Heatwaves in Australia 1788-2010: who, really, is most at risk?

Lucinda Coates
Risk Frontiers, Macquarie University, Sydney, NSW, Australia

Effective planning for natural hazards includes knowing who is most at risk. Heatwaves, due to their complex and pervasive nature, have not traditionally attracted the study due their importance in terms of human mortality. Research utilising PerilAUS - Risk Frontiers' database of historic natural hazard impacts - has quantified heat-associated deaths in Australia from European settlement to the present day. Demographic trends and circumstances surrounding such deaths were analysed in order to understand which groups of the population have been most vulnerable and how these trends have changed over time. To date, figures indicate that, from 1844-2010, heatwaves have been responsible for at least 5 332 fatalities. Data from 1900 onwards indicate they have killed more Australians than the combined total of deaths from all other natural hazards and that approximately 31% of these deaths have occurred in just nine events. Trends examined to date suggest that the overall decadal death rate has fluctuated over time but has steadily declined from a high of 1.69 deaths per 100 000 population in the 1910s to its current rate of 0.26. The male to female death-rate ratio has fluctuated over time from 4.81 in the 1880s to the current 1.10 and approaches, but does not reach, equality. Case studies were undertaken of five of the worst heatwave events in Australian history - 1896, 1908, 1939, 1959 and 2009 - to further explore any trends. Policy implications in view of changing climate and societal conditions are discussed with respect to the trends analysis.