Climate change has led to longer, more intense fire seasons and an increase in the average number of elevated fire weather days, as measured by the Forest Fire Danger Index (FFDI). Last year saw the highest annual accumulated FFDI on record. Australia was the first country in the world to report the impact of climate change on bushfires through CSIRO’s work to model the increase in high fire danger days.
During Senate Estimates last week, CSIRO was asked specifically about the Climate Change in Australia (2015) report and if it has undertaken any explicit studies to attribute the Australian increase in fire weather to climate change since that report. CSIRO confirmed it has not.
This should not have been interpreted as there being no link between bushfires and climate change
Research about the detection of climate change and attribution to an increase in conditions which influence (not cause) bushfires has been published since the 2015 report. CSIRO draws on this data and observations.
Specifically in 2018, the Australian Government’s National Environmental Science Program published "Bushfires and climate change in Australia [pdf · 3.5mb]" showed a clear trend towards more dangerous conditions during spring and summer in southern Australia, including increased frequency and magnitude of extremes, as well as indicating an earlier start to the fire season, with these changes attributable at least in part to anthropogenic climate change including in relation to increasing temperatures (Dowdy 2018). Additionally, a recent study examining an extreme fire event in Queensland during 2018 found that climate change made the conditions more dangerous (Lewis 2019). See references below.
- Dowdy, A.J., 2018. Climatological variability of fire weather in Australia. Journal of applied meteorology and climatology 57(2), pp.221-234, https://doi.org/10.1175/JAMC-D-17-0167.1.
- Lewis, S.C., Blake, S.A., Trewin, B., Black, M.T., Dowdy, A.J., Perkins-Kirkpatrick, S.E., King, A.D. and Sharples, J.J., 2019. Deconstructing factors contributing to the 2018 fire weather in Queensland, Australia. Bulletin of the American Meteorological Society, (2019).