The folks at Real Climate have produced a very interesting analysis that provides some useful information for the task of framing a falsification exercise on IPCC predictions of global surface temperature changes. The exercise also provides some insight into how this branch of the climate science community defines the concept of consistency between models and observations, and why it is that every observation seems to be, in their eyes, “consistent with” model predictions. This post explains why Real Climate is wrong in their conclusions on falsification and the why it is that two decades of cooling can be defined as “consistent with” predictions of warming.

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UPDATE: Real Climate has already dismissed the paper linked below as a failed effort.

Climate Audit provides a pointer to this paper (PDF) by Koutsoyiannis et al. which has the following abstract:

As falsifiability is an essential element of science (Karl Popper), many have disputed the scientific basis of climatic predictions on the grounds that they are not falsifiable or verifiable at present. This critique arises from the argument that we need to wait several decades before we may know how reliable the predictions will be. However, elements of falsifiability already exist, given that many of the climatic model outputs contain time series for past periods. In particular, the models of the IPCC Third Assessment Report have projected future climate starting from 1990; thus, there is an 18‐year period for which comparison of model outputs and reality is possible. In practice, the climatic model outputs are downscaled to finer spatial scales, and conclusions are drawn for the evolution of regional climates and hydrological regimes; thus, it is essential to make such comparisons on regional scales and point basis rather than on global or hemispheric scales. In this study, we have retrieved temperature and precipitation records, at least 100‐year long, from a number of stations worldwide. We have also retrieved a number of climatic model outputs, extracted the time series for the grid points closest to each examined station, and produced a time series for the station location based on best linear estimation. Finally, to assess the reliability of model predictions, we have compared the historical with the model time series using several statistical indicators including long‐term variability, from monthly to overyear (climatic) time scales. Based on these analyses, we discuss the usefulness of climatic model future projections (with emphasis on precipitation) from a hydrological perspective, in relationship to a long‐term uncertainty framework.

The paper provides the following conclusions:

*All examined long records demonstrate large overyear variability (long‐term fluctuations) with no systematic signatures across the different locations/climates.

*GCMs generally reproduce the broad climatic behaviours at different geographical locations and the sequence of wet/dry or warm/cold periods on a mean monthly scale.

*However, model outputs at annual and climatic (30‐year) scales are irrelevant with reality; also, they do not reproduce the natural overyear fluctuation and, generally, underestimate the variance and the Hurst coefficient of the observed series; none of the models proves to be systematically better than the others.

*The huge negative values of coefficients of efficiency at those scales show that model predictions are much poorer that an elementary prediction based on the time average.

*This makes future climate projections not credible.

*The GCM outputs of AR4, as compared to those of TAR, are a regression in terms of the elements of falsifiability they provide, because most of the AR4 scenarios refer only to the future, whereas TAR scenarios also included historical periods.

I spent 8 years as a staff scientist at the National Center for Atmospheric Research in their social science group, where I saw little support for this important area of research. So the news that NCAR has decided to downgrade and scatter its meager social science resources comes as no surprise. Though at a time that the world more than ever needs such research, the decision is clearly short sighted. Because NCAR is base-funded by the National Science Foundation, it certainly would be appropriate for NSF to investigate the decision to diminish the role of social science and policy research at NCAR, and why it has been deemphasized at a time when policy makers more than ever need such knowledge.

Here is how NCAR announced the news in an email last week, which one insider characterized to me as being “blindsided”:

To All Staff,

NCAR is facing significant financial challenges. The NSF base budget has risen at a rate less than the cost of business in each of the past six years. Increasingly, this has put major stresses on the NCAR budget. In response to this prolonged budget stress, NCAR and UCAR management have been taking measures to allocate budgets based on NCAR strategic priorities and NSF mandates. We have also had to reduce direct and indirect costs. This included the reduction in staff of 36 NCAR positions over the past four years.

Even with these adjustments, we continue to face significant budget pressures. In response to immediate FY08 budget shortfalls and the outlook for FY09, additional actions are required to address the problem. One important move that we will be taking this week is to dissolve the Societal-Environmental Research and Education Laboratory (SERE) and administratively move the Advanced Study Program (ASP), Institute for the Study of Society and the Environment (ISSE), an Center for Capacity Building (CCB) into other parts of NCAR. This will save immediate and recurring direct and indirect costs, capitalize on economies of scale in other labs, and enhance synergy and collaboration through new partnerships. Unfortunately, this will result in reductions in staff in the SERE Director’s Office.

Next steps include:

* ISSE will receive administrative and management support through the Research Applications Laboratory (RAL).
* ASP will become a stand-alone Program that reports to the NCAR Director’s Office.
* CCB will also become a stand-alone Program that reports to the NCAR Director’s Office

We want to emphasize that these changes in no way diminish UCAR’s and NCAR’s commitment to ASP, ISSE, and CCB. Despite the current budget challenges, we remain dedicated to our vision of developing leadership in the social science components of climate and weather research, creating societal and policy-relevant research and information products, and conducting research on human-environment interactions.

Rick Anthes and Tim Killeen

The Real Climate guys have offered odds on future temperature changes, which is great because it gives us a sense of their confidence in predictions of future global average temperatures. Unfortunately, RCs foray into laying odds is not as useful as it might be.

The motivation for this bet is the recent Keenlyside et al. paper that has caused a set of mixed reactions among the commenters in the blogosphere. Some commenters here have stridently argued that the predictions in the Keelyside et al. paper are perfectly consistent with predictions of climate models in the IPCC. However, when one such commenter here was asked to show a single IPCC climate model run showing no temperature increase for the 2 decades following the late 1990s he submitted an irrelevant link and disappeared. Others have argued that the Keenlyside et al. projections (and this includes Keenlyside) are inconsistent with the IPCC predictions. Real Climate apparently falls into this latter camp.

The Real Climate Bet (and there is also one for a later period) is that the period 1994-2004 will have a higher average temperature than the period 2000-2010. Since the periods have in common 2000-2004, we can throw those out as irrelevant. Thus, the bet is really about whether the period 1994-1998 will be warmer than the period 2005-2010. And since we know the temperatures for 2005 to present, the bet is really about what will happen in 2009 and 2010. (Using UKMET temps here.)

It is strange to see the Real Climate guys wagering on 2-year climate trends when they already taught us a lesson that 8 years is far to short for trends to be meaningful. But perhaps there is some other reason why they offer this bet. That reason is that they are playing with a stacked deck, which is what you do when looking for suckers. The following figure shows why.

For the Real Climate guys to lose the bet global average temperatures for 2009 and 2010 would have to fall by about 0.30 from the period 2005-present (and I’ve assumed Jan-Mar as the 2008 value, 2008 obviously could wind up higher or lower). Real Climate has boldly offered 50-50 odds that this will happen. This is a bit like giving 50-50 odds that Wigan will come back from a 3-0 halftime deficit to Manchester United. Who would take that bet?

Another interpretation of the odds provided by RC is that they actually believe that there is a 50% chance that global temperatures will decrease by more than 0.30 over the next few years. Since I don’t think they actually believe that, it is safe to conclude that they’ve offered a suckers bet. Too bad. When Real Climate wants to offer a 50-50 bet in which the bettor gets to pick which side to take in the bet (i.e., the definition of 50-50) then we’ll know that they are serious.

On NPR’s Fresh Air earlier this week, Al Gore suggests that Typhoon Nargis, which may have killed 100,000 people in Myanmar, is linked to greenhouse gas emissions, or does he? He said “we’re seeing consequences that scientists have long predicted might be associated with continued global warming.”

What could he have meant? If you ask me, I’d say that the “consistent with” chronicles continue . . .

PS. Those wanting to do something positive in the face of this tragedy might visit this site.

Here is a very thoughtful comment sent in by email on the ““consistent with chronicles”. I haven’t identified the author, since he didn’t ask me to post it. But it is worth a read about how climate science is received by one rancher in West Tennessee. I appreciate the feedback.

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Over at his blog Iain Murray, who is with the Competitive Enterprise Institute, has a thoughtful response to my initial post on elements of any successful approach to climate change. I won’t try to summarize Iain’s lengthy post, so go there read it and come back. (Thanks to BP for the pointer.)

Here are some very quick responses of my own.

1. I appreciate Iain’s efforts to “propose an alternative framework that may be more appealing to conservative policy-makers.” In the U.S there is a wide gap between Democrats and Republicans on many aspects of climate policy. If this gap is to close in the form of shared agreement on action, it will result from having an open discussion of policies resulting in compromises, and not by the finger-pointing, name calling, and derision that so often accompanies political debates on climate change. As Walter Lippmann once wrote, the goal of politics is not to get people to think alike, but to get people who think differently to act alike.

2. On adaptation Iain and I see to agree more than disagree. I recognize that the concept of “sustainable development” carries with it much symbolic baggage and people read into the concept an awful lot. I don’t see a Malthusian perspective in the concept, far from it. I actually see that technological progress that eliminates limits and opens possibilities as key to sustainable development. There is much more to say, but on issues of technology and trade, i see no real significant disagreements here.

3. Iain is correct in pointing out the real costs associated with making carbon-based energy more expensive. This is the main reason that I see that its political prospects are seriously limited. But even so, Iain probably recognizes that what he calls “costs” are viewed by many people as “benefits”. That is, many people would like energy to be more pricier, even if it results in costs for some other people . For some, they focus on the non-market costs of carbon-based energy and thus evaluate the costs/benefits with some implicit valuation of the intangibles, but others simply prefer the outcomes associated with pricier energy. I have no expectation that people with vastly different values will come to agreement on costs and benefits associated with pricing carbon, hence, I see its prospects as limited in any case.

4. Iain likes the idea of making carbon-free energy “more affordable” but has some different recommendations than I do on how it might be done. Great. I don’t think that anyone has a magic bullet solution, so agreement on the goal ought to be a enormous first step in its achievement. This is one reason why I listed a laundry list of options. I would hope that Iain would agree that the world really hasn’t set forth in this direction in any real seriousness, at least not as compared to the intensity of action focused on pricing carbon. But we seem to agree on the goals here.

Iain has some more specific actions described at his blog that are worth a read. If anyone else wants to share their reactions to this discussion they are welcome to do so in the comments or as a guest blog.

This post summarizes, in capsule form, what I believe to be the necessary elements of any successful suite of policies focused on climate mitigation and adaptation. This post is short, and necessarily incomplete with insufficient detail, nonetheless, its purpose is to set the stage for future, in depth discussions of each element discussed below. The elements discussed below are meant to occur in parallel. All are necessary, none by itself sufficient. I welcome comments, critique, and questions.

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May 13, 2008. Roger Pielke Jr. CIRES, CU Boulder. “Have we underestimated the Carbon Dioxide Challenge?” Details. RedFish, 5:30PM, 2027 13th Street.

Scientists are fond of explaining that recent observations of the climate are “consistent with” predictions from climate models. With this construction, scientists are thus explicitly making the claim that models can accurately predict the evolution of those climate variables. Here are just a few recent examples:

“What we are seeing [in recent hurricane trends] is consistent with what the global warming models are predicting,” Thomas Knutson, a research meteorologist at a National Oceanic and Atmospheric Administration laboratory in Princeton, N.J., said Friday.
link

In a change that is consistent with global warming computer models, the jet streams that govern weather patterns around the world are shifting their course, according to a new analysis by the Carnegie Institution published in Geophysical Research Letters.
link

Francis Zwiers, the director of the climate research division of Environment Canada, said research consistently showed the addition of sulfate aerosols and greenhouse gases such as carbon dioxide into the atmosphere has changed rainfall patterns in the Arctic. Zwiers and his colleagues made their findings using 22 climate models that looked at precipitation conditions from the second half of the 20th century. Writing in the journal Science, Zwiers said these findings are consistent with observed increases in Arctic river discharge and the freshening of Arctic water masses during the same time period.
link

The fact that we are seeing an expansion of the ocean’s least productive areas as the subtropical gyres warm is consistent with our understanding of the impact of global warming. But with a nine-year time series, it is difficult to rule out decadal variation. link

All of this talk of observations being “consistent with” the predictions from climate models led me to wonder — What observations would be inconsistent with those same models?

Logically, for a claim of observations being “consistent with” model predictions to have any meaning then there also must be some class of observations that are “inconsistent with” model predictions. For if any observation is “consistent with” model predictions then you are saying absolutely nothing, while at the same time suggesting that you are saying something meaningful. In other contexts this sort of talk is called spin.

So I have occasionally used this blog to ask the question — what observations would be inconsistent with model predictions?

The answer that keeps coming up is “no observations” — though a few commenters have suggested that a temperature change of 10 degrees C over a decade would be inconsistent, as too would be the glaciation of NYC over the next few years. These responses certainly are responsive, but I think help to make my point.

Others, such as climate modeler James Annan, suggest that my goal is to falsify global warming theory (whatever that is):”no-one is going to “falsify” the fact that CO2 absorbs LW radiation”. No. James is perhaps trying to change the subject, as I am interested in exactly what I say I am interested in — to understand what observations might be inconsistent with predictions from “global warming models,” in the words of climate modeler Tom Knutson, cited above.

Others suggest that by asking this questions I am providing skeptics with “talking points.” The implication I suppose is that I should not be looking behind the curtain, lest I find a little wizard at the controls and reveal that we are all actually in Oz. How silly is this complaint? If the political agenda of those wanting action on climate change is so sensitive to someone asking questions of climate models that it risks collapsing, then it is a pretty frail agenda to begin with. I actually do not think that it is so frail, and in fact, my view is that the science, and policies justified based on scientific claims, will be stronger by openly discussing these issues.

A final set of reactions has been that climate models only predict trends over the long-term, such as 30 years, and that anyone looking to examine short-term climate behavior is either stupid or willfully disingenuous. It is funny how this same complaint is not levied at those scientists making claims of “consistent with,” such as in those examples listed above. Of course, any time period can be used to compare model predictions with observations — uncertainties will simply need to be presented as a function of the time period selected. When scientists (and others) argue against rigorously testing predictions against observations, then you know that the science is in an unhealthy state.

So, to conclude, so long as climate scientists make public claims that recent observations of aspects of the climate are “consistent with” the results of “global warming models,” then it is perfectly appropriate to ask what observations would be “inconsistent with” those very same models. Until this follow up question is answered in a clear, rigorous manner, the incoherent, abusive, and misdirected responses to the question will have to serve as answer enough.