OTTAWA - James Lovelock, one of the world's most revered environmentalists and scientists, has admitted to being an "alarmist" about climate change.

Lovelock -- whose books predicted billions of people would be dead by the end of this century because of global warming and the last "breeding pairs" of people would have to live at the polar regions -- now admits he went too far.

The 92-year-old now says his warnings were too alarmist, and that he and many others, including former U.S. vice-president Al Gore, were "extrapolating too far" from computer models.

"The climate is doing its usual tricks. There's nothing much really happening yet. We were supposed to be halfway toward a frying world now," he told MSNBC.

"The world has not warmed up very much since the millennium. Twelve years is a reasonable time ... it (the temperature) has stayed almost constant, whereas it should have been rising -- carbon dioxide is rising, no question about that."

His public correction doesn't concern the Sierra Club of Canada.

"The science of climate change has never said that billions of people would be dead or that London would be underwater by the end of the century, but it is progressing more rapidly than the models were predicting," said John Bennett, executive director of the environmental organization.

"Mr. Lovelock never had it right in the first place, so his correcting it is a good thing."

Lovelock has written books about his "Gaia theory" that our planet exists as a single living organism.

He was also the first one to figured out how to detect CFCs that experts said were creating holes in the ozone layer,

The Queen has honoured him and NASA uses his inventions, but Bennett's not so impressed.

"He is not seen as someone who is an authority on climate change. He's more of a philosopher than a scientist. I don't consider him to be one of my heroes," he said.

Bennett still holds Al Gore in high regard, despite Lovelock saying he was being an alarmist too.

Gore's plight to educate citizens about climate change were the subject of the lauded documentary, An Inconvenient Truth.

"His presentation of the facts of climate change is relatively correct. There's a few errors in his film, but they were based on the best estimates at the time," said Bennett.

"He's the most knowledgeable and understanding of politicians in North America. He is one of my heroes."