The sensitivity of Australian fire danger to climate change

Global climate change, such as that due to the proposed enhanced greenhouse effect, is likely to have a significant effect on biosphere-atmosphere int eractions, including bushfire regimes. This study quantifies the possible i mpact of climate change on fire regimes by estimating changes in fire weath er and the McArthur Forest Fire Danger Index (FDI), an index that is used t hroughout Australia to estimate fire danger. The CSIRO 9-level general circ ulation model (CSIRO9 GCM) is used to simulate daily and seasonal fire dang er for the present Australian climate and for a doubled-CO2 climate. The im pact assessment includes validation of the GCMs daily control simulation an d the derivation of 'correction factors' which improve the accuracy of the fire danger simulation. In summary, the general impact of doubled-CO2 is to increase fire danger at all sites by increasing the number of days of very high and extreme fire danger. Seasonal fire danger responds most to the la rge CO2-induced changes in maximum temperature.