Dry argument here to stay

June 05, 2008, Melbourne -CLIMATE change is stamping its presence across Victoria. As we leave behind another dry autumn, we are grappling with the reality that our average rainfall is less than it was.Governments, quite rightly, are becoming more concerned. They want to know how strong the signals of climate change are.

Well, across my desk, and those of other scientists engaged in climate, water and natural resource research around the country, the evidence just keeps rolling in.

What most people fail to realise is that the evidence largely appears in international science journals, and only after passing a jury of peers before which all scientists must submit their work for scrutiny.

In the latest studies published in recent weeks, Melbourne scientists Wenju Cai and Tim Cowan have produced evidence suggesting real links between global warming and changes in Victoria's rainfall.

In the first study, their analysis showed that global warming has been changing sea-surface temperatures to the north of Australia and atmospheric circulation patterns over the sub-tropical Indian Ocean.

These changes, according to Cai and Cowan, are the source of a 40 per cent downturn in autumn rainfall since 1950; the month of May showed the biggest downturn.

In the second study, the scientists presented compelling evidence of why we must be aware of consistently increasing temperatures associated with global warming.

Since 1950 the annual average temperature in the southern Murray Darling Basin has risen by 0.9C.

That may not seem like much, but this temperature increase has been accompanied by higher evaporation and, according to modelling by the Murray-Darling Basin Commission, 15 per cent less runoff flowing into the river system.

Victoria isn't alone. During the past 50 years there has been a decreasing trend in rainfall over much of Australia, although it varies from season to season and region to region.

The community's awareness of climate change in Australia has increased dramatically in recent years, perhaps largely due to the need to manage with less water.

We should stop thinking about "drought" and perhaps start thinking about the new climate. It will rain again, but the prospect is that we will need to manage with less.

Victoria leads the way in its quest for more understanding of how climate change will affect society.

The evidence grows that living with climate change is a fact of life.

We had better adapt to it.

Dr Chris Mitchell is the foundation director of the Centre for Australian Weather and Climate Research: a partnership between CSIRO and the Bureau of Meteorology

Original Source: Herald Sun Melbourne