Faster climate change fears in Australia

The heatwave projections for Australia appear to have been too conservative. This is part of a pattern -- the Intergovernmental Panel on Climate Change declares a range of possible climate impacts, and observations crowd the upper end of the range. From Elissa Lawrence in the Adelaide Advertiser (Australia): South Australians are being warned to brace for harsher and more regular heatwaves amid fears climate change may be occurring faster than forecast. Meteorologists and researchers say timeframes calculated by organisations such as the CSIRO for climate change impacts of higher temperatures, falling rainfall and rising sea levels are now conservative at best. And they warn the normal four seasons will blur as temperatures increase and summer stretches well into the autumn months.

…CSIRO principal research scientist Kevin Hennessy said the current heat wave was consistent with predictions of future extreme temperatures. "I would expect more events like this in future," he said. "We would anticipate in future more heatwaves will occur and that some of those will be more intense in terms of having much higher temperatures.

"This is symptomatic of the sorts of things we've been forecasting for quite a while. Warming will lead to longer summers and shorter winters. Summers will blur into what we thought was autumn and autumn will blur into what we thought was winter. We certainly will see a change in the seasons as we currently know them."

A CSIRO study last year predicted extreme heatwaves would become twice as common in SA by 2070, with the number of days over 35C to more than double. That would result in a greater number of heat-related deaths, a drain on electricity supplies through air conditioning and refrigeration demands, an increased risk of bushfires, buckling of railway lines and higher demand for water. The CSIRO study also found SA could suffer from up to 15 per cent less rainfall by 2070 as well as rising sea levels.

However, events such as the current heatwave could point to a fast-tracking of those forecasts, according to Edwin Jackson, policy and research director at the Climate Institute, a Sydney-based group raising awareness of global warming. "Climate change is just not something our children are going to have to worry about, it's something we are already seeing," he said.

…Senior climatologist at the Bureau of Meteorology's National Climate Centre Dr Andrew Watkins agreed climate projections could be happening more quickly. "We acknowledge the predictions we have made for Australia may well be conservative," he said. "You look at the global scale, things are running at the upper end of what we have been expecting. We can't say any single weather event is climate change . . . but the chances of events like this heatwave are increased under climate change.

"There is a higher chance of getting extreme events and this is certainly an extreme event that would fit into that pattern."

Photo of dried mud by Stefan Kuhn, Wikimedia Commons