Five years ago, he had claimed: 'Before this century is over billions of us will die and the few breeding pairs of people that survive will be in the Arctic where the climate remains tolerable.'
But in an interview with msnbc.com he admitted: 'I made a mistake.'
'The problem is we don’t know what the climate is doing,' he said. 'We thought we knew 20 years ago. That led to some alarmist books – mine included – because it looked clear cut, but it hasn’t happened.
'The climate is doing its usual tricks. There’s nothing much really happening yet. We were supposed to be halfway toward a frying world.
'[The temperature] has stayed almost constant, whereas it should have been rising - carbon dioxide is rising, no question about that.'
What's annoying is that those who were sceptical about such claims were treated like lepers. The science was in, they were told. There was a scientific consensus. Only the ignorant or those with a vested interest could possibly have doubts, it was said.
And now we have an admission that the science is fallible. What was predicted to happen isn't happening.
That doesn't mean that the goal of developing clean sources of energy is a bad one. But it shows that we need calm, clear and courageous minds to stand up to unreasonable claims, even if those claims are made under the mantle of science.
Think of what was being suggested in reaction to the alarmist claims made by Lovelock and others. A Melbourne academic, Dr John Reid, believed that something should be put into the water to make people infertile. He also suggested that society would need to withdraw health care for the middle-aged and elderly.
English environmentalist George Monbiot called for "global revolutionary change" including the establishment of a "New World Order" led by a world parliament.
Another Australian academic, Associate Professor Barry Walters, called women who had children polluters of the planet and wanted to hit them with a levy and an annual carbon tax.
The U.N. meanwhile called on Australia to pay $7 billion a year as a carbon debt.
The alarmism became a cover to try to railroad through some radical policy objectives. It created an unhealthy political climate - the sceptics were right to challenge outlandish claims and to insist that the science be properly debated and assessed.