[Update: The ever helpful David Roberts of Grist Magazine points out that an op-ed in the Washington Times yesterday makes the same logical error that I point out in this post below made by Patrick Michaels -- namely that short-term predictive failures obviate the need for action. The op-ed quotes me and says that I am "not previously a global warming skeptic," which is correct, but implies that somehow I am now . . . sorry, wrong. It also quotes my conclusion that climate models are "useless" without the important qualifiers **for decision making in the short term when specific decisions must be made**. Such models are great exploratory scientific tools, and were helpful in bringing the issue of greenhouse gases to the attention of decision makers. I've emailed the author making these points, asking him to correct his piece.]

Here I’d like to explain why one group of people, which we might call politically active climate scientists and their allies, seek to shut down a useful discussion with intimidation, bluster, and name-calling. It is, as you might expect, a function of the destructive politics of science in the global warming debate.


We’ve had a lot of interest of late in our efforts to explore what would seem to be a simple question:

What observations of the global climate system (over what time scale, with what certainty, etc.) would be inconsistent with predictions of the IPCC AR4?

The motivation for asking this question is of course the repeated claims by climate scientists that this or that observation is “consistent with” such predictions. For claims of consistency between observations and predictions to have any practical meaning whatsoever, they must be accompanied by knowledge of what observations would be inconsistent with predictions. This is a straightforward logical claim, and should be uncontroversial.

Yet efforts to explore this question have been met with accusations of “denialism,” of believing that human-caused global warming is “not a problem,” of being a “conspiracy theorist.” More constructive responses have claimed that questions of inconsistency cannot really be addressed for 20-30 years (which again raises the question why claims of consistency are appropriate on shorter timescales), have focused attention on the various ways to present uncertainty in predictions from a suite of models and also on uncertainties in observations systems, and have focused attention on the proper statistical tests to apply in such situations. In short, there is a lot of interesting subjects to discuss. Some people think that they have all of the answers, which is not at all problematic, as it makes this issue no different than most any other discussion you’ll find on blogs (or in academia for that matter).

But why is it that some practicing climate scientists and their allies in the blogosphere appear to be trying to shut down this discussion? After all, isn’t asking and debating interesting questions one of the reasons most of us decided to pursue research as a career in the first place? And in the messy and complicated science/politics of climate change wouldn’t more understanding be better than less?

The answer to why some people react so strongly to this subject can be gleaned from an op-ed in today’s Washington Times by one Patrick Michaels, a well-known activist skeptical of much of the claims made about the science and politics of climate change. Here is what Pat writes:

On May Day, Noah Keenlyside of Germany’s Leipzig Institute of Marine Science, published a paper in Nature forecasting no additional global warming “over the next decade.”

Al Gore and his minions continue to chant that “the science is settled” on global warming, but the only thing settled is that there has not been any since 1998. Critics of this view (rightfully) argue that 1998 was the warmest year in modern record, due to a huge El Nino event in the Pacific Ocean, and that it is unfair to start any analysis at a high (or a low) point in a longer history. But starting in 2001 or 1998 yields the same result: no warming.

Michaels is correct in his assertion of no warming starting in these dates, but one would reach a different conclusion starting in 1999 or 2000. He continues,

The Keenlyside team found that natural variability in the Earth’s oceans will “temporarily offset” global warming from carbon dioxide. Seventy percent of the Earth’s surface is oceanic; hence, what happens there greatly influences global temperature. It is now known that both Atlantic and Pacific temperatures can get “stuck,” for a decade or longer, in relatively warm or cool patterns. The North Atlantic is now forecast to be in a cold stage for a decade, which will help put the damper on global warming. Another Pacific temperature pattern is forecast not to push warming, either.

Science no longer provides justification for any rush to pass drastic global warming legislation. The Climate Security Act, sponsored by Joe Lieberman and John Warner, would cut emissions of carbon dioxide — the main “global warming” gas — by 66 percent over the next 42 years. With expected population growth, this means about a 90 percent drop in emissions per capita, to 19th-century levels.

He has laid out the bait, complete with reference to Al Gore, claiming that recent trends of no warming plus a forecast of continued lack of warming mean that there is no scientific basis for action on climate change.

There are several ways that one could respond to these claims.

One very common response to these sort of arguments would be to attack Michaels putative scientific basis for his policy arguments. Some would argue that he has cherrypicked his starting dates for asserting no trend. Other would observe that the recent trends in temperature are in fact consistent with predictions made by the IPCC. This latter strategy is exactly the approach used by the bloggers at Real Climate when I first started comparing 2007 IPCC predictions (from 2000) with temperature observations.

The “consistent with” strategy is a potential double-edged sword because it grants Pat Michaels a large chunk of territory in the debate. Once you attack the scientific basis for political arguments that are justified in those terms, you are accepting Michaels claim that the political arguments are in fact a function of the science. So in this case, by attacking Michaels scientific claims, you would be in effect saying

“Yes while it is true that these policies are justified on scientific conclusions, Pat Michaels has his science wrong. Getting the science right would lead to different political conclusions that Michaels arrives at.”

Here at Prometheus for a long time we’ve observed how this dynamic shifts political debates onto scientific debates. Any I discuss this in detail in my book, The Honest Broker (now on sale;-).

Now, the “consistent with” strategy is a double-edged sword because the future is uncertain. It could very well be the case that there is no additional warming over the next decade or longer, or perhaps a cooling. Given such uncertainty, scientists with an eye on the politics of climate change are quick to define pretty much anything that could be observed in the climate system as “consistent with” IPCC predictions in order to maintain their ability to deflect the sort of claims made by Patrick Michaels. For if everything observed is consistent with IPCC predictions, there is no reason to then call into question the scientific basis used to justify policies.

But this strategy runs a real risk of damaging the credibility of the scientific community. It is certainly possible to claim, as some of our commenters have and the folks at RC have, that 20 years of cooling is “consistent with” IPCC predictions, but I can pretty much guarantee that if the world has experienced cooling for 20 years from the late 1990s to the 2000-teens that the political dynamics of climate change and the standing of skeptics will be vastly different than it is today.

Now I am sure that many scientist/activists are just trying to buy some time (e.g., buy offering a wager on cooling, as RC has done), waiting for a strong warming trend to resume. And it very well might, since this is the central prediction of the IPCC. Blogger /activist/scientist Joe Romm gushed with mock enthusiasm when the March temperatures showed a much higher rate of warming than the previous three months. We’ll see what sort of announcement he or others put up for the much cooler April temperatures. But all such celebrations, on any side of the debate, do is set the stage for the acceptance of articles like that by Pat Michaels who point out the opposite when it occurs. One way to buy time is to protest, call others names, and muddy the waters. This strategy can work really well when questions of inconsistency take place over a few months and the real world assumes the pattern of behavior found in the central tendency of the IPCC predictions, but if potential inconsistency goes on any longer than this then you start looking like you are protesting too much.

So what is the alternative for those of us who seek action on climate change? I see two options, both predicated on rejecting the linkage between IPCC predictions and current political actions.

1) Recognize that any successful climate policies must be politically robust. This means that they have to make sense to many constituencies for many reasons. Increasing carbon dioxide in the atmosphere will have effects, and these effects are largely judged to be negative over the long term. Whether or not scientists can exactly predict these effects over decades is an open question. But the failure to offer accurate decadal predictions would say nothing about the judgment that continued increasing carbon dioxide is not a good idea. Further, for any climate policies to succeed they must make sense for a lot of reasons — the economy, trade, development, pork, image, etc. etc. — science is pretty much lost in the noise. So step one is to reject the premise of claims like that made by Pat Michaels. The tendency among activist climate scientists is instead to accept those claims.

2) The climate community should openly engage the issue of falsification of its predictions. By giving the perception that fallibility is not only acceptable, but expected as part of learning,it would go a long way toward backing off of the overselling of climate science that seems to have taken place. If the IPCC does not have things exactly correct, and the world has been led to believe that they do, then an inevitable loss of credibility might ensue. Those who believe that the IPCC is infallible will of course reject this idea.

Who knows? Maybe warming will resume in May, 2008 at a rapid rate, and continue for years or decades. Then this discussion will be moot. But what if it doesn’t?