Highlights
Tropical Cyclone Yasi has been, according to Queensland Premier Anna Bligh, the “most severe, most catastrophic storm that has ever hit our coast”.
I asked Dr Andrew Ash, who is director of the CSIRO’s Climate Adaptation Flagship, if perhaps it didn’t just used to be really wet and windy before the drought and maybe we’d just forgotten about it and now it seemed worse because we’ve lost our gumboots and umbrellas. He said we hadn’t forgotten. He said it really was very windy and wet right now.
“We have had stronger cyclones in history and we have had cyclones just as large in size, but it is rare to get both a very large and intense cyclone,” he explained.
“The flooding we have experienced to date on the whole has been within the bounds of historical events though in some areas, such as the Western Downs in Queensland and parts of Victoria, all time records have been broken.
“While extreme events like flooding and cyclones are an expected feature of La Nina events, the oceans around eastern and northern Australia are particularly warm at present. It is usual for the ocean in the Western Pacific to be warm during a La Nina event but the ocean temperatures are currently the highest on record.”
It’s data which is backed up by the Bureau of Meteorology too. In December 2010 the Southern Oscillation Index, a measure of the extent of La Nina, recorded a level of 27.1. It sounds boring, but 27.1 is a big deal. Twenty-seven point one is the highest recorded December value in history.
Exactly why ocean temperatures are currently the highest on record is the $3 billion question – that’s the amount of money the Government thinks it will save each year by figuring out ways to acclimatise to climate change. The answer, according to Dr Ash, the man in charge of finding a solution, is:
“The record warm temperatures are most likely a combination of La Nina and additional warming from human activities.”
The fact that the two biggest natural disasters on record to hit Queensland have occurred within three weeks of each other is not a coincidence. It is a direct result of the Pacific Ocean being warmer than we’ve ever known it to be.
“While the flooding events and cyclones experienced this year aren’t caused by climate change, the record warm ocean temperatures provide conditions more conducive to exacerbating these naturally occurring events associated with La Nina,” Dr Ash explained.
The source article Coincidence or climate change? was published February 3, 2011 by Australian Broadcasting Corporation .
