09 Dec 2010, 8:19 AM UTC
Expert urges better planning for heatwaves
Image: ABC News. Source: ABC
With heavy rains causing chaos across much of south-east Australia, last year's heatwave almost seems a distant memory. But a new report says the heatwave of early 2009 was responsible for more than 400 deaths in Melbourne and Adelaide. The author of the report is warning governments, city planners and health authorities to be better prepared for sweltering summer temperatures. Jim Reeves from the Queensland University of Technology's Institute for Sustainable Resources says the extreme conditions caused significant disruptions, distress and deaths. "The paramedical services and the ambulance services were getting call-outs, locum doctors were getting call-outs to people who were suffering from heat stress," he said. "At the end of the event, both in Melbourne and Adelaide, the morgues were full - they were at capacity and overflowing. "Year on year, compared to the January before, there were 374 excess deaths in Melbourne and between 50 and 150 excess deaths in Adelaide. So that amounts to over 400 excess deaths." He says these fatalities happened in the last week of January and do not include Victorian bushfire deaths. Mr Reeves has analysed the impact the conditions had on electricity generation and supply. "The whole electricity system from the generator to the customer was really compromised and I guess the other thing in this context was the power demand was going through the roof," he said. "The other key element during that period was the Basslink supply from Tasmania to Victoria, which supplies 6 per cent of Melbourne's power - it failed in Tasmania due to heat." For those with short memories, that had a profound impact on public infrastructure. "The buckling in the rail assets that were affected by heat, but also there were power outages that affected the electric train system," he said. "That system was severely impacted by overloaded air conditioners on trains that failed and that renders the train unserviceable. "So you had this perfect loop where demand's through the roof, lots of assets that needed exchange heat with a cooler environment couldn't, and every morning for those three days the sun would rise onto an already super-heated environment in those urban areas." Karl Braganza from the Bureau of Meteorology says more and increasingly frequent heatwaves are inevitable. "What has been clear in the last 10 years, and particularly in the last five or six years, is that events that were typically occurring once every 100 years, their return periods have greatly shrunk," he said. "So in places like Adelaide and Victoria and Melbourne, we've seen some really bad heatwaves occurring every other season. "And the climate modelling that we've done and the projections due to greenhouse gas increases shows that that is typically what you would expect as the climate system warms up; that you get more severe and prolonged heatwaves more frequently occurring." Mr Reeves says the dangers are all too real and governments, essential services and the communities need to be better prepared. "I guess what we don't want is for people to get amnesia about this event. It is a very, very lethal event," he said. But he says there are also some long-term challenges facing Australian towns and cities. "The way our cities function now - very large structures, not much airflow - there's a whole lot of what are termed urban heat island effects and micro-climates that are created across the whole metropolis," he said. "So it impacts differently and those sorts of issues can actually exacerbate, actually amplify the temperature even further." Mr Reeves says it comes down to the way cities are designed. "And how we plan for our cities and what we can do to mitigate... what vegetation, how the public realm can better plan to try and reduce some of these urban heat impacts," he said.