Britain's rivers could run dry

Guardian (UK): Britain's rivers could nearly run dry because long hot summers caused by climate change will not be sufficiently compensated by wetter winters, researchers predict. It is a scenario that would endanger wildlife and send household water bills soaring. Flows in the Mersey and Severn are likely to be reduced in summer by up to 80 per cent by 2050, according to a study by the Environment Agency. The Thames's flow is likely to decline by up to 50 per cent during the same period.

It had been hoped that, as global warming leads to more extreme seasons, summer droughts would be offset by an increase in winter rainfall. However, while wetter winters are expected, they will not be damp enough to make up for the lack of rain during the hotter summers.

… Ian Barker, head of water resources at the Environment Agency, said yesterday: 'For a long time, we've known climate change would result in wetter winters, which would increase winter flows in rivers, and that it would also result in drier summers. 'The received wisdom was that the two would balance each other out and overall we'd end up with the same amount of water, just distributed differently throughout the year.

'But we wanted to understand how much extra rainfall we might get in winter, and how much less rainfall we might get in summer. The net effect is that overall, although winter rainfall might increase by 10 per cent, the period of higher river flows is reduced, so it's perhaps only December, January, February, maybe into March. The period when you'd see lower river flows because the rainfall is significantly less would extend from April right through to November in some parts of the country.' Barker warned: 'Overall, it means that, by the 2050s, there's a net reduction in the amount of water resources available for water companies to pump out of rivers, farmers to use for irrigation and also to support wildlife in rivers….

A view from a northbound Severn Valley Railway service as GWR Manor Class 4-6-0 locomotive 7802 Bradley Manor hauls its train over the river that gives the railway its name. Shot by Chris McKenna (en:User:Thryduulf), Wikimedia Commons, nder the Creative Commons Attribution ShareAlike license versions 2.5, 2.0, and 1.0