Building evidence that effective heat alert systems save lives in southeast Australia

Neville Nicholls, Margaret Elizabeth Loughnan, Nigel James Tapper

Research output: Other contributionOther


Record heat waves in southeast Australia in January 2009 and January 2014 led to an increase in mortality and morbidity, in excess of the rates expected for the time of the year. Both heat waves recorded daily maximum temperatures well in excess of 40°C over three- and four-day periods respectively, and minimum temperatures above 25°C, with both heat waves concluding on Fridays.

In the January 2009 heatwave, a prototype heatwave alert system had just been introduced, based on research identifying a threshold temperature above which excess mortality occurred in Melbourne, Australia. By the time of the January 2014 heat wave, the heat alert system had been considerably refined, based on further scientific work and intense interactions between climate scientists and public health authorities. The excess mortality associated with the 2014 heat wave was substantially lower than in 2009, even though the 2014 heat wave lasted longer.

The mortality associated with the two heat waves is illustrated in Figure 7.1, which shows the number of obituaries published in a major Melbourne newspaper on the Monday–Wednesday after the two heat waves. In the days after the 2009 heatwave deaths increased by 60% (blue line), relative to the weeks before and after the heat wave (the numbers of obituaries for these weeks are shown by black broken lines). After the 2014 heat wave, deaths increased by 25% (orange line), relative to the mortality in the weeks before and after (shown by the black full lines). The only substantial difference between the two heat wave events was the better-developed and implemented heat wave alert system in 2014. This suggests that the heat wave alert in 2014 saved many lives.
Original languageEnglish
TypeCase study in a report chapter
PublisherWorld Meteorological Organization
Number of pages2
Place of PublicationGeneva Switzerland
Publication statusPublished - 2016

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