It?s exactly the sort of document that an American think-tank would have produced in the year 1900, if they had think-tanks in 1900. This time it?s the Chinese Academy of Sciences, and the document is called China Modernization Report 2006.

That imaginary American think-tank of a century ago would certainly have predicted massive urbanization and far higher incomes in the United States of America by 1950, because those trends were already well established at the time. It might not have forecast that half the American population would own automobiles by 1950, let alone that tens of millions of Americans could afford to travel abroad by then, but a bold forecaster might have done so. And when it all came true, nothing terrible happened as a result.

This time the predictions won?t come true, because terrible things will start to happen long before 2050. This is deeply unfair, because all China wants for its citizens is the same lifestyle that most Western countries had achieved by 1950. But they got away with it because they were the first countries to industrialize, and China won?t because it is so big and because it has come so late to the game.

The report, published on February 9, glows with enthusiasm for the predicted rise in Chinese incomes (tenfold by 2050, to $1300 a month), for the 500 million peasants who will move to the cities, for the 600 million city-dwellers who will move out into hi-tech suburban homes. Half China?s people are predicted to own cars and be able to afford overseas travel. But I don?t think so.

At the beginning of World War II, the world had two billion people, of whom about one quarter lived in industrialized countries ? but few of them owned cars, or air-conditioners, or travelled abroad. Forty years later there were four billion people. Those who lived in fully industrialized societies by now consumed far more energy and produced far more waste, as a ?modern? lifestyle included cars, meat in most meals, electrical appliances galore and, for many, foreign travel, but they were still only a quarter of the population. Total human pressure on the environment? Up fivefold or sixfold in forty years.

Fantasy report

Now we have six and a half billion people, and we are still running at a quarter of the human race living in developed countries, so the pressure on the environment is around ten times what it was in 1940. But the predicted development of China by 2050 (and that of India, Brazil and Russia) will raise the share of the human race living in high-consumption industrial economies to over half of the global population ? which will exceed eight billion by that time. Total human pressure on the environment: perhaps 25 times higher in a single century.

It?s China?s turn, and it?s monstrously unfair that it cannot just follow the same development path that Britain first carved in the late 1800s, and all the rest of the West followed in the1900s. But it can?t. You cannot get away with that style of development any more when the world is already as damaged as it is now.

James Lovelock?s new book, Revenge of Gaia, shows what proportion of the Earth?s surface would remain suitable for agriculture if the average global temperature went up by 5 degrees celsius. None of China is habitable except Manchuria. None of India makes it either, except the foothills of the Himalayas, and none of the US except the Pacific north-west.

So the China Modernisation Report 2006 is just a fantasy. The day will never arrive when half of China?s population owns cars. On the other hand, the day must arrive when China?s people (and India?s and Brazil?s and Indonesia?s) will live as well as Americans, or else there will be hell to pay. So the day may well arrive when more than half of all Americans don?t own cars either. The future, as usual, is not going to be like the present.