Well, neither causes the other, for a start. But both the anti-smoking lobby and the climate change lobby have their moderates and their hard-liners. [image by Stewart]

For example, New Scientist reports on a schism in the anti-smoking field:

… Siegel has come under fire from colleagues in the field of smoking research. His offence was to post messages on the widely read mailing list Tobacco Policy Talk, in which he questioned one of the medical claims about passive smoking, as well as the wisdom of extreme measures such as outdoor smoking bans.

In front of his peers, funders and potential future employers, other contributors posted messages accusing Siegel of taking money from the tobacco industry. When Siegel stood his ground, the administrators kicked him off the list, cutting off a key source of news in his field. “It felt like I was excommunicated, says Siegel. “I was shocked: I’ve been a leader in the movement for 21 years.”

The similarities with climate change should be obvious, what with that scene also being full of people coming to a variety of conclusions based upon the same evidence. As with the smoking issues above, the end-result is a form of in-fighting, with the more moderate thinkers decrying the hard-liners for making the moderate view unpalatable by association – take climate ‘tipping points’, for example:

In reports released this month, both the World Bank and the United Nations Environment Program focused on tipping points as a prime concern. And last year, a team of European scientists published an influential paper in the Proceedings of the National Academy of Sciences compiling what is known and not known about various climatic tipping points — including the loss of summer sea ice around the North Pole and worrisome changes in the West African monsoon.

The authors said they wanted to reduce the chance that “society may be lulled into a false sense of security by smooth projections of global change.”

On the other hand, the United Nations Intergovernmental Panel on Climate Change, in its influential 2007 report, expressly avoided specifying tipping points and instead concluded simply that the gradient of risk for a host of “large-scale discontinuities” increased with each degree of warming.

[snip]

As policymakers try to address the risks facing the planet from a warming climate, some experts worry that focusing on tipping points and thresholds will perpetuate paralyzing debates over specifics — and obscure the reality that decisions need to be made, even in the face of uncertainty.

What this makes abundantly clear is that – as climate skeptics are always keen to point out – scientific consensus isn’t like a choir singing in unison from the same song-sheet. And nor should it be… but it makes things very confusing for the layman, as increasingly frantic (and often inaccurate) media coverage makes it progressively more difficult to see the wood from the trees. All the scientists quoted in the article above agree that climate change is real and that we must act in light of that prognosis; however, the different ways in which they choose to interpret and communicate that data make that commonality less obvious.

Perhaps I stand to be accused of credulity myself, but I’m of the opinion that the vast majority of scientists – even those who claim that climate change is not a threat – are acting sincerely on their own beliefs rather than shilling for commercial or political interests. Do scientists with extreme and/or entrenched viewpoints overstate the cases made by the available data? Almost certainly; listen to any conversation about sports or music to hear ordinary people doing exactly the same thing. But do those extreme interpretations invalidate the more moderate thinking of those whose conclusions they have built upon? Not for me, at least. YMMV.