The Club of Rome published in 1972 a book called The Limits to Growth, which gained a huge success. The book predicted, based on computer calculations, how the population growth, industrialisation, the increase in food production and pollution are going to expand in such an increasing volume that a total collapse is expected in only a hundred years' time.
Using a technique known as systems dynamics, developed by Professor Jay Forrester at MIT, a large-scale computer model was constructed to simulate likely future outcomes of the world economy. The most prominent feature of systems dynamics is the use of feedback loops to explain behaviour. The feedback loop is a closed path that connects an action to its effect on the surrounding conditions which, in turn, can influence further action.
There are two feedback loops, negative and positive, the total outcome of which would create pessimist or optimist models depicted in the book. Using some over-simplified examples here, pollution and damage to the biosphere caused by industry would be a negative feedback loop; on the other hand, the jobs and prosperity created by that same industry would be a positive feedback loop. The different combinations of these feedback loops would have an effect on whether the future developments would be benevolent or not.
The basic message of the Club of Rome in 1972 was that there will be a collapse if the population increase and industry growth go on without any limitations. The turning point was to be in twenty years. Dennis L. Meadows, one of the writers of Limits to Growth, tells that the calculations of 1972 were just checked for the third edition of the book, and that the predictions had become true within the accuracy of a few per cent units.
Dennis L. Meadows says that the limits were exceeded in 1980; now we are twenty per cent above those limits, and have to turn back. According to Meadows the modern world differs from the state of sustained development as much as the ancient Mesopotamia would differ from the world of industrial era.
During its recent summit in Helsinki the Club of Rome didn't speak about the limits to growth any more but the "limits of ignorance". Their concern is that the risks are well known, but in spite of that, no changes are put through. (One recent example of this would be USA's reluctance to accept the proposed Kyoto Protocol.)
The real problem here is that almost religion-like current economic thinking, which emphasizes the idea of ongoing and continuing growth. Unfortunately, it only seems that this growth can be gained at the expense of natural resources and people's mental well-being. We can't buy happiness.
More info @ DieOff.Org
Fair Warning? The Club of Rome Revisited
Beyond The Limits To Growth