Long-Term Outlook For Western Australia Drier Than First Projected

Global warming could make WA even drier than experts had predicted, according to new climate research. The findings raise the prospect of worsening summer water shortages as subtropical regions become more parched. Computer models have already forecast that global warming will make dry areas even drier, while increasing severe rainfall and flooding in already wet areas such as Australia’s tropical far north.

But the new research, based on satellite rainfall data over the past 21 years, suggest that this polarising trend is even more pronounced than models had foreseen. That is ominous news for southern WA, which has already seen rainfall declines of 20 per cent since the 1980s. In contrast, wet tropical areas are likely to suffer an increase in heavy rainfall, raising the prospect of flooding, according to Richard Allan, of Reading University, in Britain, who led the study.

Global warming is thought to boost tropical rainfall because warmer seas make for faster evaporation and more extreme rainfall. Dry, subtropical areas in turn become drier because more of the world’s total rainfall is clustered in tropical storms. “It can almost ‘rob’ the drier regions of their rainfall,” Dr Allan said.

Last year, the International Panel on Climate Change, a United Nations group of 2000 climate experts, predicted that by the end of the century, average monthly rainfall in WA would have decreased as much as 3mm.

EDIT

http://www.thewest.com.au/default.aspx?MenuID=146&ContentID=90107

:shrug: