Russia's richest man Alisher Usmanov reveals that he bought US scientist James Watson's Nobel Prize gold medal in order to return it to him.

Poor families in the UK will need more help to pay for heating their homes as energy bills rise, government advisors have warned.

Catholic bishops from around the world are calling for an end to fossil fuel use and increased efforts to secure a global climate treaty.

Activists apologise for any "moral offence" it has caused, after a publicity stunt on the ancient Nazca lines in Peru.

Data from Europe's Rosetta probe suggests that water on Earth may not have come from comets, scientists conclude.