By SARAH SANDS

Last updated at 00:34 22 March 2008

Apocalypse, now! James Lovelock says the world is about to change

The weather forecast for this holiday weekend is wildly unsettled. We had better get used to it.

According to the climate change scientist James Lovelock, this is the beginning of the end of a peaceful phase in evolution.

By 2040, the world population of more than six billion will have been culled by floods, drought and famine.

The people of Southern Europe, as well as South-East Asia, will be fighting their way into countries such as Canada, Australia and Britain.

We will, he says, have to set up encampments in this country, like those established for the hundreds of thousands of refugees displaced by the conflict in East Africa.

Lovelock believes the subsequent ethnic tensions could lead to civil war.

Crackpot or visionary, the fact is that more and more people are paying attention to Lovelock, and that he, himself, supports the Intergovernmental Panel on Climate Change (IPCC) - the influential group who shared the Nobel Peace Prize with former American vice president Al Gore for their campaigns on global warming.

Lovelock also says that Margaret Thatcher and the Queen are "sympathetic" to his views.

He has been proclaiming his Gaia Theory for a generation. This states that the Earth is a living, self-regulating system and that by filling its atmosphere with CO2 (carbon dioxide emissions) we have destroyed the balance and overheated the planet. We are in the phase when the thermometer suddenly shoots up.

Lovelock believes it is too late to repair the damage. Government targets are "futile". Britain contributes such a tiny amount of emissions compared with countries such as China that our self-regulatory measures are pathetic.

"Everyone could burn coal all day and drive around in 4x4s and it would not make a scrap of difference," he says.

It is hubris, he argues, to believe we can prevent the inevitable consequences of mankind's actions. Lovelock reminds us - in case it has slipped our memory - that the Earth has gone through exactly the same correction before.

"It was last as hot as this 55 million years ago. There was a geological accident in the North Sea, near where Norway is. A volcanic layer of lava came up underneath one of the large petroleum deposits. It vaporised the whole lot, putting into the atmosphere about two million, million tons of crude oil.

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Challenge ahead: Rising sea levels will threaten central London by 2004, says Lovelock

"We will have put that much into the atmosphere within the next 20 years or so. We know what happened last time, we know how long it lasted. It hung around for about 200,000 years."

It may have been primitive creatures rather than people who were landed with the problem last time round but their survival strategy was instructive.

"Everything moved to the North," Lovelock explains. "The Arctic Ocean was tropical, the sea temperature was 23C (73F). You could find the remains of crocodiles in the sediments."

Such a residue of the past has guided Lovelock through his decades of investigation. The prophet of doom is a distinguished scientist, who was made a Companion of Honour and who has a great invention to his name.

He perfected the Electron Capture Detector which sought out poisons in the atmosphere and discovered CFCs puncturing the ozone layer, as well as pesticides.

He is now a sprightly 88-year-old, with infinite curiosity and lives with his American second wife, Sandy, who is 20 years his junior, in a modest farmhouse in the middle of a nature reserve of about 35 acres in Cornwall. He has four children and nine grandchildren.

He does not look like a man willing our extinction. Yet he says he welcomes the next evolutionary step - even if he is a victim of it.

He is convinced that something momentous is about to happen. The signs are evident even in his own nature reserve.

"The place is growing visibly more like a jungle, there is growth of brambles and spreading vegetation. Brambles, unlike their traditional English meadow image, are just the start of the takeover of jungle vegetation."

Lovelock expects the same changes among wildlife. "Polar bears will not become extinct, they will just go back to what they were, which is brown bears."

Nature is adapting to the changing climate and Lovelock argues that humankind will have to do the same. We will face a ruthless period of natural selection.

"I reckon there are about 80 per cent more people than the world can carry," he says sanguinely.

Geography will play the largest role in survival. By chance, Britain is well-placed for the new hot phase. An effect of the changes will be the end of the Gulf Stream which keeps Britain warm.

So the climbing temperatures will be countered by cooler water. However, our European neighbours will not be so fortunate. "A lot of people who come here will be Europeans," predicts Lovelock.

"If you take the IPCC predictions, then by 2040 every summer in Europe will be as hot as it was in 2003 - between 110F and 120F. It is not the death of people that is the main problem, it is the fact that the plants can't grow. There will be almost no food grown in Europe.

"By 2040, parts of the Sahara desert will have moved into middle Europe. We are talking about Paris. As far north as Berlin. In Britain we will escape because of our oceanic position."

But Britain will not be entirely unaffected. According to Lovelock, rising sea levels will threaten central London, Cambridge and Somerset.

"We should do what the Dutch have done, and build a sea wall - or abandon the middle of London and have it as a lagoon city. Parliament and the City could relocate to higher ground."

The consequences of climate change are a science fiction nightmare. The writer of Dr Who, Russell T. Davies, once told me the only plot he would avoid was the environment because he could not give audiences a happy ending.

Yet Lovelock contemplates catastrophe almost with excitement. I ask why is he not terrified.

He answers that he has never lost a single night's sleep over the future. Scientific interest overcomes self-interest. He has a humility about the place of humans in the 3.5 billion year lifespan of the Earth. He talks not of people but of "our species".

He passionately wants "the best of our species" to survive, and is philosophical about the majority who won't.

"It will be a challenging and difficult life ahead but it will bring out the best in us. It will bring the most awful problem for our people and our Government.

"At some point, we are going to have to say Britain is a lifeboat. If any more people come on board then we will sink.

"If we get it wrong, you will have ghastly encampments like Darfur. People will be smuggling their way in and setting up camps. Ethnic communities will want to help them and civil war will start."

However, immigration is also a natural form of selection, he argues. Those who are prepared to travel will be the survivors.

"We should be selective and those brave, enterprising healthy people coming over in cockle boats from Africa should be the first we let in.

"I think we will have to be rough on people of my age. But I have lived a darn good life, why should I grumble? One shouldn't be a freeloader."

He admits he cannot mourn for people he does not know. Selection is already happening. "Nations are selecting who they allow in. We are a soft touch in the UK compared with Australia."

As nationals move to escape catastrophe, new forms of colonisation will occur. Lovelock believes that the current Chinese economic interest in Africa is part of a greater plan.

"By 2040, China will be uninhabitable." Lovelock believes that the Chinese, because of their high levels of industrial activity, will be the first to suffer, with the death of all plant life.

"So I think the Chinese will go to Africa. They are already there, preparing a new continent - the Chinese industrialists who claim to be out there mining minerals are just there on a pretext of preparing for the big move.

"This is not science fiction. Mr Putin will colonise Siberia. Those who will have a very rough time are those in the indian subcontinent. You don't need much of a sea level rise to wipe Bangladesh off the face of the Earth."

Australians have enough land and resources to stay put. Lovelock sees Americans moving to Canada. Americans have the natural advantage of being born migrants.

"White Americans are descended from those who had the guts to cross on rough old ships and find a new life. They have the right spirit of can-do."

Lovelock is more concerned by the American tendency to believe that everything can be fixed. He says that he agrees with George Bush that it is technology rather than conservation that is needed to tackle climate change, but he is uneasy about technology's unintended consequences.

"Technology is neutral. There is good and bad. It was technology that got us into this mess. The name of the game is consequences. I will take a bet that if climate change gets really bad in America, not only will they buy land in Canada, but they will be saying: we can fix this.

"America claims it already has a solution ready - it wants to mimic the effect of a volcano, and shoot volcanic heat into the atmosphere.

This will lower the temperature - the clouds of sulphur gas and ash will soak up the sun's heat and reflect sunlight back into space.

"You would need about 20 million tons of sulphur, not an awful lot. Airlines could easily put it up there. The effect would be to re-adjust the heating and give you a status quo.

"But it is a bit like kidney failure - you can live a bit longer on dialysis but it may have side-effects. In this case, the sea could turn to acid. You can't come in and expect a complete cure."

Eager to show my survivalist instincts, I suggest that "our species" finds another planet to inhabit. Lovelock's face darkens.

"No, we can't," he says. "There isn't one. And it is almost obscene, the idea that you screw up the Earth and then look for another planet. We have no option but to take our punishment and be glad that there will be enough of us to survive."

At least the scientific establishment sees James Lovelock as a maverick. Yet he has influential converts. Firms such as Shell have consulted him about his theories. Prince Charles has invited him to lecture at his summer school this year.

In 2004, Lovelock had an animated exchange with the Queen. "Naturally, she had done her homework, and she led the conversation. I was surprised by how much she agreed with. I found her in sympathy and aware of what is going on."

An earlier convert to his dramatic views on climate change was Margaret Thatcher. "She was partly turned by Sir Crispin Tickell, who was our ambassador to the UN. He and I share views on climate change closely."

I ask if Lady Thatcher could have saved the world had she acted more decisively. "You couldn't have stopped the evolution of Chinese industry. We have to stop thinking it is all our fault. We could have stopped it if we had all listened to Malthus in 1800 (the economist who said population would outstrip agricultural supply).

"Everyone laughed at him, but he was right. A billion is about the right number of people for the Earth. We are nearly seven billion. Had we stayed at a billion we could have done whatever we liked with technology and there would have been no problem."

Although Lovelock lives in isolation among his many acres, he feels the loss of space in Britain acutely.

"I was brought up in Brixton in South London, and you were in the country by Orpington, 14 miles away. It was open land all the way to Portsmouth. You've no idea how glorious this country used to be."

So we have over-reproduced and are now engaged in a frantic and, according to Lovelock, futile exercise in damage limitation. All our low-watt light bulbs and electric cars are doing no good, and may aggravate the situation further.

"Bali (the latest international climate change agreement) may make things worse. One peculiarity is that when you burn coal and fuel you not only put CO2 into the atmosphere, which makes the Earth warmer, but you also put out a lot of dust and haze, which acts as a screen and cools the Earth."

So, if there is an economic downtown and there is less industry in China, global warming could worsen.

Meanwhile, Lovelock says: "European governments are doing daft things, investing huge sums in renewable energy which makes a hell of a lot of profit but does no good at all for our survival."

The secret is to adapt as best we can - and to take the long view. The Earth is elderly, 3.5 billion years old and with another 500 million to go. The sun has another five billion years to go, before it turns into a "white dwarf" - a lump of rock.

"It is like the flashlight on a torch," explains Lovelock. "The battery will eventually run out. Everything is mortal. I would not want everlasting life for myself or for the Earth.

"We are about to take an evolutionary step and my hope is that the species will emerge stronger. It would be hubris to think humans as they now are God's chosen race."

No one can accuse the scientist of the Apocalypse of being gloomy.