We are nowhere near that situation. This week Ian Pearson, the climate change minister, announced plans for retailers to use a labelling system so that customers know which products, through their whole life cycle, leave the largest carbon footprint. Good idea. But the code will be voluntary, will take at least 18 months to develop, and, when it comes out, will probably be no more transparent than the information about sugar and salt in foodstuffs. Climate change is treated as a matter of private consumer choice, like eating lentils rather than doughnuts.

The truth is that, when it comes to cutting carbon emissions, our politics, our society and our economy are not fit for purpose. The Treasury-commissioned review by Sir Nicholas Stern argued that action to mitigate climate change "must be viewed as an investment, a cost incurred now and in the coming few decades to avoid the risks of very severe consequences in the future". But long-term investment - which always carries an element of uncertainty - is precisely what we are bad at. Like children, we prefer £1 today to £2 tomorrow; and, even more, we prefer it to £5 we won't be around to collect a century hence.

Nearly every postwar British government has neglected investment for consumption. New Labour has done better, but largely by using the private finance initiative which, in effect, piles the costs on to future generations. Private consumers, in both Britain and America, have steadily accumulated debt, as well as leaving it to their children's and grandchildren's earnings to finance their pensions and care in old age. Business is dominated by "shareholder value": minimising costs and maximising returns so as to ramp up the share price without regard for a company's long-term health. In short, our entire way of life is chronically short-termist. This explains why America, which you'd expect to leap at the high profits that could eventually be made from developing green technology, has been so reluctant to support action. As far as corporate America is concerned, the short-term costs are too high, the returns too far in the future.

Stern, by phrasing the argument in terms of conventional economics, hasn't really helped. If we don't act now, he argues, climate change will cost us more in the future. He applies what economists call a social discount rate of less than 1%, which means, roughly speaking, that if we pour resources into cutting carbon emissions now it will seem money well spent in 50 or 100 years' time. Critics protest that the rate is too low because our grandchildren will be richer than we are and, therefore, better able to afford action against climate change. This essentially technical argument misses the point about global warming, which is that, if we continue polluting, it will eventually be impossible for humanity to avoid disaster, no matter what the resources at its disposal. Some people choose not to insure their houses, calculating that, in the event of fire, they have sufficient resources to pay the rebuilding costs. But what if there are no bricks or cement left? That, if climate scientists are right, is analogous to the situation humanity could face by the end of the century.

Politicians have little difficulty with some solutions to global warming. Prohibitions, raising taxes and bossing us around come naturally to them. Unfortunately, they call for sacrifice at exactly the moment when public trust is at an all-time low. Any proposal that might help cut carbon emissions - road-pricing, say, or waste recycling - meets strong opposition from vociferous lobbies. Even phasing out high-energy lightbulbs is resisted on the grounds that the equivalent low-energy ones are a bit dim and old folk might fall down the stairs. It's all very well for Stern, a clever economist, to talk about social discount rates. But how does he factor in grandma's refusal to grope around in poor light for a few seconds rather than protect her great-grandchildren from the risk of drowning next century?

In any case, grandma might object, using 80 watts less when she switches the light on won't by itself save the world, but it could easily kill or cripple her. Isn't what she does insignificant against the rising emissions of a billion Chinese? Grandma has a point. The same politicians who demand that we fly on fewer overseas holidays or turn down the heating continue to build roads and airports. They do so because they fear Britain will otherwise become uncompetitive and then the Chinese will take all our jobs and money.

Behind our thinking about global warming lies an unspoken assumption: that, in the end, science and technology will rescue us. Perhaps we shall launch giant reflectors into space to protect us from the sun's rays. Or discover new ways of growing food so it won't matter if half the world's agricultural land turns into desert. More plausibly, we may find a new source of low-cost, low-emission energy. As Bush reiterated yesterday, America has most faith in technical fixes, and at least he is honest about it. But it is the biggest illusion of all. Science and technology haven't delivered on half the promises of the past 50 years. We don't have a cure for cancer. We don't have robots to do the cleaning. We can't take holidays on the moon. And we still haven't found a way to harness high-temperature superconductivity which, we were told 20 years ago, would cut energy waste by half.

I am no scientist, and the climate change sceptics could, for all I know, be right. I would have more faith in them if they could decide exactly what they are being sceptical about. Is global warming not happening at all? Or is it down to sunspots rather than human activity? Or can we rely on the market to come up with the answers? Sometimes, all three arguments are presented simultaneously.

No, I am not the sandal-wearing fanatic of sceptic legend, wishing my dismal lifestyle on everyone else. I burn coal fires in winter, I'm off to New Zealand this year, and I estimate my home has a hundred electric light bulbs, though they're not all on at once. That's why I don't hold out much hope. Having been convinced that global warming is a genuine threat, I still think, deep down, that you only live once and my own carbon footprint won't make much of a difference. Which is just what everyone else thinks.

· Peter Wilby is a former editor of the New Statesman.

peter.wilby3@ntlworld.com