Hot Topic

“The Alarmists were right, and we shouldn’t call them alarmists any more – or at least not all of them!” For rather dubious reasons Gareth Morgan and John McCrystal decided to call serious climate scientists Alarmists throughout their book. A retraction on the last page seemed to me rather late. But the appellation  suited the tenor of their title: Poles Apart:  Beyond the Shouting, Who’s Right about Climate Change?

(For the benefit of readers not familiar with the New Zealand background, Gareth Morgan is an economist and investment adviser who commissioned scientists, including sceptics, to answer the authors’ questions about climate change. The book reports the findings. Information about some of the papers they commissioned can be found on their website.)

The fancy on which the book proceeds is that there are two unruly groups of scientists, designated Alarmists and Sceptics, much occupied with hurling abuse at each other and consequently confusing the poor general public. But the authors have entered this baffling arena and emerged with a verdict, making suitable admonishments to the scrapping parties along the way.  It’s not a scene I recognise from my three years of reading about the sober work of climate scientists, but it’s the presentation framework chosen by the authors for what proves on the whole to be a genuine engagement with the science of climate change.

It’s the seriousness of that engagement which made their favourable verdict almost inescapable. Their exposition of how global warming is occurring, according to the science, is clear. Their account of the case for anthropogenic global warming covers both the evidence for warming — in the cryosphere, the oceans, the atmosphere and the biosphere — and the evidence that it is due to increased CO₂ from fossil fuels and unable to be explained by any other cause.  The treatment is often quite detailed, and while they always have an eye open to the possibility of  overstatement they don’t actually accuse anyone of it in this section of the book. (Though in an earlier chapter they describe Michael Mann’s so-called hockey stick thesis as a grievous overstatement of the case and accuse the IPCC of conspiring to send a resoundingly false message to the public — a rather grievous overstatement itself.)

They do their best with the case against global warming, but it is apparent they are having difficulty with it. They lean towards Svensmark’s theory of the significance of cosmic rays, finding its graphs carry some conviction but they don’t make a big deal of it. They consider the argument that increased precipitation will decrease the impact of increasing water vapour as a feedback mechanism. Some attention is given to Lindzen’s theory that there is a self-correcting mechanism in high cirrus changes above the tropics, depending on warmth, but they acknowledge that it has not fared well against evidence. In fact this chapter ends with the acknowledgement that the objections to the theory of anthropogenic global warming are weak, but adds they do leave doubts about the IPCC’s numbers, especially the projections of how much warming to expect.

However when the book turns to that question it reaches the conclusion that the result of doubling the CO₂ level in the atmosphere is highly unlikely to lead to anything less than a 2 degree temperature rise and settles for the IPCC’s estimates of a range between 2 and 4.4 degrees. Incidentally at the end of this chapter Bob Carter’s five ‘tests’ against anthropogenic global warming are examined and found seriously wanting. ‘Straw man tests’ they conclude.

Considering their own difficulties in finding substance in sceptical positions it seems unreasonable of them to complain that climate scientists haven’t paid sceptics the attention they deserve.  The authors’ evidence for this seems to be largely anecdotal. They nowhere point to wilful neglect of serious hypotheses. They describe the peer-review process and the difficulty of achieving publication in prestigious journals as if it is open to abuse of power, but don’t venture that accusation themselves.

Cautions about science are always in order, of course, but the authors overstep the mark with comments like these: “The self-assurance with which climatology presently speaks may have more to do with the brash presumption of youth than with wisdom.”  This on the grounds that it is a comparatively recent science. I can’t say that I’ve noticed much self-assurance in what I’ve read of climate science – one often senses almost a reluctance to report what investigations are revealing – but in any case the comparison of climate science with human adolescence is hardly evidence of its inadequacy. It fits the fanciful framework of the book, that’s all.

The arrogance of the IPCC is an overworked theme in the book.  The authors don’t take serious issue with the IPCC findings, but still claim that the aggregate level of certainty in the reports is unwarranted. “It’s as though there has been a general agreement to bring back a verdict before all the evidence has been heard…a conspiracy to overstate the case.” They also accuse the IPCC of not communicating reasonably with the general public. It seems to me that the IPCC bends over backwards not to overstate the case, and if anything errs on the side of caution. And so far as talking to the general public goes, the media’s frequent failure to engage systematically with the subject has made clear communication difficult. However, many illuminating books and articles are readily available to anyone who will take the trouble to read them. I’m no scientist, but I could follow Elizabeth Kolbert and Tim Flannery and James Lovelock (all borrowed from the library at no cost) when I first tried to get a proper handle on climate science three years or so ago, and since then I’ve found no shortage of material available for lay consumption. I don’t know why Morgan and McCrystal weren’t satisfied with such sources, but far be it from me to disparage journeys of discovery, however expensive and whatever the conveyance. They ended up at a fitting destination, and their explanations of why they got there are generally well told and accessible to the general reader.

Their accompanying claims that great uncertainty still surrounds the extent of climate change and its impact are beside the point. All the scientists will acknowledge that there’s a great deal not yet understood. The question is whether there’s enough that is understood to add up to a scientific consensus that we’re in a danger zone.  If there is, then the reservations the authors express hardly measure up against the seriousness of the issue. In a brief concluding comment on policy decisions they advise against using a sledgehammer to crack a nut. (Some likelihood!) When I saw that I wondered whether they have quite realised the consequences of their favourable verdict.

Incidentally on policy matters, the book is incorrect about China and the Kyoto treaty. China ratified it in 2002. Admittedly Kyoto didn’t require them as a developing nation to cut emissions, but they were part of the agreement. The US is the only member to have signed the protocol and then refused to ratify it.