The latest affair to be treated in this way is the leaking of a large batch of emails from the server of the University of East Anglia 's Climate Research Unit. These do not show some of the senior scientists (who monitor the Earth's temperature) in a particularly favourable light. In particular, the apparent efforts to avoid scrutiny of the raw data on which published temperature trends are based is decidedly unscientific behaviour, and has, not surprisingly, been leapt upon with enthusiasm by critics. George Monbiot , arch-priest of UK greenery, felt sufficiently betrayed to call for the resignation of Professor Phil Jones , head of the CRU and author of some of the emails. And the university is taking this seriously: Professor Jones is temporarily stepping down while the affair is investigated.

This whole affair says more about sociology than science. What we see is two groups with entrenched positions: the mainstream scientists at CRU and other institutions and an assorted range of sceptics who have varying degrees of concern about the current received wisdom. That the server was hacked and the emails made public was at least partly due to the fact that legitimate requests for the raw temperature data used by the CRU were repeatedly refused.

From the point of view of Professor Jones and his colleagues, those asking for the data were being a nuisance and simply seeking to find fault with their work. They therefore gave a range of excuses for not releasing the data (until it emerged that some of it had actually been dumped some years previously to save storage space!). Far from putting off the critics, it made them more determined to see the data, and the CRU unwittingly created the conditions which encouraged the hacker.

This is natural human behaviour, but should have no place in science. The essence of the scientific method is to test a hypothesis by collecting data and doing experiments. If it withstands this test, confidence in it improves, although this does not mean it will not be supplanted by a revised or even radically different hypothesis at some later date. Today's prevailing paradigm is that 'all knowledge is provisional' (although the certainty expressed by some climate scientists runs counter to this).

If researchers genuinely believe their work to be correct, they have nothing to fear from critics, even if they think they have malicious intent. Unsubstantiated attacks may be a nuisance and waste time in the short term, but refuting them further strengthens the original case. Some climate change researchers, in contrast, have been acting as though they are not confident in their work. Because of their refusal to be open and make their data freely available, they have damaged their cause. To what extent remains to be seen.

There are various theories about how these emails were made public: this may not have been a case of deliberate hacking, but rather that the material was inadvertently put on a server with public access. How they were obtained is not really the point; it is the content which is important. But double standards seem to abide on this point as well. Initial reports nearly all used the term 'stolen', which is unusual for this sort of case. Some of the same people who have deplored this would doubtless have been pleased to see material similarly 'stolen' which discredited a major oil company or, indeed, a group of sceptical scientists.

There is a parallel here with the treatment of sceptics by the environmentalist and scientific establishment. Ad hominem attacks are commonplace, with activists routinely suggesting that dissent is funded by 'Big Oil'. Rather than argue against their opponents - which surely puts them on a firm footing if the evidence is as irrefutable as they suggest - they try to discredit them. Many senior scientists are no better; even Lord Rees , President of the Royal Society, recently referred to climate sceptics as 'village idiots'.

The climate change issue - the defining issue of the first decade of the 21^st century - has exposed swathes of modern science to be little more than activism and advocacy for a sincerely held view. Scientists should be capable of taking part in rational dialogue, even if they profoundly disagree with each other. Resorting to name-calling is deeply regrettable.

Neither is this one-way traffic. The high-handed and dismissive behaviour of the climate change lobby has led to equally intolerant behaviour form the more radical wing of the sceptics. Some have been content to point out the unscientific behaviour in the CRU coterie, but others have made accusations of deliberate fraud. This spat has turned into a classic dialogue of the deaf, but hopefully the more reasonable voices on both sides of the debate will ultimately triumph.

But after all the talking, all the preparation and all the hype, the Copenhagen conference is finally upon us. Next week, the delegates will gather in the Danish capital, to be joined by selected world leaders - including President Obama  - some days later. The conference will finish on 18^th December, the best possible gloss will be put on whatever political agreement finally emerges, and the exhausted participants will begin to recuperate for the next round.

Not everyone who subscribes to the current global warming hypothesis wants success in Copenhagen , though. James Hansen , activist scientist par excellence, believes that the draft Copenhagen treaty is deeply flawed and would like to see it rejected so that the parties start from scratch. For the truly committed, no compromised is tolerable.

Yvo de Boer , head of the UN's climate change agency, has talked of a treaty being ready by next June. Maybe, but there is still a mountain to climb before a binding agreement is signed which would cover the post-Kyoto period. And even then, it is likely that many countries which ratify a future treaty will not feel bound to honour their commitments. Such has been the outcome of Kyoto .

In the meantime, the dual pressures of an economic crisis and a dubious public make real progress towards radical policy goals unachievable. 'Climategate' will not have made a radical difference, but it is part of the slow drip of inconvenient messages which are eroding the black and white message of 'the science is settled and we're all doomed'. To change metaphors in mid-paragraph, it is not unreasonable to suggest that the high tide of climate alarmism has been reached.