Friends and enemies of the earth

Jonathon Porritt is a fundamental environmentalist, Greenpeace being the organisation most closely allied to his views. He claims that modern science is not in a fit state, either philosophically or methodologically, to enable it to meet the challenge of sustainability.

None of these terms, including "'sustainability" or "science" itself, is properly analysed in this volume. Virtually no solutions are offered other than a return to a sense of the sacred, and the example of Swedish legislation on environmental pollutants. The book is an example of anti-science by someone who has little understanding of science but appears to be happy to use it when it suits his political purpose. There is also, just hidden, a religious underpinning.

Porritt starts with the already tired proclamation, for which the evidence is poor, that the public no longer trusts or respects science. But he does acknowledge, albeit very briefly, that it is evidence from scientists that has forced politicians to address what he sees as an environmental crisis. However, unlike his allies, scientists are arrogant and lack humility or wisdom; for many scientists the pursuit of truth has become an academic self-indulgence and they exploit genuine uncertainty to cause doubt by allusion. Many have sold out. Little or nothing is produced to justify this, though Steve Jones, Richard Dawkins and myself are used as models of arrogance and evil reductionism; yet none of us has either power, influence or expertise in relation to the environment.

Porritt sneers - there are lots in the book - at the idea that reliable scientific knowledge is value-free, a suggestion at which "many people just fall about laughing. As is now widely recognised, science is 'socially constructed' by all sorts of rules, peer group pressures, values and expectations." That is the level of his analysis. He refuses to accept the distinction between scientific knowledge and its applications, and to recognise that when it comes to applications scientists are rarely in charge as they do not control the funding - money and economic issues are rarely mentioned by Porritt. He is cautiously enthusiastic about the "precautionary principle" and claims many scientists have challenged its scientific validity. One must ask who these scientists are, and also state that the precautionary principle is not a scientific principle - more like a political principle.

The ministry of agriculture comes in for particular blame in its failure to defend farmers from organophosphates that have damaged their health, and pesticides that are doing terrible damage to everyone (no problem here with the scientific evidence). Cancer incidence in the US is said to have doubled between 1950 and 1991 and the editor of The Ecologist is used as authority to claim that everyone knows that the causes of cancer are environmental carcinogens and ionising radiation from medical X-rays, nuclear tests and nuclear installations. The reality is that death rates for cancer - a much more reliable indicator than incidence - are falling in this country and that natural ionising radiation accounts for about 5 per cent of all cancers. There is no evidence for man-made chemicals being responsible for a significant number of cancers.

Porritt quotes with approval hostility to studying breast cancer genes on the grounds that such studies are less interested in finding a cure than in generating research funds. He then quotes geneticist Mae-Wan Ho to illuminate how misguided geneticists generally are. But her claims are misleading: no modern geneticist believes "genes determine characters in linear causal chain" or that they are "not subject to environmental influence". Genetic modification of foods comes in for the same old criticisms the media promoted. The idea that it could help with a world food shortage is dismissed, as (apparently) is the Green revolution of the 1960s and 1970s with its "huge social and environmental costs" - none of which is specified. Yet the book has an almost totally inward-looking British orientation, as if other countries are irrelevant.

Nowhere does Porritt show that he has much idea of the true nature of science and its varied methods. The discussion of thermodynamics is embarrassing: "every atom in the universe today has been part of the universe since the big bang" - a statement which appears to suggest he has no scientific understanding of radioactive decay nor of its being the cause of ionising radiation. He attacks reductionism but seems to have hardly any understanding of how it relates one level of organisation to another. Scientists are aware how difficult it is to reduce, for example, chemistry to physics, but they do know that nothing at one level must contradict the laws at a lower level. There is nothing sinister about reductionism, unless one cannot accept that every aspect of life and non-life in the universe is governed by the same set of universal laws of physics.

The attacks on large industries and science continue throughout the book and the emphasis on sustainability permeates almost every page. But look more carefully and ask what actual practical suggestions to achieve his heroic and very morally justified plans does the author put forward? You will look largely in vain. Should science departments be shut down and research grants withdrawn? One might expect a demand that the chemical industry close down, or if not the whole industry with its polluting chemicals, then at least Frankenstein monsters, like Monsanto. Whose work does he want to stop and where will they find new jobs? Where are the plans for the sustainability he is so passionate about? Engineers and engineering are not even mentioned, yet their involvement is essential.

There is also the delicious irony that when science gives Porritt a result he likes, as in the case of global warming, then suddenly there is a change in tone and a switch to "We know that...". Who is this new "we"? The selection of environmental topics he supports is nearly always in line with what he no doubt thinks the public and associated organisations will support. Motor cars kill and maim a quarter of a million people a year in this country but this is apparently not relevant to an environmental fundamentalist - the consequences would be too inconvenient.

By "sustainability" Porritt apparently means that "our activities would not be dependent on the use of fossil fuels or minerals which exceeded the earth's natural capacity, we would be producing chemical com£ or synthetic materials in a quantity not deleterious to natural systems... and our wealth-creating processes would not result in the net depletion of Nature's life-giving and order-restoring resources". What wonderful high moral ground to stand on - I cannot imagine any sane person, even a scientist like myself, disagreeing. But what does one actually do about it? Should oil extraction from the earth be stopped? In the end he sees the crisis not as an ecological crisis but as a crisis in the way we think: we need instead to think of ourselves and the living world in terms of the sacred.

A possible aim of this book is to make scientists more sympathetic to Porritt's fundamental environmentalism, but the effect is likely to be just the opposite; it will probably completely alienate them. No wonder Prince Charles is so poorly advised. Pity too, the poor environment that so badly needs rational analysis, hard science and positive action - not moral masturbation.

Lewis Wolpert is professor of biology as applied to medicine, University College London, and author of The Unnatural Nature of Science .