CLIMATE CHANGE - HOW SCIENCE CAN DEFEAT THE SCEPTICS
Earlier this week the BBC Trust announced a comprehensive review of how the Corporation reports scientific controversy, which is of course politically sensitive over issues like Genetically Modified crops and Climate Change. The review is part of the BBC’s assessment of how it is meeting its charter obligations to be impartial.
The question of impartiality is a difficult concept in terms of scientific debate, particularly where there is a divergence between the common sense views held by lay people away from the scientific consensus of expert opinion. Channel 4 got themselves into trouble three years ago showing a “documentary” by Martin Durkin called “the Great Climate Change Swindle”that sought to undermine informed political debate by misrepresenting the balance of scientific opinion so as to give exaggerated weight to eccentrics. Durkin is of course associated with the libertarian network formerly known as the RCP, who are controversialists for the sake of it.
There is a good accessible guide to the debating tactics of “deniers” at Scienceblogs.com. One of the pertinent points they make is that some scientifically incompetent people not only have an exaggerated view of their own competence, but also fail to recognise genuine competence in others. As a result this minority not only DO NOT but CAN NOT distinguish between good science and crank theories.
Unfortunately, there has developed a sort of intellectual exhaustion over the issue of Climate Change, and scepticism has gained ground in the last couple of years, as can be seen from the huge response to the “Climategate” scandal surrounding leaked e-mails from University of East Anglia Climate Research Unit. Climate change deniers and sceptics have had a field day, and have been joined by libertarians and conspiracy theorists of all sorts. Indeed there was a huge explosion of Internet traffic on these sites. Derek Wall has pointed out that the irrationality of much of the scepticism, and Unity at Liberal Conspiracy made a very good attempt at explaining the issue of the Hockey Stick controversy as it relates to the deviation between tree ring data and global temperatures measured by a variety of other means over the last 20 years, although he has a rather more positive assessment of the credibility of the Hockey Stick than I do..
However, I believe it is also necessary to look at how scientists seeking to persuade the public and politicians of the need for urgent action have created problems themselves. For example, Wolgang Behringer’s excellent book “A Cultural History of Climate” quotes Stephen Schneider, a co-author of the 2001 Intergovernmental Panel on Climate Change (IPCC) report as saying: “To capture the public’s imagination … we have to offer up scary scenarios, make dramatic simplified statements”. The difficulty with this, apart from its elitism, is that it provides hostage to fortune where people with a poor understanding of scientific reasoning grasp at inaccuracies in the simplified message and obsess over them.
The best analysis I have read of the Climategate e-mail scandal is by Peter Kelemen, a professor of geochemistry at Columbia University’s Department of Earth and Environmental Sciences, in the journal Popular Mechanics.
He points out that
“Among the hundreds of e-mails, 10 to 20 messages seem to indicate that scientists at CRU and their correspondents considered deleting information requested by critics in the context of British and American freedom of information laws, and in at least two separate cases discussed how to have associate editors of peer-reviewed journals removed from their posts because they accepted critics’ papers for publication. We do not know the detailed context of these messages, nor do we know if ideas discussed in these e-mails were actually implemented. Furthermore, though CRU has confirmed that most of the e-mails are genuine, some of them could have been forged or altered. Nevertheless, I think it is important for scientists to clearly state that if basic data were withheld, or if there was unprofessional tampering with the peer-review process, we do not condone these acts. It is equally essential to emphasize that alleged problems with a few scientists’ behavior do not change the consensus understanding of human-induced, global climate change, which is a robust hypothesis based on well-established observations and inferences.”
If the e-mails have not been forged or altered then there are genuine causes for concern about some of the behaviours from the East Anglia academics. But the logical eror by the sceptics and deniers is to leap from the fact that this or that detail may be wrong, or this or that scientist may have made a mistake, into assuming that the whole of the science is wrong.
Unfortunately, the desire to present a simple story has also led to some bad science. In general this can be seen by the quasi-religious tones that the debate over the Hockey Stick is sometimes conducted, and the accusations of bad faith.
Behringer quotes a number of worrying examples of mystification from leading climate scientists. For example, James E Hansen, a Director of a NASA Institute and professor at the Earth Institute of Columbia University writes of climate change throwing the earth into “energy imbalance”. But what is the balance that it is being thrown from? Does he regard the particular holocene climate that the Earth has sustained for the last few thousand years as “balance” and everything else as imbalance? Behringer quotes two physicists who have been co-ordinating work with the IPCC writing of climate change as a disease! Noted geo-scientist, Richard Alley has referred to the quasi-religious concept of “ecosins” – i.e. he has introduced religious metaphor into science.
Seeking to popularise the science is a good thing, but if this leads to mystification then it obscures the debate rather than enhancing it. There is also a fundamental problem of seeking to create an artificial divide so that mankind’s activity is seen as occurring outside of and antagonistic to the natural world. The impact of living organisms upon climate is as old as life itself, as the composition of the atmosphere is largely shaped by the animal and plant life, and this in turn has huge impact on temperature. Mankind’s first major impact on climate probably started as long ago as the deforestation that accompanied the neolithic revolution.
There is a further real problem with the way some climate change scientists respond to the Hockey Stick debate. This refers to a graph of climate over the last 1000 years that shows an essentially stable temperature until the last hundred years, and then a sharp upswing (the foot of the hockey stick). This was included in the 2001 IPCC report, correlating it to CO2 levels, which show the same pattern.
While the CO2 graph is based upon data from recovered air bubbles drawn from ice core drilling, the constant value of 290 ppm in the pre-industrial era between 1000 and 1800 does suggest that perhaps the raw data has been sampled to exaggerate the later upwards trend. The temperature graph extrapolates the information for the period 1000 to 1750.
This is not really too problematic, as long as its limitations are acknowledged. But some of the most enthusiastic proponents of the Hockey Stick, like Michael Mann, feel forced to reject very empirically well established phenomenon, like the mediaeval warm period, where temperatures were higher than they were in the 20th century or today. For example, maximum tree line levels, the altitudes and latitudes that vines and wheat could be grown, the archaeological record of pollens and insect evidence; and even clothing trends in the mediaeval period prove that temperatures were higher then than today. Indeed, estimations of global temperatures over the last 2000 years derived from recent ocean floor drilling do not follow Mann’s Hockey stick, and match much more closely the 1990 IPCC calculations.
Populist accounts of global temperatures also tend to discount the global cooling that occurred between 1945 and 1975, that was indeed one of the foundations of modern climate research, as concern grew that interglacial periods rarely exceed 10000 years, and in the 1970s it was postulated that we were due for another Ice Age.
There are a number of things to say here. Firstly, the Earth’s climate is very complex, and variation in temperature is not monocausal. It is affected by the long wave variation in the Earth’s orbital distance from the sun; by sun-spot activity; by the amount of particulate in the atmosphere whether from volcanoes, meteorites, or pollution, which blocks the sunlight; it is also affected by the amount of reflection, itself a function of glaciation; over the very long term global temperature is even affected by continental drift. So the greenhouse effect, whereby water vapour, CO2, CH4 and some other trace gases trap the heat energy is only one causal agent among many.
The correlation between CO2 concentration and global temperature is very well established science, indeed first suggested in the nineteenth century by Baron de Fourier, and John Tyndall. The Greenhouse theory was first proposed in developed form by Glibert Plass in 1956, and was given empirical reinforcement when data showing the upward drift of CO2 concentrations was first published by Charles Keeling a year later. However, although a relationship between Co2 concentration and temperature is very firmly established, the mechanism may not be entirely straight forward, as there are feedback effects at work, whereby higher temperatures cause higher CO2, which can mean there is a Phase difference between the CO2 and the temperature trends.
The other thing that needs saying is that the way the consensus changed whereby climate scientists first predicted an ice age, and then changed to worrying about global warming is in fact a vindication of the scientific method, not its refutation. Stathis Psillis in his excellent 1999 book “Scientific Realism, How Science Tracks Truth” discusses in detail how working scientists distinguish between those parts of a theory which are empirically successful, and those parts which are contingent on further validation. His discussion concerns the nineteenth century theory of the caloric nature of heat as a material fluid; and the dynamical optimal ether theories of the same period, which attempted to explain the passage of light. Both of these theories were widely propagated and taught because they explained the observed behaviour better than alternate theories, but in neither case were predictive assumptions made upon the material existence of heat as a fluid or the ether as a physical structure. That is, they had explanatory power as hypotheses, but were always regarded as contingent.
The scientific impetus to studying global cooling began with J Murray Mitchell of the US Weather Bureau, who observed that the huge quantities of dust from atomic bomb testing had a different pattern of dust retention in the stratosphere from volcanoes. This led him to observe the effect of volcanoes on cooling the average global temperatures, and this drew attention to the steep rise in temperature during the first half of the Twentieth Century, since the end of the Little Ice Age in 1895. This led to Henry Kissinger in 1974 initiating international cooperation in climate change research in a speech in the United Nations, and it was the United States who further took the lead in 1978 of establishing both a national programme of research, and broad international research cooperation. During the 1970s, prompted by fears of global cooling, intensive research effort achieved much greater understanding of the causal factors behind temperature variation. Indeed plausible explanation of the cooled period between 1945 and 1975 comes from decline in sun-spot activity, and increased pollution providing a dimming effect.
So this is what we know, as established science.
i) there is a broad correlation between CO2 levels and global temperature,
ii) the greenhouse effect is only one causal factor, but it is an important factor
iii) CO2 concentrations are very steeply rising, to levels not achieved for millions of years
iv) Average temperatures have risen by 0.6 degree C over the last hundred years, and there has been a significant increase in the last 30 years
v) The rise in CO2 correlates with the explosion of air-flights, increase of animal husbandry for a more meat oriented diet, and growth of consumerism
This is quite enough to establish beyond reasonable doubt that climate change is real, and that there is a significant degree of human causation.
However, we must beware of politicization of the science whereby we assume that the general public are not sophisticated enough to understand that CO2 concentration changes are not the only factor that causes temperature changes. This feeds the scepticism. Paradoxically, where scientists and activists seeking to persuade people of the danger of climate change abandon the ground of strong science, then they open the door to deniers and sceptics arguing for more “balance” in the debate, so it is an own goal.
We must also resist the moralism of arguments along the lines that “people are killing the planet”. We are part of the planet, and we mould it to our own needs; the solution is not abandoning hope in science and technology, but embracing it further, and not only reducing CO2 emissions, but also exploring complementary counter-measures like carbon capture.
Incidentally, I strongly recommend “A Cultural History of Climate (Paperback)” by Wolfgang Behringer, Polity Press, November 2009. It is particularly strong on explaining the dramatic cultural and social changes that climate variations have had on humanity over the last thousands of years, and discussing the archival and physical evidence in a very compelling way. There is also a useful summary of the scientific debate. The illustration used above is Breugel’s Hunters in the Snow, which is used on the cover of Behringer’s book, showing the harsh climate during the mini ice age in late mediaeval Europe. All the graphs are taken from Behringer.

Those chinese are so inscrutable, and the Independent reveals today their real plans for world domination. Apparently China is “clamping down” on the export of rare earth elements (REEs) required for combatting global warming.
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