Source: Richie Southerton


CC2: Impacts of climate change




Climate change is already impacting on the ACT’s community, economy, and the natural environment. Observed changes include increases in tree mortality, soil erosion, air pollution, impacts on water quality, recreational water closures, and extended periods of reduced river flows and water resources. The ACT’s warming climate, combined with periods of below average rainfall, is increasing fire risk and was a significant factor in the severity of the 2020 bushfires.


Environmental condition is healthy across the ACT, OR pressure likely to have negligible impact on environmental condition/human health.

Environmental condition is neither positive or negative and may be variable across the ACT, OR pressure likely to have limited impact on environmental condition/human health.

Environmental condition is under significant stress, OR pressure likely to have significant impact on environmental condition/ human health.

Data is insufficient to make an assessment of status and trends.



Adequate high-quality evidence and high level of consensus.

Limited evidence or limited consensus.

Evidence and consensus too low to make an assessment.

Assessments of status, trends and data quality are not appropriate for the indicator.

The warming associated with climate change has already affected the ACT’s ecosystems and biodiversity, human health and livelihoods, and changed the intensity and frequency of heatwaves, droughts, storms, and floods.

Attributing environmental changes to climate change alone is difficult due to the range of factors that affect the environment. However, data used in this report suggest the following impacts from climate change:

There will be many other impacts which are not captured by data used in this report. This is particularly the case for subtle changes that occur over long periods. For example, it is widely accepted that climate change is having a significant impact on terrestrial and aquatic ecosystems and the biodiversity they support. The repercussions of climate change on human health and wellbeing are also well documented.[5]

It is also difficult to determine climate change impacts at the local level, particularly for the natural environment. This is because the severity of changes depends on a range of factors including landscape types, elevation, and the sensitivity and resilience of ecosystems. This means that the implications of climate change will differ across the ACT with some areas and ecosystem types more affected than others.

The severity and size of the ACT’s 2020 bushfires were a consequence of climate change which is contributing to more severe fire seasons that are starting earlier and lasting longer. There were extreme temperatures over the 2019–20 summer with 4 January recording the ACT’s hottest day on record at 44°C. The mean maximum and minimum temperatures over the summer were the third warmest on record. In addition, the ACT was experiencing the lowest rainfall deficit on record, along with much of NSW. The combination of heat and low rainfall provided optimum conditions for the bushfires, for both temperature and dry fuel loads.

Climate conditions led to concerning fire severity risk conditions for the ACT prior to the fires. The risk conditions were particularly elevated in the month leading up to the Orroral Valley fire and for the first days of the fire. Fire severity risk conditions included two catastrophic and two extreme risk days, seven severe days, ten very high and nine high risk days. Such conditions significantly increased the severity and spread of the Orroral Valley fire.

The impacts of the 2019–20 bushfire season on the ACT’s community, environment and biodiversity are discussed in 4. Bushfires in the ACT. The future risk of bushfire in the ACT is also discussed.

More comprehensive data is required on the impacts of climate change on natural ecosystems, the urban environment and human health to improve knowledge, adaptation and resilience.