James Lovelock gives up science at 92, but his Gaia theory lives on

At the age of 92, James Lovelock is

finally leaving his life of scientific study and invention behind; a career that included the formulation of the Gaia theory, his highly influential hypothesis that Earth is a self-regulating, single organism. His personal effects, notebooks and equipment are being logged and archived ahead of entering London's Science Museum's collection later this year.

But leaning over a shoebox, rummaging for a cherished letter he received from Nasa in 1961 asking him to help it discover more about the Martian atmosphere, Lovelock doesn't appear sentimental. In fact, he appears relieved.

"Adapt and survive," he says. After more than three decades living amid acres of trees he planted himself in a wooded valley on the Cornwall-Devon border in southwest England, he and his wife, Sandy, have moved to an old lifeguard's cottage by the beach in Dorset. "I'm not worried about sea-level rises," he laughs. "At worst, I think it will be two feet [0.6 metres] a century."

Given that Lovelock predicted in 2006 that by this century's end "billions of us will die and the few breeding pairs of people that survive will be in the Arctic where the climate remains tolerable", this new laissez-faire attitude sounds like that screeching handbrake turn. Indeed, this year he admitted in an interview that generated mocking headlines such as "Doom-monger recants", that he had been "extrapolating too far" in reaching such a conclusion.

But Lovelock is relaxed about how this reversal might be perceived. Being allowed to change your mind and follow evidence is one of the liberating marvels of being an independent scientist, something he has revelled in since leaving Nasa, his last full-time employer, in the late 1960s.

He says it will be the topic of his latest book, due out next year, which has the working title Adventures of a Lone Scientist. He smiles: "My publisher keeps telling me: 'Can't you do a more cheery book this time?'."

Moving house has handed Lovelock the chance to pore over the everyday objects resulting from his life's work, most of which have been in the attic for decades. He picks up an undated invitation to UK intelligence service MI5's Christmas dinner. In his other hand, he holds an old envelope stamped "On Her Majesty's Service: Top secret". There are get-well cards from the likes of astronomer Carl Sagan, sent when he had heart problems in the early 1980s.