But critics of shale gas point to environmental concerns such as high water use and possible water contamination, the release of methane and, to a lesser extent, earth tremors caused by drilling.

BBC: US oil production 'to jump by a quarter by 2014'

But they do not have to use coolant fluids like water that must operate at high pressures in order to achieve high temperatures.

FORBES: Explainer: What Caused The Incident At Fukushima-Daiichi

Even coastal defences built to withstand the strongest tropical storms may be little use when struck by a wall of water up to 10m high, as hit some Asian countries on Sunday.

ECONOMIST: Deluged without warning | The

The goal was to convene a meeting of high level experts in transboundary cooperation, biodiversity conservation and sustainable use of land and water resources.

UNESCO: Transboundary cooperation for conservation and sustainable use of terrestrial and water ecosystems | United Nations Educational, Scientific and Cultural Organization