He was once a guru to environmentalists, claiming climate change would kill billions of humans by the end of this century.
But it seems James Lovelock has had a change of heart.
On the eve of a major environmental summit, he has attacked the modern green movement – declaring its theories 'meaningless drivel'.
Almost half a century after he revealed his Gaia theory, which inspired a generation of activists, the former Nasa scientists said he believed that rising sea levels were not a problem and that wind turbines were 'useless'.
The 92-year-old described the modern green movement as a 'religion', which used guilt to gain support.
Speaking about climate change, he said: 'I'm not worried about sea-level rises.'
He added: 'At worst, I think it will be 2ft a century.'
Slamming environmentalists, he said: 'It just so happens that the green religion is now taking over from the Christian religion.
'I don't think people have noticed that, but it's got all the sort of terms that religions use. The greens use guilt. You can't win people round by saying they are guilty for putting CO2 in the air.'
Mr Lovelock said he was a firm supporter of nuclear power and even voiced his support for fracking – the controversial process of extracting gas from rock deep underground, opposed by the green movement.
He said: 'Gas is almost a giveaway in the US at the moment. They've gone for fracking in a big way.
'Let's be pragmatic and sensible and get Britain to switch everything to methane. We should be going mad on it.'
In an interview, Mr Lovelock described existing theories of 'sustainable development' – a key topic for discussion at the upcoming summit – as 'drivel'.
He suggested that humans should instead use air conditioning to deal with climate change in cities, citing Singapore as an example.
He said: 'If we all move into cities, they become the equivalent of a nest. Then another thought comes immediately from that: if that's the way the flow is going, don't stop it, let's encourage it.
'Instead of trying to save the planet by geo-engineering or whatever, you merely have to air-condition the cities.'
Speaking about Singapore he said: 'You could not have chosen a worse climate in which to build a city. It's a swamp with temperatures in the 90s every day, and very humid.
Turnaround: Almost half a century after he revealed his Gaia theory, which inspired a generation of activists, the former Nasa scientists said he believed that rising sea levels were not a problem and that wind turbines were 'useless'
'But it is one of the most successful cities in the world. It's so much cheaper to air-condition the cities and let Gaia take care of the world. It's a much better route to go than so-called “sustainable development”, which is meaningless drivel.
Mr Lovelock, who has conducted research at Yale and Harvard universities, has been a respected member of the academic community for decades.
He discovered the presence of harmful chemicals – CFCs – in the atmosphere in the 1960s.
He developed the Gaia theory while working with Nasa.
It claims that the Earth has a self-regulating system which has automatically controlled global temperature, atmospheric content, oxygen, ocean salinity, and other factors.
But last month, the scientist admitted that he had been 'alarmist' and 'extrapolated too far' with his doomsday-like predictions on the effects of climate change.
His latest comments came just a week before the Rio+20 summit, a major conference on climate change, to mark the anniversary of the landmark Earth Summit in 1992.
New theory: Mr Lovelock said he was a firm supporter of nuclear power and even voiced his support for fracking ¿ the controversial process of extracting gas from rock deep underground, opposed by the green movement.