Friday, March 4, 2011

Climate change 'will bring drought, not rain, to East Africa'

Dann Okoth in SciDev.net: East African environmental specialists have questioned new research that concludes that that climate change will bring increased drought, rather than more rain, to the region. The new research, published in Climate Dynamics, predicts that the droughts common in eastern Africa over the past 20 years are likely to continue if global temperatures rise further.

But the prediction contradicts the scenario of increased rainfall projected by the Intergovernmental Panel on Climate Change (IPCC). The researchers, from the University of California, Santa Barbara, studied temperature, wind speed and precipitation data over the last 20–30 years to determine what was driving climate variations in the tropical Indian and Pacific Ocean regions.

They found that the Indian Ocean has warmed particularly fast, increasing rainfall over the ocean and the westward movement of dry air over Eastern Africa — hence decreasing rainfall. The severe food shortages experienced by millions of people in Ethiopia, Kenya and Somalia will be exacerbated by increased drought in the future, said the researchers.

…But the conclusions were dismissed by some East African climate researchers. Richard Odingo of the University of Nairobi and former vice chair of the IPCC said the research was "half-baked" and served only US relief interests in the region. He said it was erroneous to say the IPCC was wrong as the organisation used data going back 300 years from many different sources, as well as taking into account links between weather systems high in the Earth's atmosphere.

…But Park Williams, co-author of the paper and a postdoctoral fellow at the University of California, Santa Barbara, said global models [such as those produced by the IPCC] have a notoriously difficult time accurately simulating rainfall patterns over tropical land masses. "Global models are tending to forecast a global trend toward a more El NiƱo-like climate which would, for example, generally mean more rainfall for Ethiopia and Kenya during the March to June period…

The desert east of Sudan, shot by Sharif Baasher, Wikimedia Commons via World 66, under the Creative Commons Attribution-Share Alike 1.0 Generic license

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