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New Statesman Millennium - Will humanity survive the next millennium? Scientists calculate

The future was looking quite prosaic until the 20th century came along. With careful, painstaking steps, scientists thought they had cracked just about all the universe's codes. There had been steady moral advancement since the Dark Ages. It was almost possible to extrapolate linearly to Utopia. Then came what Isaiah Berlin called "the most terrible century in western history". We contemplate the next thousand years conscious of things that the Victorians could not have imagined in their most lurid nightmares.

In his novel Galapagos, Kurt Vonnegut makes one confident and hopeful prediction about the future of the human race. Even when we have evolved into an endangered species of finned, aquatic creatures marooned on the Pacific archipelago, we will still find farting funny. In Utopia of a Tired Man, Jorge Luis Borges sees it differently: "There is no reason to carry on the human race . . . The advantages and disadvantages of gradual or simultaneous suicide by every man and woman on earth are, I believe, now being argued."

They are indeed, although you might not have noticed. How many multiples of a world-destroying arsenal do we need, now that non-proliferation is dead on its feet? What happens when world water demand exceeds the total available supply - as it will in two or three decades? How quickly will we return to a medical age before antibiotics, foiled by the Darwinian evolution of superbugs? How warm must it get before the Western Antarctic Ice Sheet slides into the Southern Ocean?

Yet some suicides are more subtle. If catastrophe does not intervene, our longevity as a species might fall victim to our own success. By the end of the next millennium, I believe we will know all that is worth knowing about the laws of nature and, moreover, we will be able to do with them all that can be done. We will be capable of things we'd now regard as magic, since, as Arthur C Clarke points out, this is indistinguishable from any sufficiently advanced technology. History will indeed have ended - yet with billions of years still to kill, our biggest enemy might be boredom.

It may seem hubristic (to say the least) to suggest that humans will have deduced all that can be known within just ten millennia of the first settlements being established in the fertile plains of the Middle East. Given the long history of life on Earth, it is rather like suggesting that it sat torpidly in an exam for three hours, and then answered every question in the last microsecond.

Yet the frontiers of knowledge are expanding too rapidly to permit any other conclusion. The objection that we may find our brains inadequate to accommodate all that can be known is redundant - there will surely be artificial ways to leapfrog such limitations.

One thing we will do quite early on, perhaps even within the next century, is to create life from scratch. I don't mean anything so mundane as making computers that think. No, we'll have built organisms chemically, all the way up from genes made of stuff other than DNA - or perhaps we shall bypass the whole genetic principle and find some other way for molecular systems to replicate and self-organise.

But will humanity, or more broadly, the intelligence that originated in humans, survive this explosion of knowledge? If you want to know about the next 50 years, ask a scientist; but for a briefing on the next thousand, consult a science-fiction writer.

Ian Watson, for example, speculates that, by 2105, thought-mail hard-wired into the brain will have erased all individual consciousness. Is this plausible? The brain is the next big frontier for science. At present no one has the faintest idea what consciousness is or how to explain it (whenever you see titles such as "Consciousness Explained", advance with salt cellar at the ready). We are as well equipped to write speculative stories about consciousness as H G Wells was to fantasise about trips to the moon. We are in danger of understanding everything about the brain except why we understand it, and there is an uneasy feeling that we are up against one of those Russellian self-referential paradoxes. In the words of the neurologist Antonio Damasio, "the mind is a private, hidden, internal, unequivocally subjective entity".

Yet if it is possible (as Damasio and others believe) to understand consciousness scientifically - which is, in the end, to say reductionistically - then I believe that will happen within the next century. And if there is nothing to it but sufficient complexity of neural connectivity, who is to say that consciousness could not then be downloaded? That, indeed, is what furnishes the sci-fi author Bruce Sterling with his tale of the extinction of humanity in the year 2380: Homo sapiens designs itself out of existence, as synthetic celebrities embodied in "gelbrain" comment coolly on its demise.

None of this seems as absurd today as it would have done just 20 years ago, when almost no one had heard of e-mail, let alone considered it utterly vital to their well-being. The speed with which electronic communication has spun its web over the world is the most sobering reminder of the almost instantaneous transforming power of information technology.

This gives the robotics engineer Hans Moravec the confidence to say that "by 2040 we will finally achieve the original goal of robotics: a freely moving machine with the intellectual capabilities of a human being". Moravec measures "intellectual capacities" in terms of mips: millions of instructions per second. Present-day computers typically function at almost 1,000 mips, equivalent to the brainpower of a guppy. An improvement by a factor of around a hundred thousand is needed to rival the human brain. Such artificial minds will be able to abstract and generalise and are likely to be far better at scientific research than we are. There is, then, the question of what these robots will think when they notice that humans are lagging behind as they expound their "Theories of Everything". At present, a mere twentyfold deficit in mips for monkeys compared with ourselves is deemed sufficient to justify our neurological experiments on primates. Robots, not humans, might solve the problem of consciousness - but we might not approve of their methods.

Meanwhile, there is an ever-lengthening list of doomsday options. I suspect that, if there were a cosmic ledger recording the histories of all intelligent life, it would reveal some correlation between the point at which civilisations are able to frame accurate questions about their future potential and their ability to curtail that potential abruptly. We ask our questions about the longevity of the species armed with the knowledge of how old the universe is (give or take a few billion years), when the world began, how natural selection brought us from jelly to Jeremy Paxman and so forth. And yet we also face the real prospect that nuclear war, superbugs, global warming or ecosystem collapse could return us to the Stone Age, or worse, within a century or so. The two situations are not, I think, coincidental.

One problem is that these threats involve timescales that do not exist on the political landscape. People are exercised about genetically modified crops because they fear (with varying degrees of justification) that they might be poisoned tomorrow, that farmers in developing countries might be in the thrall of multinationals within a few years, that Monarch butterflies might be extinct within the decade. But who can really grasp what it means that the sea level rose more in the past century than in the previous 20 centuries, or that it might stand a metre higher by 2100?

It is an oft-repeated accusation that politics is about short-termism - but so is our entire way of life. We can fret about dangers to humanity on a timescale of perhaps 50 years (oddly coincident with the upper limit on most of our projected remaining lifespans), but after that it becomes hard to take anything seriously. The very longevity of nuclear waste contributes, in an odd way, to its acceptance: the mind is dulled by the sheer geological magnitude of those half-lives.

We haven't adapted for thinking big. The panic, the grandiose fantasies, the awful movies that greeted the dawning realisation that life on Earth could be obliterated by meteorite impacts testify to this. What a hilarious joke it would be for our world to be sterilised by space rubble just years after we started looking out for it, while the past 65 million years have been as quiet as the desert night. But the consequences are so dramatic that the probabilities are powerless to maintain a sense of proportion.

Astronomers have thoughtfully provided a risk scale for comet and asteroid impacts. Magnitude one on the Torino scale reassures us that "the chance of a collision is extremely unlikely". Ten is the armageddon warning: "a collision capable of causing global climatic catastrophe." Yet armageddons of this order come but once every 100,000 years at most, while impacts that lead to certain global mass extinction happen every 0.1 to 1 billion years. For the next thousand years, we need not be too fearful of the skies falling; and by the time that is over, we will know how to lift them back up again.

J Richard Gott, an astrophysicist at Princeton University, has invoked the Copernican principle - the supposition that one's location is unlikely to be special - to place probable upper and lower bounds on our continued existence. The argument is deceptively simple, although statisticians debate furiously whether it is conjuring up knowledge from ignorance. If there is nothing special about our own situation in regard to human existence - if we do not have the dubious fortune of witnessing, say, the final 5 per cent of it - then Homo sapiens's 200,000-year history so far implies that there is a 95 per cent chance we will be here for between a further 5,100 and 7.8 million years. Plenty of comfort there, then. But Gott himself is less sanguine: "I would be more confident about the future if we were members of a billion-year-old civilisation that had already colonised its galaxy." (Who wouldn't?) But the chances that we will ever do this, with its implication of a billionfold population increase, are a mere one in a billion, since it would imply that we represent the highly atypical first billionth of all humans.

Personally, I don't think Gott reckons enough with our potential for transforming the very concept of being human. If we are still here in a thousand years' time, I don't think we will recognise ourselves.

The writer is consultant editor for "Nature" magazine. His "H2O: a biography of water" is published by Weidenfeld & Nicolson

This article appears in the 20 December 1999 issue of the New Statesman, Now then, are we getting anywhere?