A few weeks ago we posed a challenge to both parties involved in the so-called “hockey stick” debate to explain why the rest of us ought to care about the debate. We asked, “so what?” We received responses from Steve McIntyre and Ross McKitrick while everyone on the other side declined to participate, though a few showed up in the comments. Here I’d like to offer a few assorted reflections on the responses and the subsequent discussion.

1. First, thanks to Steve McIntyre (SM) and Ross McKitrick (RM) for providing thoughtful responses. The responses motivated a healthy discussion and for me provided some greater insight into the dynamics of the ongoing debate within the climate community not just over the hockey stick, but broader issues as well.

2. Interestingly enough, the response from SM is completely in agreement with RealClimate contributors Stefan Rahmsdorf (SR) and William Connelley (WC) that the “hockey stick” debate is pretty much irrelevant to the scientific question of whether or not greenhouse gases will affect the future climate. Consider:

SR: “The discussions about the past millennium are not discussions about whether humans are changing climate; neither do they affect our projections for the future.”

WC: “Why is this fight important to the rest of us? the answer is: you shouldn’t. It isn’t..”

SM: “I’m inclined to agree that, for the most part, the Hockey Stick does not matter to the great issue of the impact of 2xCO2.”

This agreement is interesting because it means we can move beyond the often invoked assertion that the hockey stick is the keystone supporting the entire scientific basis of climate science. Others may assert that the hockey stick is a scientific keystone, but apparently not the principals involved in this debate.


3. But the agreement among the parties raises a very interesting set of questions that have much more to do with climate science policy than climate policy. First among these questions is a very good point raised by both SM and RM, if the hockey stick doesn’t matter to the case for greenhouse gas effects on climate, why was it included and featured in the Summary for Policy Makers in the Second Assessment Report of the Intergovernmental Panel on Climate Change? SM provides a compelling answer to this question, “So even if the Hockey Stick did not “matter” to the scientific case, it mattered to the promotion of the scientific case.” The role of the SPM and the “promotion” of science by IPCC officials is a fair subject for discussion, independent of the answers to the technical questions M&M are debating with Mann et al.. Ultimately, the hockey stick debate is relevant to policy questions, but these questions have more to do with how we think about and organize science for policy, than any particular questions of climate policy itself.

4. RM suggests that the hockey stick is a symbol of the fidelity of journal peer review, the credibility and legitimacy of the IPCC, and how governments (in this case Canada) use scientific symbols to promote particular policies. It seems to me that MM sure could have made these points a lot more prominently early on. I am more convinced about the importance of the IPCC and journal peer review than the argument about the influence of the hockey stick on Canadian climate policies, but I am open to the case being made. I see that MM briefly raise the issue of journal peer review in their 2005 publication in Energy and Environment (PDF) and nothing comes up in their GRL publication (PDF). SM did raise some of these issues on his blog last February and in a related op-ed. RM raises some of these issues in this conference paper (PDF). But these are pretty hard-to-find nooks and crannies. My unsolicited advice to SM and RM is to spend more time (a lot more time) talking about the “so what?” questions as they pursue the obscure technical details. (By all means pursue the obscure and technical, but if indeed you care about the broader issues, then it is the broader issues that matter most.) They might find themselves with some allies if they talk more about peer review in science and international assessments, for which there are many people with interests and concerns. Pretty much all I do is “so what?” related to climate science, and I did not understand the positions of M&M until they wrote these essays. All of us are more likely a tool of those seeking to use our work for their purposes if we do not clearly and repeatedly (ad nausem) stake out your claim to the “so what?” ground. Perhaps, one reason that the folks on the other side chose not to participate may be their desire to leave the “so what?” ground open for occupation.

5. The concerns raised by SM and RM about the IPCC are part of a much broader set of experiences that raise questions about the credibility, legitimacy and salience of the IPCC. SM is perfectly justified in asking questions about the IPCC. We are all stakeholders in the IPCC process, and there appears to be no independent venue for raising issues about the IPCC process. The reception of the paleo climate community to M&M, regardless of the merits of their claims, is a good reason why such an independent venue makes sense. Certainly M&M could have been more tactful and diplomatically astute in their efforts, but still, the IPCC is the international organization responsible for bringing climate science and economics to policy makers, it can’t afford to be petty or aloof. I’d contrast the reception that Wentz and Mears received upon bursting on the scene with evidence that the Spencer/Christy satellite data was flawed. The dynamics here are easy to understand, and they can be found in all sorts of places, but it is the job of the IPCC to treat science and scientists fairly, not to protect a consensus or political symbols.

6. Finally a few comments about the discussion that followed. I continue to be amazed at the degree of tribal behavior that the climate community generates. Different camps give themselves and their opponents cute names — “hockey team,” “skeptics,” “contrarians, “mainstream”. They meet in club houses like RealClimate and ClimateAudit where they talk amongst themselves. A telling comment appeared early in the exchange when some one asked me if I was “embarrassed” to be providing a forum for RM. This tells me that some folks are less interested in resolving the climate debate than perpetuating it. I suppose the fight is good sport. But if progress is ever going to be made on the issue then people on different sides will have to meet, discuss and compromise. If I were a proprietor of RealClimate or ClimateAudit I would have some very real concerns about creating an “echo chamber“. Sometimes I wonder if these sites do less to educate their self-selected visitors than make their proprietors more strident and extreme in their own views, a la Cass Sunstein.

7. Finally, I found it amusing to find myself being attacked simultaneously on both the RealClimate website and the ClimateAudit website for being in the camp of the other. As one post said, “if you are not with us you are against us”. This perspective, which is held not only among anonymous blog commentators, but some scientists, issue advocates and politicians helps to explain why the climate debate is locked in stalemate, and everyone chooses to fight about science instead.

Thanks all for participating. If you have any suggestions for topics and contributors that we might invite in the future to engage one another, please send them along.