A MAN named Noah is predicting floods across the US. But Noah Diffenbaugh is no biblical prophet. He is a climate scientist at Purdue University, Indiana, and his computer model of the continental US is predicting at least a doubling of extremes of both rain and drought across the US by the end of this century.
鈥淓ssentially, that means that what are now the hottest two or three weeks of the year would last two to three months,鈥� says Diffenbaugh. Extreme episodes of rainfall are also projected to double, meaning that the risk of flooding could be much greater as well. 鈥淭hese are very substantial changes that could make life quite different for a lot of people.鈥�
Diffenbaugh鈥檚 model, which is four times as detailed as earlier ones, is the first simulation to incorporate local geographical features such as the rain shadow region along the Pacific coast, historical weather data and predictions of greenhouse gas emissions. It uses weather data from 1961 to 1985 and models of future weather from 2071 to 2095, which assume a doubling of the amount of atmospheric carbon dioxide (Proceedings of the National Academy of Sciences, DOI: 10.1073/pnas.0506042102).
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Besides increased flooding and droughts, Diffenbaugh鈥檚 model predicts extreme summers across the south-west and an end to the north-east鈥檚 winter as we know it.
