The depths of the loneliest, wildest ocean on earth could hold the answer to saving the planet from the effects of greenhouse gases, boffins reveal.

A team from the National Oceanography Centre in Southampton have discovered that plankton fed with iron will absorb carbon dioxide taking it so deep in the Southern Ocean that would be out of circulation for a century.

But environmentalists say the ‘iron fertilisation’ programme could upset the eco-system with unknown results.