FED: Pollution over Europe could be reducing rain in Australia

AAP General News (Australia)
08-26-2009
FED: Pollution over Europe could be reducing rain in Australia

CANBERRA, Aug 26 AAP - Atmospheric aerosol pollution over Europe, North America and
Asia could be responsible for global rainfall variations in Australia, new research suggests.

Dr Leon Rotstayn from the Centre for Australian Weather and Climate said it appeared
pollution aerosols over Asia could be responsible for higher rain in Australia's north-west,
but less on the east coast.

Higher aerosol levels in the northern hemisphere seemed to affect sea level air pressure
and in turn rainfall.

"Increasing sea level pressure at 40 degrees south suggests decreased rainfall in parts
of southern Australia," he told an online briefing. He said this needed further research.

Dr Rotstayn said aerosols partly masked global warming although the effect was variable.

He said the climatic importance of aerosols had been under-recognised in Australia
because pollution levels here are low.

One issue is that the presence of greenhouse gases extends over the longterm, while
aerosols remain in the atmosphere for as little as a week.

"It is important that we do understand the relative roles of these different mechanisms
in driving rainfall changes," he said.

Dr Rotstayn said while some types of aerosols had a negative global warming effect,
others such as carbon soot had a warming effect on climate and had been implicated in
melting of glaciers.

Professor Andi Andreae, director of the Max Planck Institute for Chemistry in Germany,
said removal of atmospheric aerosols could produce immediate warming of perhaps half a
degree.

"Emissions of a lot of the aerosols are coupled to emissions of the greenhouse gases,"

he told the briefing.

"One of the largest emitters of aerosol particles is in fact our power plants, especially
coal-fired power plants."

AAP mb/sb/maur

KEYWORD: CLIMATE AEROSOLS

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