Sir Richard Branson recently fortified his role as Mr. Environment? by teaming up with Al Gore to announce a multi-million pound prize for the best method of removing thousands of tonnes of carbon dioxide from the atmosphere.

The prize - approximately £12.5 million - will go to the inventor who creates the best system capable of absorbing and storing one billion tonnes a year of the most common greenhouse gas, carbon dioxide. To oversee the project, Sir Richard has convened a panel of judges consisting of physicists, NASA engineers, and zoologists.

Branson has already pledged to invest £1.6bn in profits from his travel firms, including Virgin Atlantic and Virgin Trains, towards research into renewable energy technologies.

Other scientists are also looking at schemes that might "scrub" the air of CO2, collecting the gas for safe storage; but many critics say the energy required to achieve this would make such an approach self-defeating.