Posted 22 January 2010

"The lower troposphere temperature record, although normally said to be 'consistent with' the greenhouse hypothesis, is actually only so to the extent that error bars overlap.... The effect of changes in the Sun's behaviour on weather patterns - whether via radiance changes, variation of the magnetic field, shielding from cosmic rays or other mechanisms - is usually dismissed as too small to be the primary driver of observed changes. ... Acknowledging the validity of these points and working to resolve them in an open-minded way would be a major step in the right direction. Treating opponents with respect would be another. " The Scientific Alliance, UK.

 The Scientific Alliance

22 January 2010 

The true impact of climategate and glaciergate

After such an intense focus on climate change late last year, I had made a private vow to keep off the topic in early 2010 and instead address other interesting and important issues. But in light of the truly extraordinary recent events, a further comment is simply irresistible.

'Climategate' - the furore over the implications of the leaked emails from the Norwich-based Climate Research Unit - has been interpreted by some sceptics as proof that the whole issue is simply a scam. Their judgement has been reinforced by a second scandal which, inevitably, some have labelled 'glaciergate' (a prize should go to the first person to find a snappy alternative to this label: Nixon resigned over 35 years ago!). The IPCC's Fourth Assessment Report, published in 2007, included a reference to the likely disappearance of Himalayan glaciers by 2035, which turned out to be based on an unsubstantiated statement in a WWF report, which itself may or may not have been quoting a simple typographical error: 2035 instead of 2350.

Rajendra Pachauri , current chairman of the IPCC, had last year criticised a state-of-the-art review issued by the Indian government as 'voodoo science' because it offered a more nuanced view of the varied behaviour of glaciers in the Himalayas and concluded that their retreat in recent years had not been abnormal. The recent disclosure could not be dismissed so lightly, but it was noticeable that Pachauri left it to his deputy, Jean-Pascal van Ypersele , to admit that a mistake had been made. In a (possibly vain) attempt at damage limitation, he is quoted by the BBC as saying 'I don't see how one mistake in a 3,000-page report can damage the credibility of the overall report. Some people will attempt to use it to damage the credibility of the IPCC; but if we can uncover it, and explain it and change it, it should strengthen the IPCC's credibility, showing that we are ready to learn from our mistakes.'

Perhaps unsurprisingly, many sceptics have gleefully put the boot into Pachauri (who is also being criticised for his opulent lifestyle and various alleged conflicts of interest) and, indeed, the entire climate change industry. Since these are the same people who have been the subject of numerous personal attacks on their credibility - including repeated allegations that they are merely paid lackeys of 'Big Oil' - the opportunity to turn the tables will have been irresistible to some.

Having been disparagingly referred to as 'village idiots' and 'flat earthers' by senior figures in the scientific establishment, the temptation must have been strong. But it should have been resisted. The various revelations should be treated rationally and cautiously and not simply used as a blunt weapon to discredit opponents. Climate change science and appropriate policy responses remain crucial issues, and ultimate decisions should be made on the basis of a calm assessment of the facts rather than simply siding with whoever has captured the headlines.

In reality, these two disclosures do not change the situation on climate change, even though they do pose questions about the objectivity of some key people. The enhanced greenhouse effect remains a plausible but unproven hypothesis, with a significant number of question marks hanging over it. The most important question is not whether carbon dioxide warms the Earth, but by how much. Cool heads should prevail and reasonable people on both sides of the argument must respect the honestly-held views of those they disagree with if there is to be any meeting of minds. The situation is no different from any human conflict; one side may overcome the other by force of arms, but diplomacy is needed to build a lasting peace.

Anyone attending events on climate change will be aware of their partisan nature. Go to a mainstream conference and a good proportion of the participants will assume that anyone who does not go along with the received wisdom of the IPCC is at best foolish or deranged and at worst an evil right-winger who will do anything for money. Attend one of the smaller number of events organised by sceptics and the position is reversed, except that evil right-wingers become evil left-wingers.

Of course, things are not quite as black and white as this. But, as with any caricature, the views of opponents can have some elements of truth. There are some radical people on both sides of the argument who simply will not admit that anything they say could be wrong. And there are clearly many researchers and others whose income is directly linked to the work they do and so implicitly to the views they (apparently) hold. As for politics, there is also a tendency for academics and environmentalists to hold left of centre views, while sceptics are often (but not always) further to the right.

These are broad generalisations, but we ignore them at our peril. The conclusions people come to on climate change are shaped by their general world view. Many people are very ready to believe that our species' impact on the planet is largely negative, and it is a short step then to seeing climate change as 'obviously' anthropogenic. From the other end of the spectrum, it is all to easy to see those wedded to this hypothesis as part of a conspiracy designed to promote world government and global socialism, to protect the environment at the expense of the individual.

But we should try to put our prejudices aside and look at some of the areas of scientific uncertainty which need to be the subject of objective research rather than cursory dismissal. The IPCC's leaders should realise that arrogance, obfuscation and contempt for justified critics play into the hands of the very people they appear to despise. A little humility and a willingness to take criticisms seriously would greatly strengthen their position.

It all comes down to avoiding double standards. People from both sides of the argument should realise that, in Oscar Wilde 's words, the truth is rarely pure and never simple. Finding a relatively small error in a publication or film does not automatically discredit everything else in it. But neither can errors simply be glossed over or ignored. Neither side has the truth, the whole truth and nothing but the truth.

So, in conclusion, here are two issues which deserve proper consideration by mainstream scientists rather than the normal brusque dismissal:

·        The lower troposphere temperature record, although normally said to be 'consistent with' the greenhouse hypothesis, is actually only so to the extent that error bars overlap. Its support for the hypothesis is rather weak, and yet it is a crucial part of the jigsaw. This issue needs to be resolved.

·        The effect of changes in the Sun's behaviour on weather patterns - whether via radiance changes, variation of the magnetic field, shielding from cosmic rays or other mechanisms - is usually dismissed as too small to be the primary driver of observed changes. But there is good historical correlation between solar cycles (eg, the number of sunspots) and observed long-term weather patterns, at least regionally. Given the accepted low level of understanding of clouds and atmospheric aerosols, solar influences surely merit proper investigation.

Acknowledging the validity of these points and working to resolve them in an open-minded way would be a major step in the right direction. Treating opponents with respect would be another.