species and other pressures exacerbates the impacts of extreme events and inhibits post-event recovery.

Extreme events affect our communities and wellbeing

  • Extreme events affect the built environment. The increased frequency and intensity of extreme events will exacerbate their potential impacts on buildings and infrastructure, and the effectiveness of current engineering solutions. Changes in the distribution of events means that existing policies and regulations that are regionally based may need to be revised. Codes used during construction will need to encompass events likely to occur in the lifetime of the structure, and such codes will also need to be applied to maintenance and upgrade activities.
  • Extreme events are continuing the incremental destruction of Indigenous places and cultural values. Many sites are unidentified or undocumented as a result of population displacement, lack of access to Country, and impacts on traditional knowledge and practice. Environmental changes wrought by extreme events are also affecting the abundance and distribution of native plants and animals of cultural significance, further threatening the persistence and application of cultural knowledge and people’s cultural connections to Country.

Management and adaptation – along with significant investment and better coordination – will be needed to increase resilience

  • Climate change and its impacts, in terms of changes in the frequency, intensity and distribution of extreme events, are key pressures on the persistence of Australian environments as we know them, with knock-on effects on society. Australia has acknowledged this and is starting to take steps to address climate change. A secondary pressure results from increasing exposure of assets to the impacts of extreme events. This results from both changes in the distribution of extreme events and increasing density of population and infrastructure in areas likely to be affected.
  • Management efforts are largely in response to extreme events, but there is emerging recognition that enhancing resilience requires long-term planning and investment. This is being addressed through increasing investment and research to prioritise and support work on impact prevention, preparedness, response and recovery.
  • There is growing recognition of the role Indigenous people can play in dealing with extreme events and mitigating impacts on their communities, including cultural and environmental values. Significant areas of land are returning to Indigenous ownership or joint management through land rights and native title. A large part of this area is found in Indigenous Protected Areas, which total nearly 75 million hectares or more than 46% of the National Reserve System. The Indigenous population is widespread and vulnerable as a result of many factors, such as remoteness, lack of adequate housing and infrastructure, racism, and socio-economic and health disparities with non-Indigenous communities. Despite this, Indigenous communities display great resilience and have longstanding connections to their Country. They hold traditional knowledge and continue customary practices that can assist in planning, response, recovery and resilience to climate change and extreme events.
  • Climate change adaptation requires resources. The growing recognition of the fact of climate change, its increasing impact and the likely worsening of Australia’s exposure to extreme events has resulted in major investments and resilience-planning activities from all 3 levels of government, enormous community mobilisation and engagement, and innovative approaches from commerce and industry. There is an ongoing need to coordinate and look for synergies between these approaches, especially as we increasingly need to address multiple linked events rather than a series of individual events.