Mark Carpenter, research fellow at Cranfield University's Chemical Safety, Fuels and Environment Group, said that hydrocarbon fuels were "a very good way of storing energy" but that linking the process to renewable energy was the only way to make it tenable.

BBC: Petrol from air: Will it make a difference?

He said the company had agreed to amend its proposals to use only "environmentally friendly" fuels approved by the Environment Agency and policed by the Port Authority.

BBC: Artist's impression of the proposed plant

Rampant population growth and changes to the environment caused by humans, including the burning of fossil fuels and the conversion of nearly 43% of the planet's land to farms or cities, threaten to cause an abrupt and unpredictable shift in the global ecosystem, 22 scientists from five countries said in their paper.

CNN: STORY HIGHLIGHTS

Most of this is doing little good for the environment, and stopping subsidies for such fuels would boost the supply of grain for feeding people on a scale similar to the hit that the past three decades of warming have provided.

ECONOMIST: Climate change and crops