December 12, 2008, 5:19 am News

"Objective assessment of the current evidence, plus further unbiased gathering of evidence may reveal some inconvenient truths for the orthodox view. Or these truths may prove to be inconvenient for sceptics." In this first of two scholarly essays, the UK Scientific Alliance poses 6 questions that need answers.

21 November 2008

The climate change debate

Like climate science, the debate about climate change is complex. Like the science - and despite the protestations of the IPCC, the scientific establishment in most countries and a great number of highly reputable scientists worldwide - the outcome of the debate is far from clear.

The problem is that, just because so many people see it as such a crucial issue, many of them want to close down discussion and get on with tackling the problem. In their view, dissenting voices may reduce the commitment of politicians to taking urgent action, not least because public opinion will not be behind them.

Rather than take any critical comment seriously and put forward counter-arguments, the scientific, intellectual and political establishments across much of the world close ranks and say the debate is over. Because they will not engage in any constructive way, they disparage critics by questioning their credibility and motives, accusing them in many cases of being (horror of horrors) in the pay of "Big Oil". Worse, the term "denier" has been introduced as a catch-all smear, with its associations with the Holocaust.

Not surprisingly in these circumstances, some sceptics of the received wisdom can in turn be pretty scathing about mainstream scientists and politicians, and personal attacks and insults are not uncommon. The result is a dialogue (if indeed that is not too strong a word) of the deaf. People shout their views from their particular mountain top, only to hear seemingly unrelated answers drifting back from another peak. This is certainly neither constructive nor productive, and it is little wonder that many people (on both sides of the argument) with real contributions to make decide to put their heads back below the parapet.

This is not a satisfactory situation for anyone who cares about the primacy of scientific evidence over belief. It is certainly not good for those who may have the views of others imposed on them despite the evidence. Anyone who cares about these issues should get involved constructively and encourage others to do so.

Scientific Alliance members share a belief in the power of the scientific method and rational assessment of evidence to guide us towards wise decisions. Plausible hypotheses are proposed and tested. If they fail the test, they are discarded or revised. Unfortunately, the whole edifice of mainstream climate science is currently based on the output of algorithms run on supercomputers with a range of measured and projected data as inputs.

Assumptions are made, correction factors included, processes are tweaked, and the models are made to be consistent with past climate changes. On this basis, they are considered to be adequate to predict the future climate, even though a wide range of results emerge. The common factor they are all predicated on is an assumption that the small warming effect of atmospheric carbon dioxide is magnified by the additional water vapour contained in the warmer air. The net result is the generally-accepted (by the IPCC) prediction of a rise in the average temperature of several degrees over the next century.

This modelling exercise is taken as hard evidence rather than a "what-if" projection because the mainstream climate science community reckons it understands the global climate system well enough to detect the input of humankind against the natural background variation. Claims that proof has been found should be treated with great caution by all scientists when such "proof" is the output of complex computer models which are known to be only an incomplete representation of reality.

But the conventional theory (more correctly, hypothesis) of anthropogenic global warming has such a hold on people's imaginations that rather than question any of its pillars and attempt to falsify them as Popperian theory suggests, mainstream scientists look instead for supporting evidence. Taken to its extreme, we see the result in the popular media, where most current and future ills have at one time been blamed on increased atmospheric carbon dioxide levels.

At a research level, scientists report such things as rates of glacier retreat, loss of Arctic summer sea ice, coral bleaching and species decline as evidence of human-driven global warming. And virtually all the reported results are for negative impacts of rising temperatures; there are rarely any compensating upsides. There are also continuing attempts by some commentators to link natural disasters such as hurricanes to climate change, despite the lack of real evidence to support this view.

On the other hand, hard evidence which is at odds with the conventional view is generally met with a deafening silence. Such evidence is in any case increasingly hard to gather, since public funding of research is almost certainly not available for projects which question the prevailing orthodoxy. None of this is to say that the conventional wisdom is wrong, just that there are too many pieces of contradictory evidence and equally plausible alternative hypotheses for many scientists to accept it.

The Scientific Alliance promotes rational debate. It is interested in good policy decisions being based on hard evidence. In this spirit, the following is a partial list of questions which need to be seriously addressed rather than dismissed or sidestepped:

  • Is the role of such important influencers as the Pacific Decadal Oscillation (PDO), the North Atlantic Oscillation (PDO) and the El Niño Southern Oscillation ( ENSO ) understood to the extent that they can be predicted and their role in climate systems properly quantified?

  • Have observations on the influence of solar cycles (sunspots, solar wind variations and precession around the Solar System Centre of Mass) been properly assessed and tested?

  • Do we have any real understanding of the net effect of clouds on the Earth's climate?

  • Why is the warming of the upper troposphere inconsistent with the direct impact of carbon dioxide postulated by the IPCC?

  • Why does the greater part of Antarctica not show a warming trend as predicted?

  • Why has virtually all the measured warming occurred in the Northern hemisphere?

Objective assessment of the current evidence, plus further unbiased gathering of evidence may reveal some inconvenient truths for the orthodox view. Or these truths may prove to be inconvenient for sceptics. In either case, our knowledge will have been advanced and policies can be made on the basis of facts rather than model projections.


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