It isn't clear whether Bob Ward, former manager of policy communication at the Royal Society in London, knew quite what he was letting himself in for when he penned a letter taking the oil company ExxonMobil to task for funding groups that deny the human role in global warning. But with hindsight the result was predictable: once his letter was published by the British Guardian newspaper, the Royal Society was denounced from all quarters as having overstepped its role as an impartial custodian of science.

Inevitably, Ward's letter fuels the claims of 'climate sceptics' that the scientific community is seeking to impose a consensus and to suppress dissent. But the Royal Society has been denounced by less partisan voices too. David Whitehouse, formerly a science reporter for the BBC, subsequently wrote his own letter on the subject, which also wound up online: "My disquiet about this is...about the nature of the debate and the role of the Royal Society in it and the sending of such a hectoring and bullying letter demanding adherence to the scientific consensus," he wrote. "Is it appropriate that it should be using its authority to judge and censor in this way?"

And Roger Pielke, director of the University of Colorado's Center for Science and Technology Policy Research in Boulder, who is a controversialist but far from a climate sceptic, says, "The actions by the Royal Society are inconsistent with the open and free exchange of ideas, as well as the democratic notion of free speech."

Yes, there is nothing like the scent of scientific censorship to make scientists of all persuasions come over all righteous about free speech.

The problem is that these critics do not seem to understand what the Royal Society (or rather, Bob Ward) actually said, nor the context in which he said it, nor what the society now stands for.

Bullies?

ExxonMobil's 2005 corporate citizenship report said that the conclusions of the United Nations' Intergovernmental Panel on Climate Change (IPCC) — that recent global warming has a human cause — "rely on expert judgement rather than objective, reproducible statistical methods". Having read this, Ward wrote his letter to Nick Thomas, director of corporate affairs at ExxonMobil's UK branch Esso, and expressed surprise and disappointment at the assertion. His suggestion — that ExxonMobil's claim is "inaccurate" — is putting it far too politely.

The objections have focused, however, on Ward's alleged insistence that ExxonMobil stop funding climate-change deniers — he estimates that ExxonMobil provided $2.9 million last year to US organizations that "misinformed the public about climate change". Actually, Ward makes no such demand. He points out that he expressed concerns about the company's support for such lobby groups in a previous meeting with Thomas, who told him that the company intended to stop it. Ward simply asks in his letter when ExxonMobil plans to act on that intention.

So there is no demand here, merely a request for information. Whitehouse and Pielke are wrong in what they allege (the Guardian news story didn't help matters). But was the Royal Society wrong to intervene at all?

Anyone who is surprised that it has done so simply hasn't being paying attention. Under outspoken presidents such as Robert May and Martin Rees, the Royal Society is no longer the remote, patrician and blandly noncommittal body of yore. It means business. In his 2005 Anniversary Address, May criticized "the campaigns waged by those whose belief systems or commercial interests impel them to deny, or even misrepresent, the scientific facts".

And on this particular issue, Ward also rightly ridicules the notion of ExxonMobil as the frail David to the Royal Society's "bullying" Goliath. The Royal Society is no imperious monarch, but more like a rather elegant yet cash-strapped aristocrat who lives in the crumbling family pile. In contrast, the climate sceptics count among their number the most powerful man in the world, who has succeeded in emasculating the only international emissions treaty we have.

From all sides

It's not just the oil industry (and its political allies) that the Royal Society faces. The media is full of scientific illiterates banging out false claims.

Neil Collins wrote a column about this little spat in Britain's Daily Telegraph newspaper, saying, "Sea level does not appear to be rising" (wrong) while "the livelihoods of thousands of scientists depend on our being sufficiently spooked to keep funding the research" — don't even get me started on this recurrent idiocy.

I fear the scientific community does not appreciate the real dangers posed by this kind of expensively educated posturing from high places.

If not, it ought to. In the early 1990s, the then editor of the Sunday Times Andrew Neil supported a campaign by his reporter Neville Hodgkinson suggesting that HIV does not cause AIDS. Seems to me that, like most climate sceptics, Neil and the HIV-deniers didn't truly care about having a scientific debate — their agenda was different. Perhaps to them the awful thing about the HIV theory was that it placed every sexual libertine at risk, regardless of orientation. How dare science threaten to spoil our fun? Instead, they blamed the disease on some characteristic of homosexual sex. For a time, the Sunday Times campaign did real damage to AIDS prevention in Africa. But now it is forgotten and the sceptics discredited, while Neil has gone from strength to strength as a media star.

On that occasion, Nature invited accusations of scientific censorship by standing up to the Sunday Times ' programme of misinformation (see 'Media make AIDS wish come true') - making me proud to be working for the journal. As I recall, the Royal Society remained aloof from that matter (though May draws the analogy with climate-change sceptics in his 2005 speech). We should be glad that it is now apparently ready to enter the fray. Challenging powerful groups that distort science for personal, political or commercial reasons is not censorship, it is being an advocate for science in the real world.

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