UNDER TEH MICROSCOPE:The green movement can't claim to base its views on science and then reject established positions, Dr William Reville.
MY COLUMN of June 26th, criticising aspects of green philosophy, created a bit of a stir. Most personal correspondence I received was supportive but I was disappointed with the green criticism, much of which accused me of being "unscientific" or of using "half-truths". Other green reactions ignored my arguments and simply expressed outrage that I expressed criticism. In this article I hope to demonstrate that nothing I said was unscientific or untrue.
Several commentators claimed I made unscientific comments about world population, use of DDT to combat malaria, and the nutritional parity of organic versus conventional food. First, world population. I said that "birth rates are plummeting" globally. Several commentators interpreted this as "world population numbers are plummeting", which I didn't say. The rate of world population growth has been in continuous decline since the 1980s. In 2005, the average woman in the developing world had an average 2.9 children, down from an average of nearly six in the 1970s. In some less developed countries, fertility is at or below replacement levels. World population numbers continue to rise, but rate of increase is in decline. This is fact.
I said that the low-level use of DDT to combat malaria "poses no health hazards". My reason for saying this is the research summarised in a review article by AG Smith ( The Lancet, Vol. 356, pp 267-268, 2000). Such research convinced the World Health Organisation, which gave the indoor use of DDT a clean bill of health for controlling malaria in 2006. Dr Anarfi Asamoa-Baah, World Health Organisation assistant director general for Aids, TB and malaria said, "The scientific evidence clearly supports this reassessment - DDT presents no health risk when used properly".
Another commentator took exception to my claim that organic food was no better nutritionally than conventional food. He referred to dosing factory-farmed animals with antibiotics and using pesticides in plant production. He claims that these chemicals end up in the consumers of these foods. But this will not happen to any significant extent if the official rules are followed. Thus, the levels of antibiotic that can be administered, and the withdrawal period before slaughter, should ensure the safety of the consumer. Also vegetables should be thoroughly washed before use to remove residual pesticide. Risk may result if the rules aren't followed, just as you risk ingesting harmful faecal micro-organisms from organic vegetables if you don't wash them thoroughly before use.
Now to somewhat more complicated matters. I said, "the green movement believes in a goddess called Gaia". Gaia, a Greek goddess, is the name given by James Lovelock to his hypothesis that the Earth, together with life on Earth, form a single system of complex feedbacks that regulates the Earth so that it remains hospitable for life. I never met a green who didn't accept the Gaia hypothesis. I myself think the Gaia hypothesis is a very creative concept.
However, I am not stupid enough to think that more than a tiny minority of greens literally believe that Gaia is the Earth goddess who knowingly rewards us for being friendly to the environment and punishes us for polluting. But, it seems to me that some greens' attitudes are coloured by this and some seem to believe that humans are weeds in the garden of life. In the words of Mikhail Gorbachev, "Nature is my God. To me nature is sacred; trees are my temples and forests my cathedrals".
I said that the golden rule of the green is to "live sustainably". Some critics concluded that I don't agree with sustainable development. Of course I agree with sustainable development. However, I don't agree with every green recipe for sustainable living.
The green movement is very broad, and broad enough to include me. In general, it simply means taking care not to degrade the environment. It would be insane to disagree with this. I accept that modern industrial/ technological activities press dangerously on the environment. I agree that we must take care to monitor this, to take action to remediate damage, and to make sure we are developing in a sustainable manner.
Green philosophy claims to be guided by science but in practice greens pick from the à-la-carte science menu. This is readily apparent when one considers green scepticism on, or opposition to, the following selection of positions advocated by mainline science: expansion of nuclear power to minimise emissions of greenhouse gases; cautious introduction of certain genetically modified crops; public water fluoridation; classification of homeopathy as pseudoscience; incineration as part of overall waste management; widespread medical immunisation, etc.
The greens have done very useful work in squarely putting the environment on the political agenda, but if we are to make real progress, all our actions in this area must be guided by science.
• William Reville is associate professor of biochemistry and public awareness of science officer at UCC - understandingscience.ucc.ie.