“Climate deniers are mad”

The Guardian (God bless it) of Sept 23^rd carries a wonderfully patronising article seeking to analyse the psychological traits that lead to “climate denial”.  You might paraphrase it “Why climate deniers are mad”.

Note the implied assumption that the current climate orthodoxy is “settled”, that all sensible people accept it, and that dissent is not seen as a sign of keen interest and lively debate, but simply evidence of flawed psychology verging on madness.  This shows a fundamental failure to understand the scientific method.  Anyone (like President Obama) who asserts that “the science is settled” just doesn’t understand science.  Science is about establishing hypotheses which are always subject to potential falsification by subsequent data or experiment – indeed if a proposition is not falsifiable, it is not science.

Author Michael Crichton (Jurassic Park) expressed it perfectly: “There is no such thing as consensus science.  If it’s consensus, it isn’t science.  If it’s science, it isn’t consensus.  Period”.  Yet the Guardian is still repeating the “97% consensus” myth which has been comprehensively debunked.  And it reports that “Rejection of experts spreads from Brexit to climate change” – despite the fact that the “experts” proved diametrically wrong on Brexit.  Be careful what similes you choose – they may come back to bite you.

The suggestion is that “climate deniers reject climate science”.  Yet for a start, there are no climate deniers.  No one denies that the climate exists. No one denies that it changes.  But there are different interpretations of the reasons driving the changes in climate.

Secondly, I’m not aware of anyone who rejects the science.  But we (clearly I am someone whom the Guardian regards as a “climate denier”) do reject dogmatic interpretations of the science that lead to improbable conclusions.

No one denies that CO₂ is a greenhouse gas.  But we do question the dogmatic assumption that the world’s complex and chaotic climate system can be reduced to a single variable.  Even the IPCC identifies many factors that impact on the global climate (like solar changes and volcanoes), before deciding that perhaps CO₂ is the only one that merits its attention.

We “deniers” note that the world’s average temperature has followed a 1000-year cyclical pattern for at least 10,000 years, and arguably for much longer.  We note that the slight late-twentieth century warming is entirely consistent with that long-term, natural cyclical pattern, and therefore (applying Occam’s Razor) we are disinclined to seek exceptional explanations for it, or to pin the blame on anthropogenic CO₂ emissions.

We note also that the standard IPCC position involves large numbers of computer models of global temperature which have persistently and grossly over-estimated future temperatures – failing the basic test of science that hypotheses should lead to predictions which can be confirmed experimentally.

We recall Al Gore’s film “An Inconvenient Truth” in which he cites a long-term (600,000 year) correlation between temperature and atmospheric CO₂ as conclusive proof that (unexplained) changes in CO₂ levels drive temperatures.  We on the other hand note that the temperature cycle precedes the CO₂ cycle by a thousand years or so, and we conclude that the temperature drives the CO₂ level.  It seems likely that the long-term temperature cycle is driven by cyclical astronomical factors.  And we know that warming oceans are able to hold less CO₂ in solution, so warming results in CO₂ being released from the oceans into the atmosphere.  There is approximately fifty times more CO₂ in the oceans than in the atmosphere, so relatively small changes in dissolved CO₂ in the oceans can result in disproportionate changes in atmospheric CO₂.

Warmists cheerfully assume that rising CO₂ levels over the last century are solely the result of anthropogenic emissions.  They could equally be the result of cyclical warming and out-gassing from the oceans.

We recall that in geo-historical terms, the current level of atmospheric CO₂ at around 400 ppm is very low – the level has been at least ten times higher, maybe fifteen times, in the remote past, and those periods were not associated with “runaway global warming”.  We recall also that CO₂ is an invisible, non-toxic trace gas in the atmosphere, a gas which is essential for life on earth.  In fact the current increase in atmospheric CO₂ is greening the planet, promoting plant growth, bio-mass formation and crop yields.

We “deniers” even know enough about climate science to be aware that the warming effect of atmospheric CO₂ is non-linear —  it follows a law of diminishing returns.  It takes a doubling of CO₂ to produce a given temperature impact.  So if doubling from say 400 ppm to 800 ppm produced a temperature rise of x^oC, it would take not another 400ppm, but another doubling – 800 ppm – to produce the next x^oC.

So this begs the important question – what is the value of “x”?  Surely the orthodox climate scientists and the IPCC must know the answer?  Right?  No.  Wrong, I’m afraid.  The IPCC offers a range of estimates from 1.5^oC to 4.5^oC – an enormous variation.  A factor of three.  Some climate scientists believe that the actual value may be even lower, and the gross over-estimates of computer-based temperature projections lend credence to that view.

It is simply absurd that the Paris Climate Conference proposes “a limit of 2^oC on global warming”, and argues between 2^o and 1.5^o, when the official climate science body, the IPCC, offers such a huge range of uncertainty on climate sensitivity.  Its forecasts become virtually meaningless.

Add to this the effect of both positive and negative feed-back effects, which are not at all well-understood, and the uncertainty becomes overwhelming.  Some climate scientists believe that the net effect of all feedbacks could be negative.  I personally lean to the view of distinguished American atmospheric physicist Fred Singer that “if there is a signal from anthropogenic CO₂ emissions, it is lost in the noise of other factors”.

So the world is not divided between rational climate scientists who subscribe to the IPCC consensus, set against anti-science “deniers”.  On the contrary, there is (or needs to be) a real debate between different but legitimate opinions and interpretations about the conclusions that can be drawn from a very uncertain and complex situation.  Oh, and maybe the Guardian could try to take a slightly less patronising tone.