Robyn Williams: Ian Plimer's book Heaven + Earth has been on the bestseller lists for a month. It takes an unusually harsh line on climate change, the received wisdom. This review by Professor Malcolm Walter from the University of NSW.

Malcolm Walter: At the core of Ian Plimer's book are two propositions. First, that scientists like everyone else can be victims of fashion; and second, that it suits the vested interests of some influential nations to promote knowingly a false belief in anthropogenic climate change. He asserts that the fashion is the acceptance of the reality of anthropogenic climate change, so he takes up the challenge of exploding this scientific myth. It seems that for Plimer, this is like his earlier battle with creation science, where he had a moral victory but lost in court. With his usual panache he charges into battle, David against the Goliath of the IPCC, the Intergovernmental Panel on Climate Change, and all its minions and knaves.

Plimer has amassed a vast and impressive array of facts, hypotheses and speculations, all documented with hundreds, in fact thousands, of footnote references and packaged into 503 densely written and sometimes almost unreadable pages. There are long, meandering discourses on irrelevant subjects such as the early evolutionary history of the animals, interspersed with fact-packed pages on the geological and archaeological records of past climate change. There are massive compilations of hugely diverse subjects ranging from the evolution of the universe to the history of grasslands during the Pleistocene glaciations. These compilations demonstrate an enormous amount of work on his part, but many long sections read as little more than lists.

There are blatant and fundamental contradictions. We read on page 165 that 'the proof that carbon dioxide does not drive climate is shown by previous glaciations'. Then on page 169 we read 'If global volcanicity was reduced, then the amount of carbon dioxide entering the atmosphere would have been less and the planet's atmosphere would have cooled'. Either CO 2 concentrations affect climate or they don't. On page 436 Plimer writes of the last century 'There has been a rise in CO 2 , yet cooling is taking place', yet on page 25 he has a graph showing an overall warming trend, with some fluctuations as would be expected in any complex system.

There is fallacious reasoning. Take this statement on page 87: 'If it is acknowledged that there have been rapid large climate changes before industrialisation, then human production of carbon dioxide cannot be the major driver for climate change.' This would only be true if carbon dioxide concentrations were the only driver of climate change, something that no-one proposes, as far as I know. This level of naiveté, if that's what it is, is hard to comprehend. It is true that prior to Homo sapiens walking the Earth there were huge fluctuations in climate, far bigger than any contemplated right now. But it is also true that it is widely accepted that many variables caused or contributed to those changes, carbon dioxide concentrations in the atmosphere being just one of the variables. But ultimately that is irrelevant. The situation now is that on the timescale that matters most to humans; years, generations or centuries; carbon dioxide concentrations are increasing, and that is one of the variables, and probably the major one, driving climate change at present.

The fact that variations in the Earth's orbit, variations in the luminosity of the Sun and many other factors have driven climate change on a geological time scale is cold comfort. We weren't around to be bothered, except for very recent times. And there were no huge cities on coastlines and no complex economies structured around climate-sensitive agriculture. Sure, mankind survived severe glaciations and the intervening warm periods, but we demanded little of our environment then, and as nomads we could migrate easily. Now we occupy a vastly complex system of our own invention, and that system is very sensitive to perturbations, whether they be influenza epidemics, great wars, global financial crises or climate change. We would be irresponsible fools not to attempt to mitigate the effects of these noxious perturbations.

An analogy might be helpful. We unwittingly damaged the atmosphere by releasing chlorofluorocarbons, CFCs, from refrigerators and other sources for decades until 1989. That caused the ozone hole in the southern hemisphere and increased the risk of skin damage and cancer. Once that was recognised, global action was agreed and taken. This shows that even relatively small human actions can seriously perturb the atmosphere.

Plimer has to be admired for attempting to gather together and summarise a vast amount and range of science. It's a daunting task. The book may well be a useful source of references for those who wish to delve deeply into this subject. But my overall impression is that he bit off more than he can chew. There is a mass of only partly digested material and poorly expressed interpretations. Severe editing would have helped keep the message clear and well reasoned, and he was not well served in that regard.

This book matters partly because the public understanding of science is limited. We don't attempt to measure that understanding in Australia, but it has been done in the US and Europe for 50 years or so, where the proportion of people with a fair level of scientific understanding is estimated at 28% in the US and 14% in Europe. The Australian public probably lies somewhere in this range. It seems to be poorly understood that science advances by challenging accepted interpretations and demanding new evidence. Disputes are a normal part of our business. But because of poor understanding of the process of science, healthy disputation can be misinterpreted in the public and by journalists. Contrarians like Plimer can be seen as saints resisting evil, and the IPCC can be portrayed as a giant conspiracy.

I think Plimer is entirely sincere in his efforts to argue against anthropogenic climate change. But he is misguided, and his interpretation of the literature is confused. Why do I have any credibility on this issue? Like Plimer I am a geologist, with a very long experience in basic fieldwork. I have particular experience in working on the evidence for severe glaciations in the past, and on understanding the early history of the Earth. I am also a planetary scientist with an interest in other planets in the solar system, including their climates.

Reviewing this book has been an unpleasant experience for me. I have been a friendly colleague of Plimer's for 25 years or more. I admired his support for innovative geological research during his early career as a mineral explorer in industry. I cheered him on when he took on the so-called creation scientists and their bogus nonsense, a crusade that cost him dearly in the end. I have enjoyed his always lively and entertaining lectures. But this time, in my opinion, he has done a disservice to science and to the community at large.

Robyn Williams: Professor Malcolm Walter from the University of NSW. He was reviewing Ian Plimer's book Heaven + Earth. Another review here next week. And you can hear Kurt Lambeck, the president of the Australian Academy of Science, take a look at it in this week's Ockham's Razor.