Two recent climatic events are warning signs that climate change may be proceeding much more quickly than previously thought, James Lovelock claimed.
They are the increasingly rapid melting of the Arctic ice-sheet covering Greenland, which will raise global sea levels considerably, and the extreme heatwave in western central Europe in the first two weeks of last August.
The latter, which saw the British temperature record exceed 100F for the first time, produced 20,000 deaths of mostly elderly people in France, where heat levels, especially at night, were highest.
Senior scientists, including a team from the Swiss Met Office and Phil Jones, head of the Climatic Research Unit at the University of East Anglia, have since said that last year's heatwave was entirely unprecedented in climatic history, and attributed it directly to climate change. "There's no question in any reasonable scientist's mind that that was the first real bad event of global warming," said Professor Lovelock. "But the media picked it up only as a story about the wickedness of the French in not looking after their old people."
Just as alarming, he said, is the dissolving of the Greenland ice sheet, which measurements show is "melting far faster than we expected".
Describing the picture on the front page of today's Independent, he said: "That's a kilometre up in Arctic Greenland, near the North Pole, and that's what it looks like in summer now. There are torrents of meltwater plunging off the glaciers."
The 2001 report of the UN's Intergovernmental Panel on Climate Change foresaw a global temperature rise of up to 5.8C during the next century. But Professor Lovelock believes things will happen much faster than on a 100-year time scale.
He said: "I think in the past we thought more in terms of, it would get hotter, things would change, you might be able to grow Mediterranean plants in Britain and things like that, it didn't seem at all too bad; you knew there'd be some places that wouldn't be fine, but others would be nicer than they were.
"Now there's a growing awareness that global warming is far more serious than we ever realised, that it is proceeding more quickly, and that it poses a threat to future generations and even to civilisation itself."