Humankind will be nearly extinct by the end of the century and there is little we can do but prepare for the worst, says James Lovelock, the scientist famed for his Gaia hypothesis of earth science.
"Before this century is over billions of us will die and the few breeding pairs of people that survive will be in the Arctic where the climate remains tolerable," warns Lovelock in today's Independent newspaper.
"Each community and nation must find the best use of the resources they have to sustain civilization for as long as they can," he says.
His warning reads like the plot outline of a classic science fiction tale like Olaf Stapledon's Last and First Men, in which the rise and fall of not mere civilisations, but species of man is charted over millions of years.
It is in fact the plot outline of Lovelock's own book, The Revenge of Gaia, in which he proposes that many of the earth's species will become extinct as global warming gathers its own runaway momentum.
But the idea is the same: desperate conditions eradicate humankind and those few people who survive have to start all over again, as though they've thrown an unlucky dice in a game of evolutionary snakes and ladders.
He's a sweet old man, Lovelock. At 86, he is still hopeful that the last ten thousand years of civilisation's sustained flowering have not been in vain. As well as "powering down" western civilisation and learning to live on more meagre rations than those to which we have grown accustomed, we should do what we can to preserve our knowledge for future generations, he says.
To do this, all the world's accumulated scientific knowledge should be stored away on special, long-lasting print and paper.
It is an idea that evokes another classic science fiction tale, George R Stewart's Earth Abides, in which humankind is indeed reduced to a few motley pockets of blinking survivors. The hero - a former geologist, as it happens - tries in vain to preserve the civil traditions and sustain some semblance of scientific progress.
The proto-civilisation he helps spawn from the dregs of the last is savage, ignorant and certainly cannot read, even if it did have any interest in reading about the scientific advances of a past civilisation.
In other words, unless you have a pass to an underground bunker in the Nevada desert, you have only two courses of action: enjoy it while it lasts or help "power down" our guzzling civilisation so it won't have all been in vain.®