How does France differ from North Dakota?

Fracking has caused an increase in the supply of US shale oil that will change the US from the world's leading importer of oil to a net exporter.

"North America has set off a supply shock that is sending ripples throughout the world," said IEA executive director Maria van der Hoeven.

The surge in US production will reshape the whole industry, according to the IEA, which made the prediction in its closely-watched bi-annual report examining trends in oil supply and demand over the next five years.

The IEA said it expected the US to overtake Russia as the world's biggest gas producer by 2015 and to become "all but self-sufficient" in its energy needs by about 2035.

Interestingly,  the process has been banned in France, while the UK recently lifted a moratorium on drilling for shale gas.