No rain for decades: Stand by for the ‘megadroughts’, scientists warn

http://www.independent.co.uk/environment/climate-change/no-rain-for-decades-stand-by-for-the-megadroughts-scientists-warn-9732483.html

Tom Bawden
Sunday 14 September 2014



Climate change is set to unleash a series of decades-long “megadroughts” this century, according to research to be published this week.

Experts warn the droughts could be even more severe than the prolonged water shortage currently afflicting California, where residents have resorted to stealing from fire hydrants amid mass crop failures and regular wildfires.

Megadroughts – which are generally defined as lasting 35 years or more – will become considerably more frequent as global warming increases temperatures and reduces rainfall in regions already susceptible, warns Cornell University’s Dr Toby Ault, the author of the new report.

Megadroughts are also likely to be hotter and last longer than in the past, he claimed. His peer-reviewed research – to be published in the American Meterological Society’s Journal of Climate – is the first to scientifically establish that climate change exacerbates the threat.

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Without climate change there would be a 5 to 15 per cent risk of a megadrought in the south-west of the US this century. With it, the probability jumps to between 20 per cent and 50 per cent, with the southernmost part of the country particularly at risk,” Dr Ault told The Independent.

The threat megadroughts pose is so great they could decimate the world’s economy and food supply, inflicting a humanitarian crisis, experts warned.

“Global warming will make droughts evermore severe and devastating in the future. The south-west of the US, southern Europe, much of Africa, India, Australia and much of Central and South America could all have a drought that lasts decades,” said Jonathan T Overpeck, an environmental scientist at the University of Arizona.

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“Many of the already drought-prone parts of the planet will see megadroughts during this century that are far worse than anything those regions have seen in the past several thousand years at least.”

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While the UK is unlikely to suffer its own megadrought, Dr Overpeck warned that Britain could be hit by a megadrought elsewhere, especially in regions it relies on for food, or in zones prone to conflict.