Climate change and bushfire

Climate change and bushfire risk

Climate change is influencing the frequency and severity of dangerous bushfire conditions in Australia and other regions of the world, including through influencing temperature, environmental moisture, weather patterns and fuel conditions. There have been significant changes observed in recent decades towards more dangerous bushfire weather conditions for various regions of Australia.

In particular, observed changes in southern and eastern Australia include more extreme conditions during summer, as well as an earlier start to the bushfire season with dangerous weather conditions occurring significantly earlier in spring than they used to. These trends towards more dangerous bushfire conditions are at least partly attributable to human-caused climate change, including through increased temperatures. Northern Australia, which sees significant fire activity during the dry season, has experienced increases in monsoonal rainfall that have increased fuel growth in recent decades, as a key factor influencing fire danger in that region.

In relation to fire ignition, there is some indication that climate change could influence the risk of ignitions from dry-lightning (i.e., lightning that occurs without significant rainfall) while noting relatively large uncertainties in currently available model representations of this phenomenon. Additionally, there has recently been a number of devastating fire events in Australia associated with extreme pyroconvection (including thunderstorm development in a fire plume), with recent research indicating a long-term trend towards increased risk factors associated with pyroconvection in southeast Australia. Bushfire weather conditions in future years are projected to increase in severity for many regions of Australasia, including due to more extreme heat events, with the rate and magnitude of change increasing with greenhouse gas concentrations (and emissions).

Learn more about fire weather at the Bureau of Meteorology’s Fire Weather Knowledge Centre webpage.

(Source: Bureau of Meteorology)

Changes to fire weather in Queensland

The ‘Changes to Fire Weather in Queensland’ report describes long-term changes in fire-weather conditions for Queensland. The report was prepared by the Bureau of Meteorology for Queensland Fire and Emergency Services (QFES).

Six key findings in the report’s executive summary include:

• Annually averaged maximum temperatures have risen for most of the State.
• Annual rainfall has risen over most of the far west and far north of the State, but has declined across the remainder of the state particularly on the east coast.
• Annual accumulated Forest Fire Danger Index (FFDI), highest daily FFDI and incidence of days greater than or equal to FFDI 25 has risen across most of the state, particularly in the South.
• Days greater than or equal to FFDI 25 are occurring earlier in Spring and in the case of the South West on occasion in late Winter. Thus, fire seasons are starting earlier and in some cases finishing later.
• Fire weather changes have been more rapid in recent decades.
• An associated study examining FFDI trends using climate change projections indicate that the trends observed are likely to continue.

The ‘Changes to Fire Weather in Queensland' report (PDF|7.8MB) is published on the QFES website.

(Source: QFES)