Saturday, 9 January 2010

Book Review: Ian Plimer, "Heaven and Earth – global warming: the missing science"

I wish I could recommend this book, I really do. After all a book which gives an overview of climate change from the creation of the Earth up to the present, which cites 2311 (mainly peer reviewed) references and runs to over 500 pages can’t be all bad. Can it?

Ian Plimer is both a distinguished geology professor and practicing geologist. As such he takes a long-term view of climate (billions of years not just decades or centuries). During this period earth has undergone changes to climate which make the changes recorded during historical time seem puny by comparison. His background also leads him to consider, and give more weight to, ‘geological’ forcing of climate change such as submarine vents.

The ‘meat’ of the book comes in five chapters headed “The Sun”, “Earth”, “Ice”, “Water” and “Air”. In the “Sun” chapter he argues that the sun as the sole source of external energy is the main driver of climate on earth and that the the interaction of the solar wind with cosmic rays is an important mechanism for climate change. The “earth” chapter covers volcanoes and Milankovitch cycles. He argues that that glaciers and sea ice have always advanced and retreated and that current changes are not unusual. He also discusses the physics of water and the influence some its properties (like the fact that ice floats on water) have on climate. In the “Air” chapter he examines the accuracy of temperature and CO2 measurement. Throughout the book he adopts an undeniably sceptical point view with regard to climate change. That said, he also appears to agree with some of the ‘consensus’ view. For example after saying that water vapour is the main greenhouse gas he continues “When times are warmer, water vapour evaporates more readily.” Later he also writes “Water vapour is an amplifier not a trigger.” He also concedes that “some of the increase in atmospheric CO2 measured over the last 150 years is of human origin.”

I learnt much from this book and many of the questions he raises are valid. For example he quotes from a number of studies which suggest that the residence time of CO2 in the atmosphere is around 5 years, much less that 50 to 200 years assumed by the IPCC.

So why don’t I feel able to recommend it? Well the answer, indirectly, comes from the author himself. In his introduction he says “Hypotheses are invalidated by just one item of contrary evidence, no matter how much confirming evidence is present.” The same could be set of a technical book. If it has errors then the reader cannot rely on it. That, unfortunately is the case with this book.
He says, for example, with reference to devastation of Hurricane Katrina, “The whole of the Texas Gulf area is subsiding. In the three years before the flood ... the city and the surrounding area had undergone rapid subsistence of about one metre.“ He gives no reference for this but later in the book cites a Nature paper (Dixon et al, 2006) which quotes a maximum rate of 28.6 mm/year but that is only at a few isolated spots in New Orleans and its surrounds. In other places nearby the subsidence is much less. He also claims that volcanoes produce more CO2 than fossil fuel burning whereas it is generally accepted than the ratio is 30 to 1 in opposite direction.

The author will often scrupulously cite references for relatively minor statements and then make sweeping statements without any source. In a rather confusing section, where mixes percent and absolute values, he says that 186 billion tons of CO2 enters the atmosphere of which 3.3% [equivalent to 6 billion tons, the accepted figure is 5 times higher] comes from human sources and ... 71 billion tons is exhaled by animals (including humans). This could do with a reference. Later in the same paragraph he says that Global warming did not cause the mass extinction in 65 Ma, and does give a reference.
In a similar way the author has a lot of graphs none of which are referenced and a least one of which is wrongly labelled. In the introduction he admits that they were “fly scratchings” which someone else converted into line diagrams for him so that lack of references is not surprising.

The book could also do with a good editor. Statements like “The winter of 1815-1816 was known as ‘the year without a summer’” should not have been allowed to stand. There are also numerous unnecessary repetitions. For example in one place he writes “...rebound is occurring in Scandinavia, Scotland and Canada after ice sheets up to 5 km thick melted over the last 14,000 years”. Two pages later we read “ sheets started to melt 14,700 years ago, and Scandinavia, Scotland and North America are currently rising...”.

The book was warmly welcomed by sceptics and attacked by warmists. There is indeed a lot of ammunition for sceptics but the errors and other shortcomings make the book easy prey for those who want to criticise it. If a second edition is published with the defects corrected it will be a useful contribution to the debate on global warming. Unless, and until, this is done I cannot recommend it.


Publisher: Quartet
ISBN: 9780704371668

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