In an address to the Royal Society in London yesterday, the Professor Stephen Hawking said: “As we stand at the brink of a second nuclear age and a period of unprecedented climate change, scientists have a special responsibility, once again, to inform the public and to advise leaders about the perils that humanity faces.”

The Cambridge cosmologist was speaking on behalf of the Bulletin of Atomic Scientists, who decided yesterday to move the hands on the ‘Doomsday Clock’ - devised in 1947 and originally only intended to include the atomic threat - to five minutes to midnight. The body now recognises that climate change is almost as big a threat to our existence as the misuse of nuclear weapons.

The gesture, while symbolic, is a terrifying indictmenton the governments of the world who persistently ignore the threat of global warming.

“We are learning how human activities are and technologies are affecting climate systems in a way that may forever change the earth,” said the professor.

“As citizens of the world we have a duty to share the knowledge.”

Professor Hawking rounded off by saying: “We have concluded the dangers posed by climate change are nearly as dire as those posed by nuclear weapons. The effect may be less dramatic in the short term than the destruction that could be wrought by nuclear explosions, but over the next three to four decades climate change could cause drastic harm.”

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