LONDON, England (CNN) -- James Lovelock refers to himself as a "planetary doctor."
"Humans always think of these things in grand terms." Lovelock is philosophical about the climate crisis.
As someone who has studied his patient for over 40 years, the 88-year-old scientist and originator of Gaia theory, has reached a bleak prognosis: the world as we know it is ceasing to exist.
The impact of humanity has set in train processes that, according to Lovelock, are irreversible.
Pollution, overpopulation and carbon emissions have already pushed the earth's delicate regulatory systems beyond the point of no return, he says, and steps to address the climate crisis can do no more than slow down the inevitable.
"What we did was to pull the trigger in all of those things and set in course a motion, a change in the Earth, which is to all intents and purposes unstoppable," he tells CNN.
The legacy for future generations is a world where droughts and extreme weather are commonplace, large portions of the planet are turned to uninhabitable desert and billions of people destined to die off.
He has predicted that by 2040 the Sahara will be encroaching on Europe, and by 2100 there will be only 500 million of us surviving close to the poles.
It is a grim account of what's in store, and at odds with a large portion of scientific opinion that contends that if we take action now to cut carbon emissions, we can at least mitigate some of the worst effects of climate change.
So why should we take notice of him? Well, for one thing history is on his side: The British scientist's seemingly fanciful assessments of our world have proved right in the past.
In the 1960s he came up with a revolutionary understanding of how the world works. All living things, he theorized, have a regulatory effect on the Earth's environment, working together as one complete "superorganism" to sustain life.
In other words, life itself creates the conditions for life.
This holistic view of the planet he named Gaia after the Greek goddess of the Earth on the suggestion of his neighbor at the time in the English county of Wiltshire, William Golding, the author Lord of the Flies.
At first embraced by the New Age and environmental movement but almost totally ignored by the scientific community, the essential truth of the Gaia hypothesis -- that the Earth regulates itself -- has since been adopted by the scientific mainstream.
"It's a top down view of the planet looking at it as a whole system, and science unfortunately in the last century divided [the study of the earth] up into numerous specialties," he says.
According to Lovelock, this is why his predictions on climate change are more extreme, but also more accurate than those of leading scientific bodies like the Intergovernmental Panel on Climate Change (IPCC), which he claims is limited in its assessment because it is made up of specialists whose focus is too narrow.
"The IPCC is made up largely of atmospheric physicists who are good at predicting the weather, but I'm not so sure that they are very good at predicting the future of the Earth.
"Likewise, the biologists who should be working with them are working separately and have produced the Millennium Ecosystem Assessments Commission's report and that's quite different from the IPCC and it's mostly concerned with biodiversity and things like that."
Although he offers some points of light -- putting an aerosol layer of fine particles into the stratosphere to reflect back sunlight may, he says, could buy us some time by slowing down the rate of decline for a decade -- his projections are on the whole brutally pessimistic.
Oddly however, he insists that he is himself an optimist by nature.
Listening to Lovelock it is easy to see why his theories caught on with New Age thinkers -- there is a strain of spirituality in much of what he says.
He's philosophical about the extinction of the human race, for example, viewing it as just another stage in the Earth's life cycle.
"Humans always think of these things in grand and big terms, rather than as part of the natural course of events. There are all sorts of organisms that have evolved on the earth in its long, long four billion years of history.
"For example, organisms like the photo-synthesizers appeared and, ultimately turned the atmosphere into one with lots of oxygen in it ... all sorts of dreadful things must have happened when that change took place.
"What we're doing is small beer compared with what has happened in the past, and that's why the earth is so robust and strong and will cope with it."
As an environmentalist, he is also surprisingly upbeat about humanity in spite of the apparent mess we've made of the planet.
Without realizing it, he says, humans set into motion a train of events we didn't realize we were in no position to control.
"We're a wonderfully valuable species to our planet," he says. "You see the great system has existed all those years and for the first time ever it's had people talking about it, and we're part of it, you see. So it's beginning to understand its position in the universe."
Humans may face an uncertain future but Gaia, it seems, will live on. E-mail to a friend