UNDER THE MICROSCOPE:A FUNDAMENTAL CHARACTERISTIC of science is that everything is revisable in the light of new persuasive evidence. However, new evidence that contradicts established theories is not always welcomed by the scientists who support these theories. I will discuss this briefly in the context of the theory of evolution and of the current majority scientific position on climate change.
First of all let me say that I accept the theory of evolution through natural selection and I have no time for “evidence” drummed up by people who are motivated to defeat the theory because they perceive it to contradict religious teachings. But, otherwise, the theory of evolution is no more deserving of shelter from genuine criticism than is, for example, the theory of relativity or quantum theory. Nevertheless, there is a feeling abroad in biology that you must not question evolution.
The Chinese paleontologist Jun-Yuan Chen encountered this attitude when lecturing in the US in 1999. He was describing strange fossils in China that led him to question orthodox evolutionary proposals. His questioning was greeted with silence and when he inquired what was wrong he was told that scientists in America don’t like criticism of evolution. He replied: “In China we can criticise Darwin but not the government, in America you can criticise the government but not Darwin.” All science benefits from being responsibly questioned, and this is one of the most important ways in which science grows. Antipathy towards genuine new evidence that runs contrary to established theory is profoundly unscientific.
Another position, far short of qualifying as a scientific theory but supported by the scientific establishment, is the explanation of current global warming. There is a scientific consensus that the world is gradually warming and the majority of scientists believe that this warming is caused by man-made emissions of greenhouse gases, principally carbon dioxide.
However, a not-insignificant minority of scientists disagree and believe that the current warming phase is caused largely by other factors, for example changes in solar activity. I am not expert enough in meteorology and climatology to critically adjudicate on this matter and, so, I accept the conclusions of the majority of experts in this area.
However, I strongly believe that we must listen thoughtfully to the minority of independent experts who advance contrary evidence. Several of these experts, such as the noted physicist John Freeman Dyson, have repeatedly warned that the modelling systems used by the International Panel on Climate Change (IPCC) are not nearly as effective as the IPCC claims. Most recently, Lenny Smith repeats this warning in New Scientist(December 6th, 2008). Smith is professor of statistics at the London School of Economics, and won the Royal Meteorological Society's Fitzroy Prize for applied meteorology in 2003.
He accepts that man-made climate change is real but warns that the IPCC climate modellers are overselling their results. Smith says the models give us some idea of what might plausibly happen but they cannot predict the details. Nonetheless, modellers are predicting details and are very shy about admitting to uncertainty. There is a significant chance that something entirely unexpected may develop with our climate and if that happens science will be brought into disrepute.
A strong climate-change lobby supports the majority scientific opinion and brooks no criticism whatsoever. I recently wrote a column reporting some criticisms of the IPCC position. My purpose was simply to outline these criticisms, not to support them, and I made this clear. I was roundly criticised by the climate-change lobby. I was accused of pursuing a personal agenda and of being unscientific, although the details of the arguments I described were not addressed. The reaction was similar to what I might
have attracted back in 1940s Ireland had I reported something critical of the Catholic Church.
Apparently, a scientist criticises the IPCC position at his or her peril. Readers will remember Dr David Bellamy, respected botanist, author of 35 books and presenter of about 400 television nature programmes – a very effective and popular ambassador of science to the general public. Bellamy has been missing from our TV screens for the past 10 years. He claims that he is being shunned by the BBC and by fellow scientists and environmentalists because he doesn’t believe that global warming is man-made. He likens the reaction he has received to McCarthyism.
All Bellamy’s arguments about global warming are, to my knowledge, based on scientific data. He may well be misinterpreting this data, but a confident scientific mainstream should have the technical ammunition to clearly demonstrate this in public debate with him.
If he is being shunned, this is very worrying. Surely his long, successful record in popular science should have earned him enough credit to merit more respectful treatment from his colleagues.
William Reville is associate professor of biochemistry and public awareness of science officer at UCC – http://understandingscience.ucc.ie
