Climate change in Australia

Don't expect Tony Abott to take any notice

Floods could have catastrophic impact on Australia’s east coast, study warns

Mega-storms exacerbated by climate change would spell disaster for populated coastal communities

the Guardian,

11 October, 2013

A repeat of the worst floods charted over the past 150 years, potentially exacerbated by climate change, would have a “catastrophic impact” on coastal communities on the eastern seaboard of Australia, a new study has warned.

Bureau of Meteorology research of a 1,500km stretch of Australia’s east coast, reaching from Brisbane south to Eden, found that more than 600 people died from floods between 1860 and 2012.

In total, 253 major floods occurred in this time, caused by tropical cyclones and locally originating “east coast lows”.

Many of these large floods occurred in the late 19th and early 20th centuries. The report warns that a repeat of these events, with the intensity possibly ramped up by climate change, would spell disaster for communities on the coast.

Dr Scott Power, co-author of the report, told Guardian Australia: “If you look at the major cyclone of 1954, it caused deaths on the Gold Coast, but only 18,000 people lived there at the time. Now it’s more like 750,000.

“Weather prediction is much better now than it was then, but there’s the potential for absolutely catastrophic impacts if that were to occur again today. It’s still very sobering to look at the data to see what has happened as far back as 1860.”

Power said despite increased understanding of extreme weather impacts, the number of lives lost from major floods has remained consistent over the past 150 years, with an average of 2.5 deaths for each event.

“We are still seeing significant death tolls from these disasters,” he said. “Population density is certainly a factor in that but it did make us wonder whether people are just not taking these risks seriously enough.”

While several studies on the impact of climate change have indicated no tangible increase in cyclone frequency, scientists have pointed to a heightened chance of far more intense storms, escalating the risk of major damage and loss of life when a cyclone does occur.

“If you look globally, as a rule of thumb tropical cyclones are expected to diminish, but the likelihood is that they will be more intense than they used to be,” Power said.

“The models suggest that as more water is evaporated due to warming, there will be more rainfall, which means more rain and winds during cyclones. That is a robust prediction but we aren’t entirely confident over the exact magnitude.

“There is often confusion with people thinking that every single extreme weather event will increase with climate change. It’s more complicated than that. We know for example that extremely cold mornings, which can cause a severe problem for people, will see a large decrease.”

The findings were presented at the final day of the Greenhouse 2013 conference in Adelaide on Friday, which also saw research from the University of New South Wales that showed heatwaves have been “increasing over much of the Australian continent”.