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Greener but Drier

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Satellite observations published in Nature Climate Change have revealed that plants in Australia’s semi-arid and subtropical regions are becoming greener because of increased atmospheric carbon dioxide. However, the vigorous growth of plants requires more water, so less run-off now flows into many of Australia’s river basins.

“To compound matters, many important regions are projected to experience future declines in rainfall as a result of climate change,” said lead author Dr Anna Ukkola, who performed the research at Macquarie University but is now based at the ARC Centre of Excellence for Climate System Science.

“This means water resources for agriculture and environmental flows in places like the Murray-Darling Basin, inland Queensland and south-western Western Australia’s wheatbelt will be reduced even further.”

But there was also a positive side to the greening. Because plants use water more efficiently where there is more carbon dioxide, less water is required to produce the exact same amount of leafy vegetation under high CO2 conditions.

The satellite measurements indicated that areas of Australia with sufficient water resources were indeed showing an increase in vegetation. “This increased production is a boon for farmers where water resources are readily available, but the problem is for those regions that already experience water...

The full text of this article can be purchased from Informit.