Sceptical by Degrees

by Dave Unwin (Chair, SayNoToHarringtonWindFarm group)

The Issue

The major justification for the state-driven push towards renewable energy sources such as wind has been the notion of climate change caused by excess carbon dioxide in the atmosphere as a result of the combustion of fossil fuels such as coal and oil since the industrial revolution.  Computer models of the atmosphere suggest that increasing carbon dioxide will lead, by way of enhancement of the natural greenhouse effect of the atmosphere, to a warmer planet and there is decent observational evidence of warming in two phases during the twentieth century so at first sight it seems that the idea can be confirmed. The shorthand name global warming has been coined as a catch-all phrase to describe it.

Global warming has been enthusiastically taken up by some atmospheric scientists, most ‘greens’, and many politicians, with any dissent rigorously sought out and often subject to ridicule by people like the chairs of the supposedly unbiased Intergovernmental Panel on Climate Change (IPCC), environmentalists, and politicians such as Al Gore in his Inconvenient Truth movie.  More seriously for the countryside of UK, the same hypothesis is being used by company after company anxious to access the massive and unbalanced government subsidies that are on offer to the wind energy industry.  Let there be no doubt about it, if even a small proportion of these schemes go through, the windmills they build will scar the landscape for many, many years to come and, as I hope to show, all on the back of a long chain of suppositions and assumptions that are hard to sustain.

Who’s talking?

Let me say where I am coming from.  Unlike many of those mentioned above, I do not claim special expertise in the specific science of global warming and, until I found it being used to justify over a hundred windmills in a very small area of England close to my home, I tried hard to stay out of any public debate.  My degrees are in Geography, but I taught Meteorology and Climatology at degree level for almost forty years, from 1967 onwards.  On the way in 1965 I was winner of the University of London’s Dora Belasco Medal for Meteorology and Climatology, became a Fellow of the Royal Meteorological Society and even a founder committee member of what is now their specialist climatology research group (originally the Association of British Climatologists).  In those days,  climatology was distinctly unfashionable in our universities, but that was before big science moved in on the back of the global warming hypothesis.  What I have done is to publish a bit in a related field, on observational and modelling studies of how cities modify their outdoor climate.  I’ve also taught a module on climate change for many years and am reasonably familiar, not only with the contemporary literature, but also with a lot of the scientific literature that has led to it.  In short, I’ve been around academically for a fair length of time, from when climatology was the preserve of scholars such as Gordon Manley and Hubert Lamb and even the reality of short period climate change was questioned, to today’s hi-tech approaches in which computer models and satellite remote sensing are the main investigative tools.

Everything in this experience makes me a greenhouse sceptic.  Having ‘come out’ in this way, it’s important to point out that I have never benefited either academically or financially from being sceptical.  Some years ago, the Guardian published a three-line letter from me in which I noted that people like me, climate scientists sceptical about the global warming hypothesis (let’s call this GWH), are not as many environmentalists assert, both mad and bad, and there are perfectly reasonable arguments for taking a sceptical view.  To my amazement this led to my being blacklisted on a ‘green’ website (http://risingtide.org.uk/hallofshame) as a scientist who has ‘done well’ out of being sceptical. That the great cosmologist Fred Hoyle is on the same list is no comfort, quite flattering in fact, but these well-meaning greens are simply wrong.  The reverse is almost certainly the case:  the GWH lobby has done far better out of it than the sceptics and anyhow the supposed scientific consensus is nowhere near as solid as GWH supporters try to fool you into thinking.  Demonizing sceptics shouldn’t belong to science, nor should attempts to censure alternative views as in the utterly disgraceful attempt by two senior members of the warming lobby over the unfortunately named, but entirely justifiable, Channel 4 programme on the Great Global Warming Swindle.

The point I want to make is that there are degrees of scepticism and the entire global warming hypothesis rests on a series of contestable assumptions that are only seldom spelled out.  Let’s work our way through a series of increasingly difficult-to-accept-propositions, starting with:

Proposition 1: Climate changes  

Since the 18th century we have known that the global climate system has experienced huge shifts notably rapidly during the last 2m years or so in the great ice ages.  I doubt that anyone, sceptic or no, is a ‘climate change denier’ when we talk of geological time.  That said, the GWH lobby likes to label any scepticism as being of this nature and the choice of the term ‘denier’, with its Holocaust overtones, is simply an insult.

Proposition 2: Climate changes over ‘historical’ timescales

It gets a little harder now!  What do we mean by ‘historical’ and for that matter ‘climate’ as well?  The notion of a climate as ‘the sequence of weather we have learned to expect’ carries with it two bits of baggage.  The first is that a time scale is implicit whenever we use the idea of probabilities of occurrence of anything in the natural world.  The second is that climate is a construction made by human beings. All the atmosphere knows about is the ‘weather’.  In this sense it’s very easy to change a climate: change your definition of the ‘climate’, usually altering the time period of interest!  This sounds ‘academic’, but in some sense it is what the GWH has done in its attempts to persuade us that climate is changing, they have shortened the timescale and so increased the chance of showing a change.

If we look over the past five hundred years or so, then it’s clear that there have been changes in the climate that have forced adaptation by human societies on quite massive scales.  In all this it’s easy to forget that until the last forty years or so our own Meteorological Office itself wasn’t too keen on the notion of significant climate change over the timescale of a human lifetime.  It is also easy to forget that the scholarship of people like Hubert Lamb and Gordon Manley in establishing the reality of significant  historical climate change was until recently thought to be an esoteric and not very ‘scientific’ backwater in climate research.  I count myself fortunate to have known both and have been taught by one of them.

Proposition 3: Climate changes over historical timescales and there is an unusual recent global warming

Things get harder still when we bring in ideas of things being ‘unusual’.  The observational evidence of the recent global warming is often much more equivocal than the GWH scientists, greens, and the media like to suggest and the current warming phase isn’t as unusual as the warmers like to pretend.  We could have a long debate on this, but one example will suffice. Loss of ice from the Greenland Icecap is often cited as evidence of global warming, but this is based almost entirely on the accessible parts of the south east where the ‘ice fiord’ (Jacobshavn) pumps icebergs into the Davis Strait and the outlet glacier is surging and down-wasting. The careful work by other scientists that suggests that as a whole the Greenland ice cap has a total mass balance that, if it is changing at all, is changing within the limits of experimental error.  From time to time its outlet glaciers ‘surge’, and have done so for millennia.  The real problem here is that, computer climate models aside, climatology is an observational science, and like geology it is subject to what I call the tyranny of the ruling theory.  What happens is that a theory is elevated to the status of truth and all observations are subsequently made with this truth in mind.   Environmental science has fooled itself before in this way, notable over the reality or otherwise of ‘continental drift’ or the total nonsense that was called denudation chronology based on an utterly wrong model of how landscapes evolve.  Lest practitioners of the Queen of the sciences (Physics) get smart here, there are numerous examples in their discipline that could be cited, most obviously the great Lord Kelvin’s famous, arrogant, and utterly wrong, assertion about the age of our planet.

Proposition 4: Climate changes over historical timescales, there is an unusual recent global warming, and that it is carbon dioxide driven

This is one step further down the chain and it gets harder still.  What is the proof?  Almost every bit of evidence cited by GWH is equivocal, subject to a different interpretation.  Examples, in no special order include:

• Al Gore’s temperature and carbon dioxide curves and the infamous ‘hockey stick’. First the curves don’t match during the period of the supposed human induced warming, failing to show the 1940s cooling and being generally out of step. Second, the Medieval warm period has been airbrushed out of the record by a devious use of base period. Anyhow, as many of the GWH would argue were it some other pair of curves, correlation like this in time can’t logically prove causation;
• The computer models. These models almost all show that if you add carbon dioxide you increase temperature to balance the planet’s energy budget. It’s important to see how these work and how they are fine-tuned. As Mandy Rice Davis said in a different context ‘They would wouldn’t they?’. Unfortunately, criticizing the models is difficult without doing a PhD or two in atmospheric physics along the way, but suffice it to say that their results aren’t as solidly based as you are often led to believe. That IPCC and the GWH industry choose to rely on the model outputs rather than observation says as much about pecking orders in the British scientific establishment as it does about climate change;
• The direction of the link. On the longer timescale of the last glacial-interglacial cycle, there is evidence of a link between carbon dioxide in the air and global temperature, well illustrated by Al Gore in An Inconvenient Truth. However, every time I look at these plots and analyze the data on which they are based, the conclusion I draw is that temperature leads carbon dioxide, not as is often asserted by the GWH lobby. If there is causation, it is the other way round, temperature drives carbon dioxide and the mechanism might well involve out-gassing from the oceans as the solubility of the gas changes. It doesn’t mean that there isn’t a problem, but it may mean that there are long-memory oceanographic changes that aren’t anywhere in the models for the perfectly respectable reason that by and large we don’t understand them.

Proposition 4: Climate changes over historical timescales, there is an unusual recent global warming, that is carbon dioxide driven, and the source of the extra carbon dioxide is human activity

We are getting into very difficult territory now, largely because until recently the global carbon cycle and budget hasn’t been too well understood.  What is important to realize is that the atmospheric content of carbon dioxide is a small fraction of that locked elsewhere in the planet.  Quite small changes in these non-atmospheric reservoirs could generate huge percentage changes in the atmospheric content and in a geological perspective almost certainly has.  In the true spirit of science I admit that my knowledge of carbon cycling isn’t good enough to have a view on this.

Proposition 5: Climate changes over historical timescales, there is an unusual recent global warming that is carbon dioxide driven, the source of the extra carbon dioxide is human activity, and the warming will be bad for mankind

It is one thing to produce a computer model of a huge and complex system like the global atmosphere, add some carbon dioxide and watch what happens.  It is quite another to factor into this both the detail of the regional pictures and the effects of any changes on human activity.  We are now in realms of social science that are much less certain.  This has been attempted by IPCC and is often used to justify their use of the complex atmospheric models that predict where the warming will be seen as well as how much.  Suffice it to note that under a warmed world it looks as though there will be both winners and losers and it’s very hard to predict who will be in each category.  From a UK perspective chances are we’d be OK, but this is no reason to sit on the sidelines and wait.

Proposition 6: Climate changes over historical timescales, there is an unusual recent global warming that is carbon dioxide driven, the source of the extra is from human activity, the warming will be bad for mankind, and we can only put this right if we massively reduce the output of carbon into the atmosphere

Let’s call this the IPCC/Kyoto notion.  We have reached it by way of several degrees of scepticism, but we can be just as sceptical about this proposition. Let’s call it the Lomberg/Lawson position in acknowledgement of two economists trying to handle the implications of the entire edifice.  First, as events and the data have shown since Kyoto, the strategy is totally unworkable.  Second, it may well not even be the best way to tackle the problem. In the 1960s there was a fashion amongst climatologists for studying what were called climatic hazards.  Most turned out to be analyses of the economic impacts and mitigation strategies for hazards such as drought, flood, hurricanes, tornados, and snowstorms.  Without exception they showed that the sensible coping strategy isn’t to try to change the physics of the causal processes, yet this is precisely what Kyoto is suggesting for global warming, which might be the ultimate climatic hazard. Instead they suggested various coping strategies such as adaptation and adjustment.  I note with interest that the great James Lovelock has recently come out strongly in similar vein over the global warming hazard.

Proposition 7: Climate changes over historical timescales, there is an unusual recent global warming that is carbon dioxide driven, the source of the extra is from human activity, the warming will be bad for mankind, we can only put this right if we massively reduce the output of carbon into the atmosphere and if we don’t we’ll trigger a ‘runaway greenhouse’ that bakes the planet.

This is the final GWH nightmare.  They could be right, but if they are it’s probably too late!  ‘Que sera’ as Doris Day used to sing.  It’s comforting to note that not too many climate scientists actually hold this position, and this includes several of the better known global warmers.

All of this is not to deny the sense in reducing dependence on fossil fuels.  But there is a far better set of arguments about this that ought to be deployed.  If we forgot about ‘global warming’, and looked rationally at energy supply problems, I doubt that a ludicrously expensive, landscape disfiguring, and physically inconvenient power source such as onshore wind farming would figure in our calculations.

And, in case you doubt it, I like to think that in holding this view and in my general lifestyle I am reasonably ‘green’.

David Unwin