For many years now, the inventor and ecologist James Lovelock has been saying that Mother Ship Earth is heading for disaster. Unfortunately for James, he rather unwisely chose to brand his theory 'Gaia', and present the Earth as a living entity. He now claims this was never his intention, but either way two things resulted: first, concerned folks like me immediately placed him firmly in the Wacky Camp; and second, people who really do belong in the Wacky Camp flocked to his support. Thus Professor Lovelock found himself in the territory of ley lines, levitating Albert Halls, women who wear large boots, and the folks recycling their farts in between making beetroot wine.

In fact, Lovelock is quite an authority on farts. Breathing and farts (he quite rightly points out) are - if you add in our pets and livestock - almost half of all those nasty CO2 emissions. And the last thing he'd suggest is cooking on farts, as that'd make the pollution even worse. In his new book The Disappearing Face of Gaia in fact, he does what nobody else has bothered to do so far: he tots up the results of Homo sapiens and all its works, and reaches the conclusion that almost 90% of all greenhouse effects are down to us.

The evidence is compelling. But the other reason why Lovelock has been rebranded and placed in the mainstream is that just about everything he said would happen is coming to pass - only much faster than even he thought. In at last from the wacky wilderness, James is now a hero and lauded by people who said they always felt that somehow he might have a point.

Having been through a similar repositioning myself over the past two years, I empathise very much with the frustration of being the lone voice of seeming insanity. The scale of my insight however (that all bankers and banking systems are mad and/or crooked) is as one part of methane per million compared to the planetary scale of this eccentric man's soothsaying. He is to the ecology issue in 2009 what Barnes Wallis was to the Dam Busters in 1943: somebody perceived at first to be bonkers, but now recognised as the genius he always was.

In this his last effort (he is ninety now and calls it 'A Final Warning') the Professor adds two enormous things to the sum of human knowledge about, and comprehension of, the effect of Man on climate change. First and foremost, he levels with us about the effect of rising temperatures and sea levels, in that they will knacker our crops and remove most of our land respectively. And second, he makes it bluntly clear that not only are most governments in denial about the need for haste, but also that most 'Greens' are wittering on about things of supreme irrelevance. I hate to say this, but as nby wrote in Satellite View eighteen months ago, there are too bloody many of us - and that is just about the beginning and end of the problem.

Being a good person and card-carrying liberal, Lovelock doesn't draw the obvious conclusion from the mathematics of 7.5 billion into one Earth won't go. In fact he even goes as far as to expect that the British Isles - where things could easily be if anything rather better than they are now - will become a philanthropic 'lifeboat' (his word, not mine) for the multitude of unfortunates in dire need of dry land, food, and a conditioner to take the sea-salt out of their hair.

My own view would be that even our Sceptred Isle's current state of relative overcrowding is far too cosy for the liking of the vast majority of Brits. Liberal or otherwise, a disturbing proportion of people I quite like would be turfing more than a few currently in the lifeboat out, not inviting more in. And I'm afraid I fundamentally disagree with James's optimism about all these horrendous climatic events simply occurring without anyone taking drastic action. Once the maths are completely undeniable (at this rate, in about five years) everyone in authority will start doing something about it, and pretty damn smartly.

So let's get off the pot and give the C-word its oxygen of publicity: the word is cull. And while you're recovering from that, let me take you back to a time when quite a few of you weren't born, and the threat to humanity (rather than its likely saviour) was nuclear. In 1959, the British Government issued a pamphlet and information film called Protect & Survive. The poor devils who wrote and scripted this epic were on to a loser from page one, given that anybody without a fully-functioning nuclear bomb shelter would've had no hope of protection or survival if global nuclear war had ever broken out. But even allowing for this, the desperately clutched straws suggested in P & S were hysterically funny even then. They're so thigh-slappingly daft when viewed from the perspective of today, a burst aorta could easily result from watching people taking doors off hinges and hiding under them, all the while stuffing garbage bags in behind them as they settled down for a twenty-year Nuclear Winter.

The point is this: as and when the eco-population tipping point approaches, you can be entirely confident about three things. One, the advice from our masters will be twaddle. Two, it won't tell you anything about what's really going to happen. And three, what's really going to happen is that they'll survive, and we won't. If you need further reassurance about this, I recommend you look at the declassified documents from 1960, showing with stark honesty how every last useless senior Minister, Military Top Brass and Civil Servant had booked a place in the bunker - leaving the population to the garbage-stuffed door-tent experience. (The only consolation, by the by, is that the Nobs wouldn't have survived either: nobody had thought to allow for the effect of shock waves on an underground ventilation system; thus within ten minutes of postwar peace being declared, most of the occupants would've been wearing a face full of conduction slats and breathing pure Strontium 90.)

Anyway, there we have it: the cull cometh - and those in charge are unlikely to cull themselves. So the teaser is, how might it be done? And the short answer goes 'there are lots of alternatives'.

At the risk of sounding like Jeremy Clarkson on one of his more unpleasant tangents, by far the fastest way to both cool the Earth down and at the very least halve the population would be to have an extensive nuclear conflict. It would take in the region of thirty 100 megaton H-bombs to cover the Earth in clouds for about five years. The downsides of this are that (a) this would kill almost every photosynthesiser on the planet (b) the radiation would hang around for a few decades and (c) almost none of the Russian missiles would work. Many would view this last as a distinct plus-point, but overall, the rules of engagement would be a tricky thing to agree on. It's a quick-fix solution your thermo-nuclear war, but one of those that just as quickly becomes next year's problem: weighing up the Sod's Law balance, one could see several ways in which - even without the three issues raised above - we'd probably wind up in an even bigger mess than the one we're in now.

Thinking more laterally, one could keep the cull to a minimum by sterilizing lots of people. The maths of population are extraordinary when it comes to a species, but the bottom line is that at existing levels of licentiousness, this would reduce our numbers by about 30% over six years. While here again one faces the obvious dilemma about who gets snipped and who doesn't, just imagine the fun you could have deciding: Max Clifford, Didier Drogba, Pete Doherty, Christiano Ronaldo, Robert Mugabe, Mahmood Ahmadinnejad, Paris Hilton, Naomi Campbell, Freddie Goodwin....on reflection, perhaps the difficult bit would be deciding where to stop.

But doing this sort of stuff has a poor track record. They tried it in China for two decades and then gave up. Given that the strongest human instinct is the reproductive one, you can sort of see why; and even on a crowded planet there are still lots of places to hide when the men in white coats come calling. Also - looking at that list above, you just know that the biggest jerks would find a reason for exemption. I mean, what's the point of goolie-chopping if you can't bag a brace like Tony Blair and John Prescott?

Cannibalism has a lot going for it as a potential solution*. Vegetarians and moralists would have a bit of a whinge, but you know, Eating People is Wrong looks kind of dated these days. Those people who crashed into the Andes, they ate the dead passengers - and at that height, there's no need for a freezer: just stroll into the nearest fuselage, hack off an arm and start chewing. Not only will it stave off starvation, it has the unique double-benefit of Cull While You Eat.

The Government posters write themselves: Eatanarseholeeveryday, Save the Planet - Chomp on a Chump, Put a Yob in your Gob and so forth. You can see the marketing strategy here: 'Tired of ineffectual ASBOs and Speed Awareness Courses? Simply eat the bastards: you know it makes sense'.

Unfortunately, James Lovelock has managed at long last to give a truly sensible reason for being vegetarian: you fart less (although for me, that's counter-intuitive) and you don't need all those windy cattle where the trees should be. As most humans in the West are obese, the result of such a high-fat cannibal diet would be both more frequent and far more venomous farting by those not being eaten; thus in the short to medium-term, it wouldn't make enough difference - and as Prince Charles has lately pointed out, time is of the essence.

Which leaves just the asteroid hit and the pandemic as Armageddon options. The former is beyond our control anyway - and the cure would probably kill everything bigger than shrews and tundra - but the idea of bio-chemical warfare has been around for over half a century. Also, although everyone denies having any of that nasty anthrax stuff any more, the stronger and more affronted the denials become, the more certain you can be that they've got mountains of deadly poisons secreted away.

Although this isn't the sort of thing we're going to hear David Miliband boasting to the Commons about (and if he did, nobody would believe him) Britain is actually something of a world leader in the field: what's more, things have moved on in terms of the two vital success factors, accuracy and antidote.

Accuracy was something of a problem with the early bugs, because anything wind-borne could (given the almost certain inaccuracy of weather forecasts) literally come back to bite one - and water-borne nasties tended to prove that water gets into all kinds of unexpected places. But these days, they have short-life things that leave nice clean corpses and rapidly disappear when launched into a water supply - another bonus if one wants to stand up in front of the Commons and deny something. We're back to Miliband again, and twice in one day is more than enough. Suffice to say that in 2009, you can drop one minute pipette's worth into the Harare Presidential Palace, and render everyone lifeless inside ten minutes - with the kind of certainty one needs when attempting to kill tyrants.

A is also for antidote. Early research in this field** confirmed fears that certain viruses, once launched, might be something of a Pandora's Box. That is, the strain one makes can too easily mutate into something else. So it's vital to have an antidote - and preferably (if you think about it for more than a second) to have a virus that gets bored after the first round and dies off. Believe it or not, there is a field of research called viral mortalicizing which aims to ensure exactly this. The gargoyles who make this stuff then hand it on to Antidote & Declan, and they design the cure. It's amazing what humans can achieve when they go absolutely and completely off the rails and round the bend.

While there is an International Accord on promising not to do this sort of thing (it works mainly because, like nuclear weapons, nobody fancies the retaliation much) we are almost at that point in history where 99% of the rules are about to be ignored. So in short, the man-made pandemic looks favourite at the moment. Not only does it offer the chance to make the culling choice easy (ie wipe out the enemy, and then stop) it can also be very easily disguised as God moving in a mysterious manner. You'd have to pretend that your own people were dropping like flies too, but then under certain regimes the role of dying person could be played by the sort of unwilling volunteers we call dissidents, and they call terrorists. As recent incidents in Tibet have demonstrated, this isn't hard to orchestrate.

Happily, there are signs that it may not be necessary for any of the established C-words to carry out a future C-word: for despite the almost entirely doomsaying press Lovelock's new book has had, the last hundred pages are spiced with a smattering of cautious optimism. And as you'd expect with a science professor, he thinks science just might come up with at least one viable solution.

James' ideas include gigantic umbrellas placed between us and the sun, messing with oceanic algae, enormous pipes sucking cold water up from the ocean depths, plus some others that frightened me a whole lot more than being crammed onto a small island while intermittently pouring boiling oil on the starving hordes below. As to whether or not Lovelock's ideas are the right ones, I haven't a clue. But compared to the chest-beating, spin-ridden drivel being put out by word leaders, his observations do at least have a sense of urgency and reason.

I retain my own perhaps misguided faith in human ingenuity to get us safely past this latest human crossroads - if only because (as a historian) the past tends to suggest it. But as many investors are discovering too late, the past is no guide to the future. Either way, the chances of us pulling it off have been massively increased by Lovelock's words. And for that, we owe him an enormous debt of gratitude.

* Before you dismiss the thought as the gratuitous output of a diseased mind, I should point out that this is exactly what happened on Easter Island aeons ago. There were too many people and not enough fruit, veg or wildlife: so they ate each other in a series of grisly Grande Bouffes. It didn't work: the gene pool got too small, and they died out.

** You may wonder how I know all this stuff, but trust me - you don't want to know. Also telling you would lead to certain death at the hands of the Forces of Darkness. Especially for me.

Home