Get Fact: how accurate is Ian Plimer’s new book?
In 1988, Professor Ian Plimer — accomplished geologist, author and company director — debated the theory of evolution with creationist Duane Gish. Gish so exemplified a particular debating strategy, stunning one’s opponent with a disorienting fusillade of factoids, that it became known as the “Gish Gallop”. Since then, Plimer has developed a knack for the Gallop that would leave the (late) master flat-footed.
And so it is with Plimer’s latest book, Not For Greens, to be launched on Monday. The book is a broadside against both the theory of anthropogenic climate change and accompanying arguments for a transition towards renewable energy. In terms of scientific content, little has changed since Plimer’s 2009 climate “sceptic” opus, Heaven and Earth (critiqued here, here, here, here, here, here and here). Plimer did not respond to these critiques, presumably because, in his own words, “Climate ‘scientists’ are certainly green activists but not scientists” (page 44 of Not For Greens). Heaven on Earth sold plenty of copies and can be found on many Coalition MPs’ bookshelves.
Not For Greens nevertheless claims to be scientific. Crikey thought the book was ripe for some scientific fact-checking. Let’s start with Plimer’s questioning of whether the rise in CO2 is human-induced.
Claim (page 26): “If annual total emissions of carbon comprise 33 molecules, only one is from human emissions and the rest is from natural processes.”
In 2012, human activity (fossil fuel combustion, land-clearing and cement production) produced approximately 9.7 gigatonnes (billion tonnes of carbon, or GtC). This is dwarfed by emissions from the terrestrial bioshpere (about 120 GtC) and the oceans (about 80 GtC). That makes human emissions around 1 part in 21. Plimer’s numbers need updating but it isn’t fatal to his point.
The problem is the accounting sleight of hand that follows. In typically uncompromising language (page 26): “… if human emissions drive climate change then it has to be demonstrated that this one molecule in 85,000 drives climate change and that the 32 molecules of carbon dioxide derived from natural processes do not.”
Uncompromising. Wrong. Plimer excludes a salient point. The earth has a carbon cycle. So carbon entering the atmosphere through natural processes cycles back to the biosphere and oceans via natural processes, so net natural emissions are zero (in fact, slightly less, since these reservoirs currently act as a sink for anthropogenic carbon). Thus the rise in CO2 concentration is drive by humans.
For clarity, I have rendered Plimer’s argument in diagram form below.
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