The climate sceptics’ hero, Ian Plimer, has a new book out. Climate academic Ian McHugh fact-checks some of his claims about climate change. And did Plimer plagiarise?
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.
Figure 1: The emissions cycle according to Plimer.
Claim (page 27): “It has yet to be shown that the atmospheric increase in carbon dioxide is due to natural degassing or human emissions of carbon dioxide” and (page 66) “… a very slight change in ocean degassing easily accounts for increases in carbon dioxide.”
Again uncompromising. Again wrong. We know the CO2 composition of the atmosphere over the last 800,000 years from analysis of gas extracted from ice cores. For more than 10,000 years, it remained between 260 and 280 parts per million (ppm). In the late 17th century — around the time of the industrial revolution — it began rising slowly before accelerating through the 20th century. Nature would seem to be astonishingly attuned to the tide of human affairs.
Here’s Plimer’s argument in diagram form below, as done by me.
Figure 2: The Plimer interpretation of recent variations in CO2 concentration.
Plimer’s favoured natural CO2 source is volcanoes. But we also know something of the origins of the carbon from isotopic evidence. CO2derived from organic matter (eg fossil fuels) has a distinct chemical signature, because plants preferentially absorb lighter forms (or isotopes) of carbon when they photosynthesise. The chemical signature for volcanoes is different. We also know that the carbon is old, because it contains almost none of the heaviest carbon isotope, which decays over time.
Further, the US Geological Survey published this article in 2011 with a best estimate of the ratio of human to volcanic CO2 emissions of 130 to 1. Plimer once claimed that human emissions were only 3% of volcanic emissions, but is less explicit here, possibly because of the comprehensive comprehensive debunking he received.
Here’s Plimer’s argument in diagram form.
Figure 3: The Plimer interpretation of anthropogenic versus volcanic CO2 production ratio.
Claim (page 9): “As CO2 is increasing and temperature is not, therefore this gas could not be driving global warming.”
Uncompromising. Wrong. This would only be true if no other factors influenced temperature. But as Plimer emphasises, other factors (primarily ENSO, aerosols and solar variation) are important. Straightforward statistical analysis shows that most of the recent variation in temperature can be explained by these factors — in combination with CO2. Moreover, as Plimer himself states (page 10): “The oceans contain a lot of heat, far more than the atmosphere.” True. Then this (page 10): “The key to climate change is the oceans …”. So — is the ocean warming? Yes. My last diagram (this time without Plimer ‘s input) presents changes in energy content of the atmosphere, ocean, land and ice. The oceans store 90% of the additional energy being retained by earth (as opposed to about 2% into the atmosphere). No sign of a slowdown.
Figure 4: Energy accumulation in earth system components (IPCC WG1 AR5)
The above is a small selection of the many dubious claims made in the book. But this is probably irrelevant. The target audience will buy this book because they select their spokespeople in the same way as Plimer selects his facts: those which are convenient to their interests.
Science aside, much of Plimer’s rambling prose is devoted to insulting his imagined ideological foes, as here (page 4): “Past experience shows that the greens’ response to criticism is to plagiarise and repeat the rantings of others …”
I wouldn’t go so far as to charge plagiarism, but sometimes the echoes ricocheting around in the climate contrarian echo chamber can be of remarkable fidelity. Here’s Deepak Lal in the Business Standard (July 17, 2007):
“Today, the peer reviewed process of funding and validation of scientific research in climatology is equally controlled by the modern equivalent of the Collegium Romanum (the Vatican’s Institute of Research), the Inter-government Panel of Climate Change (IPCC). They in turn answer to the equivalent of the Inquisition, the Green ideologists, who, mercifully, can only torment through derision or denying the heretics research funding, and not the frightening instruments of torture.”
And here’s Plimer in Heaven and Earth (2009, page 463):
“The peer review process in climatology research is controlled by the Collegium Romanum, the IPCC. They in turn are answerable to the Inquisition, the global warming fundamentalists, who in today’s world cannot yet resort to torture.”