World getting wetter and warmer

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World getting wetter and warmer
May 9, 2004 - 2:05PM
http://www.theage.com.au/articles/2004/05/09/1084041260699.html


Despite the seemingly never-ending drought in Australia, the world is getting wetter and warmer.
That was the conclusion of almost 100 greenhouse research scientists from across Australia at the annual science meeting of the cooperative research centre for Greenhouse Accounting.

They found the global water cycle had changed in response to greenhouse emissions - more rain was falling and there was less evaporation.

"Rainfall, on average, is increasing (though decreasing in some regions in Australia and elsewhere)," the scientists said in their communique.

"Contrary to widespread expectations, potential evaporation from the soil and land-based water bodies like lakes is decreasing in most places."

Less evaporation is a result of the world being cloudier than it used to be.

"Clouds disperse sunlight, so less radiation from the sun is reaching the earth's surface directly," the communique said.

"As the world warms it is, on average, getting wetter."

The lower evaporation levels could signal a change in habitats, ecosystems and biodiversity with the conditions favouring long-lived woody plants like trees over shorter lived plants.

The scientists found that across the world trees and shrubs were increasing in what had previously been grassland areas.

They said changes in the quality of light reaching the earth's surface from the sun, also a result of climate change, may affect plant growth, with increased cloudiness allowing plants to photosynthesise more effectively.

While rising levels of carbon dioxide in the atmosphere generally leads to faster growth in plants, recent research found plants in Australia have not benefited or have fared worse as carbon dioxide levels rise.

The scientists said research showed Australia would benefit from using forests, grasslands and farms to absorb more greenhouse gases from the atmosphere.

"Forests, farms and grasslands across the world absorb significant volumes of greenhouse gases," they said.

"They have the potential to absorb more, ameliorating climate change.

© 2004 AAP