Wednesday, February 4, 2009

Category 5 cyclones and Australia

NT News (Australia): Dr Greg Holland, from America's National Center for Atmospheric Research, says there has been between a 300 and 400 per cent increase in category 5 storms in the past 10 years in the US. He said the Top End seemed to be experiencing a similar trend, although records were less reliable due to changes in observing and analysis practices

"I think that what we're seeing here in the north Australia region - with the Monicas and storms like that - is a similar sort of thing," he said. "It's not good news ... a category 5 storm typically causes more than 1000 times the damage of a category 1 storm."

Dr Holland - an Australian who was a forecaster in Darwin during Cyclone Tracy - gave a talk in Darwin this week about his analysis of cyclone data. He believes the increasing number of severe cyclones is an indicator of climate change. He said slight increases in the overall total of cyclones might be difficult to detect, but when there were changes in rare events, it was by a "very large" proportional amount.

"So that climate (change) signal will appear first in the extreme events, be it tropical cyclones, heat waves or heavy rain," he said. Dr Holland said although Australia had the world's best building codes - thanks to Tracy - it was time the Top End reviewed its codes…..

Buildings in Darwin, Australia, after Cyclone Tracy, 1970, shot by Billbeee, under the terms of the GNU Free Documentation License, Version 1.2

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