The IPCC is showing typical signs of middle age, including weight gain, a growing rigidity of viewpoint, and overconfidence in its methods. It did a great job in the early days, but it’s become ritualized and bureaucratic, issuing big bulk reports that do little to answer the hard questions facing policymakers. – David Keith, as cited by Fred Pearce
Well, it seems the IPCC is no longer a ‘delinquent teenager.’
Fred Pearce has written an interesting article at Yale Environment 360 entitled Has the U.N. Climate Panel Now Outlived Its Usefulness? The subtitle is ‘Some scientists are saying that the latest report from the IPCC is overly conservative and fails to mention some of the more worrisome possible scenarios. The panel, they contend, is no longer fulfilling its mission of informing policy makers of the risks of global warming.’
While Pearce is clearly in the camp of ‘our perilous greenhouse future,’ he invariably provides thoughtful and new insights in his writing. The parts of his IPCC article that I found particularly provocative are excerpted below:
Some of those involved in the report process believe the natural caution among scientists — coupled perhaps with a wish not to repeat some exaggerations that marred some previous IPCC reports, and the effect of politicians looking over their shoulders — has created a report that is overly conservative, even biased, in its conclusions. Rather than lowering its expectations of warming, these scientists say, perhaps the panel should be raising them.
Some “scary scenarios” arising from possible positive feedbacks — in which nature amplifies man-made warming — have been left out of the model projections on which the IPCC’s headline forecasts are based. Surely, some critics say, it is the scary scenarios that politicians need to know about if they are to do their duty under the UN climate change convention and act together to prevent “dangerous climate change.” Even the U.S. signed that, under George Bush senior in 1992.
Another contentious topic was how the report should deal with the recent warming hiatus. The draft acknowledged the scientists’ concerns and noted that climate models “do not generally reproduce the observed reduction in surface warming trend over the last 10-15 years.” This was reportedly met with opposition from some delegates who wanted to remove all references to a slowdown. Some argued that the hiatus had not lasted long enough to be considered a temperature trend. Perhaps they also felt it would be seized on by climate-change deniers.
“We looked at this very carefully,” said Stocker. There was, he noted, “not a lot of published literature” on the phenomenon. This was a problem, since the IPCC does not do its own research and can only review published literature. But again, the authors of that passage stuck to their guns, and retained most of the message, though the direct statement about the failings of the models does not appear in the report.
Science is not naturally a consensual process. Reaching agreement is hard for people more used to spending their time refuting each others’ hypotheses. So the question arises: Is the IPCC’s self-imposed task of producing massive consensual documents about every aspect of climate science — and then resisting politicians’ efforts to change them — worth it?
For one thing, the consensus even among scientists is creaking. In interviews with Yale Environment 360 in recent weeks, a number of past and present IPCC authors have expressed strong dissatisfaction with what they saw as the conservatism of the emerging text for the scientific assessment. (There is, if anything, even more contention over the two companion reports that will be published next year, covering the impacts of climate change and what to do about it.)
Some researchers are angered about the marginal reduction in predicted warming. They say that may be justified by the outputs of the climate models, but that those models do not include some worrying positive feedbacks that could accelerate warming in coming decades. Other critics say that, even though the report has upped its estimates of sea level rise this century to as much as one meter, the lead authors did not accept findings from reputable researchers suggesting that a rise of as much as two meters was possible.
The problem, in essence, is that factors that climatologists cannot yet successfully model are left out of the modeling studies that deliver the headline predictions.
“I agree there can be a conflict between good science and what policymakers and engineers like flood designers want to know,” said Tony Payne of the University of Bristol, England.
Nicholas Stern of the London School of Economics, author of an influential economic assessment of climate change for the British government in 2006, takes a similar view about the failings of the IPCC and its models. He
The question is now being asked: Is the IPCC still fit for its purpose?
complained at a meeting at the International Monetary Fund in Washington, D.C., in April that “the scientific models mostly leave out dangerous feedbacks.” He called for “a new generation of models [that] focus on understanding probabilities of events with severe consequences for people [rather than] those effects that can be modeled more easily.”
For more than two decades, since it was created by the UN in 1988, the IPCC has done the job politicians asked of it: to synthesise scientific thinking around climate change and deliver a series of consensus assessments to policymakers. In the process, the IPCC won the Nobel peace prize in 2007. But the question is now being asked: Is the IPCC still fit for its purpose? It may do good science, but does it deliver what policymakers need?
JC comments: While coming at this from a very different perspective than my own IPCC diagnosis – permanent paradigm paralysis, we reach some similar conclusions. I particularly like posing this in terms of ‘fitness for purpose.’ Pearce also emphasizes the other side of the two-edged sword of uncertainty, namely that we have failed to focus on articulating the plausible worst case scenarios that could emerge in the 21st and even 22nd centuries associated with a combination of natural and anthropogenic climate change.
With regards to Pearce’s question:
It may do good science, but does it deliver what policymakers need?
I have argued that the IPCC consensus seeking process is getting in the way of doing the science that is most needed to support the needs of policy makers, namely decadal variability on regional scales and also the plausible worst case scenarios.
I don’t think the IPCC can be fixed or reinvented in a way that is useful.