Consensus as the New Heresy

Gavin Schmidt, Michael Mann, David Archer, Stefan Rahmstorf, William Connolley, and Raymond Bradley

Andy Revkin, who’s one of the best journalists on the climate beat, wrote a curious piece in the NY Times discussing the ‘middle stance’ of the climate debate. It’s nice to see news pieces on climate that aren’t breathless accounts of a new breakthough and that take the time to point out that the vast majority of relevant scientists take climate change extremely seriously. To that extent, the message of this piece was a welcome one. The curious part, however, was the thread running through the piece that this middle ground is only now emerging, and even curiouser, that this middle ground can be characterized as representing some sort of ‘heresy’.

Heresy, is commonly defined as ‘an opinion or doctrine at variance with the official or orthodox position’. So where does this idea come from, and why is it now ’emerging’?

It has often been remarked upon that scientists and academics make their reputations by breaking down orthodoxies and by challenging previously widespread assumptions (but it will only work out well if they’re right of course!). Nobody makes much of a name for themselves by agreeing with all previous thinking. Indeed, to be thought of as a radical new thinker, one must assume the role of the heretic, challenging the stale orthodoxies of the past. And given some of the scientific iconoclasts in our pantheon (Galileo, Einstein, Wegner etc.), we see this as a completely natural state of affairs.

However, there is a big difference between really challenging the majority opinion and simply stating that you are. We are all often ‘contrary’, but here at RC we also generally find ourselves firmly in the mainstream on many of the central scientific points: e.g., our views on the most probable value of the climate sensitivity (around 3C), the likelihood of the imminent Gulf Stream reversal (zero), or the possibility of Venusian-style runaway greenhouse effect happening this side of a billion years (extremely small). That these positions are in line with conclusions drawn by IPCC is no surprise, because those reports result from intense discussion and peer-review involving a large fraction of the community, thus they reflect the views of the climate science community very well. Most scientists present these widely shared conclusions when speaking to the public, and where their own views diverge from it, they make it clear that these are their own conclusions rather than a generally accepted view.

In reading about the new ‘heretics’ then, one might have expected that associated with them would be statements that would contradict IPCC or that we (as mainstream scientists who do not claim to be heretics) would otherwise find objectionable. So let’s consider the specific tenets of the ‘new heresy’ mentioned in the article:

• From Carl Wunsch: ‘It seems worth a very large premium to insure ourselves against the most catastrophic scenarios. Denying the risk seems utterly stupid. Claiming we can calculate the probabilities with any degree of skill seems equally stupid’. Agreed.
• “Many in this camp seek a policy of reducing vulnerability to all climate extremes while building public support for a sustained shift to nonpolluting energy sources”. Sensible.
• There is “no firm evidence of a heat-triggered strengthening in storms in recent years” (our emphasis). Well, what the WMO statement to which this assertion is attributed actually said was (first bullet point): “Though there is evidence both for and against the existence of a detectable anthropogenic signal in the tropical cyclone climate record to date, no firm conclusion can be made on this point.” We agree with that statement – this particular subject is definitely in a state of flux.
• “Recent increase[s] in the impact of storms was because of more people getting in harm’s way, not stronger storms”. Again, the WMO report did not state this. What it stated was (third bullet point of statement; emphasis added): “The recent increase in societal impact from tropical cyclones has largely been caused by rising concentrations of population and infrastructure in coastal regions”. These are not quite the same. Once again, we agree with what the WMO actually said. Interestingly, the second bullet point of the WMO statement, not mentioned in the article, “No individual tropical cyclone can be directly attributed to climate change” was voiced by us more than a year ago.
• “Global warming is real, it’s serious, but it’s just one of many global challenges that we’re facing,”. Of course.
• From Mike Hulme: “I have found myself increasingly chastised by climate change campaigners when my public statements and lectures on climate change have not satisfied their thirst for environmental drama,” he wrote. “I believe climate change is real, must be faced and action taken. But the discourse of catastrophe is in danger of tipping society onto a negative, depressive and reactionary trajectory.” Agreed. And we said much the same thing when commenting on the ‘Climate Porn’ report.
• “It is best not to gloss over uncertainties”. Duh!
• “efforts to attribute recent weather extremes to the climate trend, though they may generate headlines in the short run, distract from the real reasons to act”. We couldn’t agree more, and have stated as much before.
• “‘An Inconvenient Truth’ may push too hard”. Perhaps at last, there is a (moderate) difference of opinion. We agree with Eric’s review of the movie earlier this year, i.e. while there were a few things to quibble with, Gore got the science basically right.

The only substantial disagreement, then, is over a movie review. On all other points of substance the ‘heresy’ and the old orthodoxy are the same.

We’ve emphasised over and over that the science that should inform policy should come from thorough assessment processes like the IPCC and the National Academies. The views of individual scientists (including us) should carry less weight – partly because of our specific biases (due to the field we work in or our personalities), and partly because a thorough discussion and peer review process (like that leading to IPCC reports) will lead to more considered, informed and balanced statements than any individual could muster. Media representations of what individual scientists supposedly said should not be used for policy at all!

Much of the sensationalist talk in the public discourse (and to which the scientists in the piece, and we, rightly take exception) are not the pronoucements of serious scientists in the field, but distorted and often out-of-context quotes that can be further mangled upon frequent repetition. We have often criticised such pieces (here, or here for instance) and it is important to note that the ‘shrill voices of doom’ referred to by Mike Hulme were not scientists, but campaigners.

John Fleck suggests that Revkin’s point was that the middle stance is only now being reflected in the media coverage, which for the highly polarised US discussion could be a valid point – although Revkin’s own work in the New York Times argues against it. So does the fact that all of the scientists discussed in this piece are veterans in media coverage of the issue; their view of things can hardly be called “just emerging”.

Perhaps the real background to Revkin’s piece simply is that some like to use the age-old debating tactic of labelling other views as “extreme” in order to position themselves in the “middle”. If you divide the world into ‘alarmists’ and ‘deniers’, you can then nicely present yourself as the ‘heretic’ who wants to break the mold. But this is a false distinction.

The plain fact is that the vast majority of scientific judgement on this issue – as outlined in the IPCC documents including the AR4 coming up in February- does indeed cover the ‘middle stance’, which we would state as being in agreement with the statement of the National Academies of the G8 last year that ‘the scientific understanding of climate change is now sufficiently clear to justify nations taking prompt action’. As Jim Hansen states in his quote – it’s still surprising that there are some people who don’t know this yet.

Further discussion on this piece is available: Matthew Nesbit, John Fleck, Roger Pielke Jr, David Roberts and Andrew Dessler. Also Joseph Romm.