It hardly needed explanation. 'Everyone knows the planet is in bad shape,' thundered a Time magazine article last year. The seas are being polluted, the forests devastated, species are being driven to extinction at record rates, the rain is acid, the ozone layer vaporising, and the rivers are so poisonous fish are floating on the surface, dead. As Al Gore, former US vice-president, put it in his book Earth in the Balance : 'Modern industrial civilisation is colliding violently with our planet's ecological system.' We inherited Eden and are leaving our children a depleted rubbish tip.
But there's a growing belief that what everyone takes for granted is wrong: things are actually getting better. A new book is about to overturn our most basic assumptions about the world's environment. Far from going to hell in a handcart, it is improving by almost all measures. Those things not getting better are getting worse at a slower rate.
Rivers, seas, rain and the atmosphere are all getting cleaner. The total amount of forests in the world is not declining, few species are being made extinct, and many of those that were endangered are thriving again. The Skeptical Environmentalist by Bjørn Lomborg, professor of statistics at the University of Aarhus in Denmark, is a scathing attack on the misleading claims of environmental groups, and the 'bad news' culture that makes people believe everything is getting worse, when by almost all indicators, things are getting better.
When it was first published in Scandinavia, it caused a deafening storm of protest, and transformed the nature of the debate. The book is part of a growing backlash against green groups, and potentially the most dangerous. Most previous criticisms have come from right-wing think-tanks hostile to the environment agenda.
Now the attacks are increasingly coming from left-wing environmentalists such as Lomborg, a former member of Greenpeace. The accusation is that, although the environment is improving, green groups - with revenues of hundreds of millions of pounds a year - are using increasingly desperate scaremongering tactics to sustain donations.
Lomborg's book, to be published in September by Cambridge University Press, doesn't deny global warming - probably the biggest environmental threat - but demolishes almost every other environmental claim with a barrage of official statistics.
Many of his arguments were given added credibility last week by the European Environment Agency's annual report, which pointed out just how much things were improving across the continent.
In 1997, the WWF's international president Claude Martin made a desperate plea: 'I implore the leaders of the world to pledge to save their remaining forests now - at the eleventh hour for the world's forests.' The Worldwatch Institute claims that 'deforestation has been accelerating over the last 30 years'.
But Lomborg says that is simply rubbish. Since the dawn of agriculture the world has lost about 20 per cent of its forest cover, but in recent decades depletion has come to a halt. According to UN figures, the area of forests has remained almost steady, at about 30 per cent of total land area, since the Second World War. Temperate forests in developing countries such as the US, UK and Canada have actually been expanding over the past 40 years.
Britain has more forest now than 200 years ago, and the growth is all broadleaf natural woodlands, not pine plantations. Tropical forests in developing countries are being cut down or burnt, but at a slow rate; and despite all the dire warnings the Amazon rainforest has only shrunk by about 15 per cent. Lomborg concludes: 'Basically, our forests are not under threat.'
Nor are all our species dying out. In the 1979 book The Sinking Ark , campaigner Norman Myers claimed that each year 40,000 species were being made extinct. Others have suggested a figure of 250,000, and claimed that 50 per cent of all species will have died out within 50 years.
But Lomborg cites other studies that show only 0.08 per cent of species are dying out each year. The IUCN - the world conservation union that officially recognises which species are endangered - said recently that 'actual extinctions remain low'.
Conservation efforts have been spectacularly successful. Whales are no longer threatened with extinction, elephants are being culled because their numbers are so high, and the bald eagle is off the endangered list. Never has so much of the habitat of the developed world been protected - the number of officially protected areas in Europe has risen from a handful 20 years ago to more than 2,000 now.
But the most dramatic improvements are elimination of most of the main forms of pollution. Cleaner fuels and clampdowns on emissions mean the last time sulphur dioxide emissions in London were so low was in the sixteenth century. Getting rid of lead from petrol means that in the US lead concentrations in the air have dropped 97 per cent.
The same is true of almost all other main forms of pollution, including soot, ozone, nitrous oxide and carbon monoxide. According to Lomborg: 'Air pollution is not a new phenomenon that has been getting worse and worse, but an old phenomenon that has been getting better and better, leaving London cleaner than it has been since the Middle Ages.'
The oceans have also been getting cleaner. According to the European Environment Agency, in seas around Europe in the past 10 years the amount of cadmium, mercury and lindane has fallen by around 80 per cent.
Many environmental scares have simply failed to happen. Despite repeated fears about a looming 'energy gap', the world now has more energy than ever. In 1980, it was predicted we only had 30 years of oil left but, 20 years on, we know we have at least 40 years left. Improvements in exploration techniques mean the known oil reserves are at record levels.
In the Eighties, there was alarm that acid rain would destroy Europe's forests. Ten years later the fears had evaporated: studies showed acid rain rarely affected trees. It did, however, affect life in lakes, and emissions of acid-making gases were curbed.
'Acid rain does not kill the forests, and the air and water around us are becoming less and less polluted,' says Lomborg. The UN said in 1997 that 'the widespread death of European forests due to air pollution which was predicted by many in the Eighties did not occur.'
'Mankind's lot has improved in terms of practically every measurable indicator,' concludes Lomborg. A recent study by the right-wing Institute of Economic Affairs backed the claim. It produced indicators for most forms of environmental damage and concluded: 'Contrary to public opinion, in most instances, objectives for protecting human health and the environment are being met.'
Environmental groups claim, with justification, that many of the improvements are the results of the success of their campaigns. Stephen Tindale, executive director of Greenpeace UK, said: 'There are important examples, such as acid rain and ozone, where things weren't as bad as predicted, and that's because behaviour changed.
'The ozone layer is beginning to recover because ozone depleters are being very rapidly phased out. It's a tri umph of the environmental movement.' Charles Secrett, director of Friends of the Earth UK, insisted that the environment was facing new threats: 'The more obvious and simple environmental issues have by and large been tackled. But we have replaced smelly pollutants you can see with invisible, sneaky pollutants that affect you over the long term.'
But this change of emphasis comes under heavy fire. Patrick Moore, one of the co-founders of Greenpeace who fell out with the organisation over its radical tactics, said that having been victorious in its early battles the environmental movementhad invented new ones.
He said: 'At the beginning, the environmental movement had reason to say that the end of the world is nigh, but most of the really serious problems have been dealt with. Now it's almost as though the environmental movement has to invent doom and gloom scenarios.'
Environmentalists admit that there has been a change in emphasis - from problems that have actually occurred to warnings about those that might, such as genetically modified foods. 'It is not scare-mongering to draw attention to a risk that could have very serious consequences if it comes to pass,' said Tindale.
Indeed, some potential risks - such as climate change - end up becoming reality if nothing is done. Secrett said: 'Very few environmental groups are doom and gloom merchants. What we say is based on science.'
Critics such as Moore claim that environmental groups have a vested interest in exaggerating problems, because alarming people helps to raise funds. But Lomborg warns it can have serious consequences: 'It makes us scared and it makes us more likely to spend our resources and attention solving phantom problems while ignoring real and pressing, possibly non-environmental, issues.'
anthony.browne at observer.co.uk