Forgive us our eco-trespasses: Environmentalism offers a message that goes beyond ill-founded anxieties over global damage

DO YOU believe in global warming? How alarmed are you about the thinning of the ozone layer? Does acid rain keep you awake at night? And does a decline in biodiversity fill you with fear for the world your grandchildren will inherit?

The chances are that you are, to some extent, worried about all of these things. Surveys seem to show that 80-90 per cent of the populations of all developed countries profess themselves concerned or very concerned about these big, global, environmental threats. Anxiety about what scientific and industrial civilisation is doing to the planet is one of the defining attributes of our age. The bland, technological optimism of the Fifties has given way to a condition of apocalyptic fear and suspicion. Once people might have coughed and mildly protested about a smoky car exhaust or belching chimney; now, smitten with visions of global heat death, they call Greenpeace or Friends of the Earth.

This is understandable. Powerful forces - scientists, lobby groups and politicians - have put their authority behind the conviction that the Earth is a limited system that can only take so much and we are perilously close to the limit.

But scientists, lobby groups and politicians put their authority behind many things. Usually they are ignored, laughed at, or, if they are lucky, taken seriously for a day or two. When it comes to the environment, however, everybody listens. Each new threat becomes another layer of long-term anxiety, a further intensification of our guilt at the despoliation of nature. This week, on BBC 1's Panorama, it was fear of the carcinogenic effects of electro- magnetic fields; next week it will be something else. Whatever the issue, overwhelmingly it is clear that we want, or need, to believe in our own ecological criminality.

The radically sceptical response to this is simple. As the writer Matt Ridley and others have been pointing out, the actual science behind the big environmental anxieties is nothing like as clear-cut as people tend to think.

First, global warming is still no more than a hypothesis. There is no conclusive empirical evidence, and what evidence there is remains stubbornly ambiguous. Recently published satellite findings, for example, seem to indicate there has been no warming at all. And, even at the level of theory, there may be fundamental flaws - the carbon dioxide in the atmosphere may already be absorbing all the radiation that can be absorbed, so the emission of more carbon dioxide will make no difference.

Second, the dying northern forests are a more complex phenomenon than previously thought and the initial impulse to put all the blame on acid rain caused by power station emissions has proved difficult to sustain.

Third, although the thinning of the ozone layer is well established and the implication of chlorine in this process is generally accepted, the real impact has been exaggerated. You will still be exposed to more ultra-violet on a Seychelles beach than in Antarctica. Sane scientists know that the ozone scare has got out of hand, but have tended to keep quiet on the basis that concern is better than complacency.

This points to the best general reason for scepticism about environmental claims. The environment has proved a bonanza for science. Atmospheric chemistry, once a scientific backwater, is now one of the sexiest and richest research fields. Environmental anxieties are big money, drawing out private, corporate and government funds. Many people and institutions have good, financial reasons for ensuring that you are scared. And all of this is combined with the dreadful paraphernalia of ecological political correctness. In the United States it has seriously been suggested that any evidence that tends to disprove the global anxiety theories should be suppressed. We know we are right, say these hard eco-freaks, therefore you must be wrong. It is the reasoning of the mad and the bad throughout history.

The complete sceptic might conclude from all this that the whole thing is an absurd conspiracy, fed by scientific greed, media hysteria and Stalinist political correctness. Environmentalists themselves repeatedly play into the hands of the sceptics by making wild forecasts that rapidly prove to be wrong. The prediction that the burning of the Kuwaiti oil wells by the Iraqis would destabilise the Indian monsoon was the most flagrant recent example.

Dismissing or lampooning the entire phenomenon on this basis is easy and fun, but wrong. Certainly there are elements of conspiracy, as well as greed, hysteria and Stalinism; and certainly the difficulty of obtaining conclusive empirical evidence is proving an increasing embarrassment to the environmentalists. But the theories alone have proved powerful enough to convince not only fanatics but also stable, wise and intelligent people. And, after all, it is quite clear that the modern pace of industrialisation is doing something big and unprecedented to the planet, so it is only reasonable to attempt to assess the seriousness of the side-effects.

But try this thought experiment. Imagine that tomorrow it was conclusively shown that global warming was a hopelessly flawed theory and/or that acid rain and the thinning of the ozone layer were nothing to worry about. Imagine, in short, that the scientific basis behind environmentalism collapsed. Would environmentalism itself collapse?

The answer, I think, is no. For our need and willingness to believe in the basic message of environmentalism is more than merely scientific. This is because the word 'environment' has expanded to include far more than the condition of the atmosphere or the state of our woodlands. It has become a statement about our relationship with nature and about a new and humbler perception of the limits of our powers.

In the Fifties, it was widely assumed that technology would provide an infinite number of mechanical solutions. Nuclear power would provide cheap energy, pesticides would increase food supply to meet population demands, and drugs would cure disease. All of these assumptions turned out to be too simple-minded.

The nuclear project failed and pesticides had unpredictable and catastrophic side-effects. Nature was too complex. For a time medicine survived untainted, but now Aids and the continuing intractability of the processes of human decay and disease have undermined its heroic, eternally hopeful place in the world.

In the Sixties, the idea of technology as more of a threat than a promise began to enter the popular imagination. This was intensified by the fact that, in spite of its obvious failures, technology was continuing to deliver economic growth. However mistrustful people might become of the fruits of science, it was still an unstoppable force that would transform the world whether we liked it or not.

Environmentalism filled the psychological vacuum created by the twin feelings of impotence and mistrust. It gave people something to do and a way of thinking that would express their disappointment and fear. At its worst it emerged as sanctimoniously radical politics; at its best it freed people of the dangerous illusion that they could do what they liked.

Now it is part of life. Children lecture their parents from the high moral ground of an eco-sensitivity they have acquired at school; politicians have turned a uniform shade of green; soaps and deodorants can barely be sold without some kind of environmental endorsement; I have been harangued by a child, watched by an approving mother, for filling my car with leaded petrol.

All of this is strange and much of it is silly. A good deal of it - such as my encounter at the garage or Anita Roddick's incantations over her Body Shop products - is intolerably priggish and meddlesome. But it cannot be dismissed and it is not going to go away for the simple reason that the fear and impotence that inspire it are not going to go away.

'A central characteristic of modern complex societies like ours,' writes Robin Grove-White of Lancaster University, 'is the way in which we have become more and more embedded as societies in massive technological and institutional commitments without any real processes of public decision.'

In other words: however much we may argue, vote or demonstrate, the feeling is that a big, international, inhuman logic will have its way with us whether we like it or not. This is as true of global electronic superhighways as it is of railways in the back gardens of previously solid Tory voters. Always there is a higher logic that mere human intelligence seems incapable of stopping or refuting. The natural and virtuous demands of locality, continuity or peace cannot be allowed to inhibit its progress.

This, far more than atmospheric chemistry or eco-friendly bubble baths, is what environmentalism is all about, and this, whatever the gyrations of the scientists, is what will keep it alive.