My experience with Greenpeace gave me a long-running interest in the way much environmental science involves mathematical formulas or computer models. The most famous recent examples of these are the "general circulation models" used to produce predictions of future climatic conditions. An important book has just been published by an Australian academic that raises the question of whether this should be regarded as science at all.

The book is Science And Public Policy, and the author is Professor Aynsley Kellow, the head of the school of government at the University of Tasmania. Kellow believes that environmental science has often been corrupted by the good intentions of its practitioners, so that it consists of wishful thinking rather than facts and provable theories. Perhaps the first big case of this was the notorious Limits To Growth study published by the Club of Rome in 1972, based on computer modelling and subsequently disproved. One might expect the quality of models to improve, but since then they have been used for all sorts of predictions, and there is little evidence they have got much better.

Despite this, the predictions made by such models are now contained in scientific papers published in leading journals, which gives the status of science to what is often little more than wishful thinking.