AGU’s New Climate Change Statement Emphasizes Human Role

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Thirteen approve, with one official and very vocal dissenter:  Roger Pielke Sr dissents as AGU adopts new statement saying ‘urgent action’ needed on climate.

It was a pull-no-punches American Geophysical Union revised climate change statement that drew the support of all but one of the 14 AGU members chosen to rework the update prior to its release.

But that one, Roger A. Pielke Sr, of the University of Colorado at Boulder, in his dissent threw some pretty sharp elbows at the panel and its chairman.

It was inevitable from the start, and Pielke Sr’s resistance and opposition came as no surprise to the other panel members. He had been raising a fuss throughout the whole process — “incredibly persistent” is how one participant described him. And all the committee members except he clearly reflected the “consensus” climate science views, including in particular those concerning the preeminent importance on risks posed by mounting CO2 emissions and concentrations.

Leaning Too Far from Science…and Into Policy?

The pointed headline of the AGU statement — “Human induced climate change requires urgent action” — held nothing back and prompted some criticisms that it veered too far from science and into policy.

AGU logo “In hindsight, I wonder if it’s too strong,” committee chair Gerald North of Texas A&M University later allowed, insisting the overall statement had steered clear of value judgments “except for the headline and the first sentence.” [The first two sentences, italicized and centered under the headline on the AGU website, read: "Humanity is the major influence on the global climate change observed over the past 50 years. Rapid societal responses can significantly lessen negative outcomes."]

“Extensive, independent observations confirm the reality of global warming,” the statement reads at one point, and “the changes are inconsistent with explanations of climate change that rely on known natural influences.”

“In addition, human-induced climate change may alter atmospheric circulation, dislocating historical patterns of natural variability and storminess,” the statement reads.

‘Surprise Outcomes’ Foreseen…but not ‘Inconsequential’ Impacts

“While important scientific uncertainties remain as to which particular impacts will be experienced where, no uncertainties are known that could make the impacts of climate change inconsequential. Furthermore, surprise outcomes, such as the unexpectedly rapid loss of Arctic summer sea ice, may entail even more dramatic changes than anticipated.”

To diminish threats posed by a warming climate, the AGU statement points to “substantial emissions cuts” and adaptation, but it does not mention or advocate a particular strategy — such as carbon taxes or cap-and-trade. “The community of scientists has responsibilities to improve overall understanding of climate change and its impacts,” it continues. It encourages scientists to go beyond just pursuit of research needed to better understand climate change.  Climate scientists in addition should work with stakeholders to identify key information, and convey their understandings “clearly and accurately, both to decision makers and to the general public.”

Pielke Sr Asserts Deck Was Stacked From the Start

Pielke, considered an outlier by those in the so-called “mainstream” climate science consensus community, used the climate.etc site headed by Georgia Tech climate scientist Judith Curry (also considered an outlier) to blast the process and what he felt was a predetermined result. He said group leaders “had a course of action in mind even when we were appointed.”

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Pielke complains considerations focused too much on CO2 and other GHGs.

Under the chairmanship of Texas A&M University climate scientist Gerald North, Pielke wrote, the panel considerations were “dominated by consideration of CO2 and a few other greenhouse gases,” and “other views were never given an opportunity to be discussed.”

The North-chaired panel, appointed by AGU’s Council leadership team, last November had published a draft of the updated statement in AGU’s weekly EOS newsletter. That draft statement — with Pielke Sr dissenting then too — contained some wording that is omitted from the final statement. Some of that earlier-included terminology appears to have been included to reflect some of Pielke Sr’s preferences:

At the regional and local level, other human influences, as well as short-term natural variations, can modify the large-scale warming caused by heat-trapping-gas increases. Thus, warming is not expected to be smooth over space or time. Deforestation, urbanization, and particulate pollution can have complex geographical and seasonal effects on temperature, precipitation, and cloud properties.

Regional vs. Global Perspective

It’s that kind of reasoning that appears, judging from the statement he posted at Curry’s site, likely to appeal to Pielke Sr. But the following sentences from that draft document better reflect the other panelists’ views, and that wording too is omitted from the final statement along with the text indented above: “On the global scale, the net effects of land surface changes are small relative to the warming caused by the burning of fossil fuels, but particulate pollution offsets a significant part of this warming.”

The final version of the AGU statement does include language discussing those issues, however. For instance, it changes “warming” to “climate change” in saying it “is not expected to be uniform over space and time” and that deforestation, urbanization, and particulate pollution can have complex effects. The final statement also says that “some areas may experience cooling,” but it adds that “this raises no challenge to the reality of human-induced climate change.”

Complimenting Pielke Sr as an AGU Fellow and as a “very good scientist,” North in a phone interview said “Roger is an expert on the mesoscale, on weather,” and “we all see this problem through our own lens.” He said Pielke Sr’s focus on “the regional scale” rather than global tends to downplay most climatologists’ perspective that over the next century CO2, in particular, “just keeps on going, is something that’s growing and by 2100 will dominate everything.”

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Gerald North chaired AGU panel revising climate statement and defends panel focus on CO2 and not issues like land use or urbanization.

Asked about Pielke Sr’s comments that the panel in effect had predetermined its emphasis and outcome and that it was not receptive to broader discussion, North said the committee had been “kind of charged with dealing” with those issues it addressed in the final statement. While saying he does not disagree in major ways with Pielke’s preference of a full statement, posted at the Curry site, North said “I believe he [Pielke Sr] has an agenda.” (Pielke [did not respond  to a request] could not be reached for comments or reactions.)*

Calling his own approach “more balanced,” Pielke’s alternative statement is one that Curry said she would “vastly prefer.” In commenting on the matter on her site, Curry wrote that she thinks the revised AGU statement “is one of the worst I’ve seen from a professional society on this topic,” and she singled-out the headline, quoted above, for particular scorn, calling it “an explicit statement of advocacy.” But she mistakenly objected that the subject of uncertainty was not used in the statement, which in fact pointed to “important scientific uncertainties” as noted above. (Pielke Sr’s affiliation is also incorrectly stated on the Curry website.)

None of which, it turns out, is likely to have come as a surprise to North and his other committee colleagues, many of whom are well known to have taken positions on climate science substantially different from those supported by either Pielke or Curry.

The AGU weekly newsletter to members, EOS, is expected in its August 20 edition to carry a report on the report and also on Pielke Sr.’s dissent.

The full AGU committee charged with preparing and reviewing the new statement includes, in addition to Pielke Sr. and North:

  • Amy Clement, Rosenstiel School of Marine and Atmospheric Science, University of Miami
  • John Farrington, Woods Hole Oceanographic Institute
  • Susan Joy Hassol, Climate Communication
  • Robert Hirsch, U.S. Geological Survey
  • Peter Huybers, Harvard University
  • Peter Lemke, Alfred Wegener Institute
  • Michael Oppenheimer, Princeton University
  • Ben Santer, Lawrence Livermore National Laboratory
  • Gavin Schmidt, Goddard Institute for Space Studies, NASA
  • Leonard A. Smith, London School of Economics
  • Eric Sundquist, U.S. Geological Survey
  • Pieter Tans, National Oceanic and Atmospheric Administration

North told The Yale Forum he had had no role in naming panel members but had been asked to review and approve them when AGU asked him to chair the panel. He said he had suggested that Leonard Smith of London School of Economics be added to the panel, but otherwise accepted it as presented, fully anticipating likely challenges from Pielke Sr.

Under AGU policies, such position statements expire in four years if they are not reviewed and updated as needed. The North committee was charged with reviewing and updating an existing one dated 2012 and first published in 2007.

Climate policy statements such as those from AGU, the American Association for the Advancement of Science (AAAS), and the American Meteorological Society (AMS) are often seen as barometers of the collective “pulse” of the science community on issues having public policy significance. But they often are known also to generate controversy among some elements of their memberships.

No major scientific society having expressed a policy statement on climate science has moved to temper its statement in the face of withering objections from climate “contrarians” and others within or beyond their own membership. The skeptical blogosphere will no doubt erupt should that ever happen.

North said the panel had received only about two-dozen member comments on the draft when it was published for comment last November. He said also that “it was amazing to me” that in the initial weeks since adoption of the new AGU statement he had received so few “hate mails” compared to his prior experiences with such statements. He said he wonders if there is “a tapering off” among climate skeptics, particularly with the passing of some prominent and skeptical engineers. But he also said he personally does not read blogs or other postings where such rants and criticisms continue to run rampant.

* Editor’s Note:  Dr. Pielke is correct in challenging this statement as initially published. Efforts to contact him ran afoul of his voice message suggesting callers use e-mail to reach him or his assistant. The original article should have made that clear.) Updated 8/23/13.

Bud Ward

Bud Ward is editor of Yale Climate Connections. (E-mail:
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24 Responses to AGU’s New Climate Change Statement Emphasizes Human Role

  1. Dan Pangburn says:

    Average global temperature history since 1975 is like a hill. We went up the hill from 1975 to 2001 where the average global temperature trend reached a plateau (per the average of the five government agencies that publicly report average global temperature anomalies). The average global temperature trend since 2001 has been flat to slightly declining but is on the plateau at the top of the hill. Claiming that the hill is highest at its top is not very profound. The temperature trend has started to decline but the decline will be slow; about 0.1 K per decade for the planet, approximately twice that fast for land areas.

    A licensed mechanical engineer (retired) who has been researching this issue (unfunded) for 6 years, and in the process discovered what actually caused global warming and why it ended, has four papers on the web that you may find of interest. They provide some eye-opening insight on the cause of change to average global temperature and why it has stopped warming. The papers are straight-forward calculations (not just theory) using readily available data up to May, 2013.

    The first one is ‘Global warming made simple’ at It shows, with simple thermal radiation calculations, how a tiny change in the amount of low-altitude clouds could account for half of the average global temperature change in the 20th century, and what could have caused that tiny cloud change. (The other half of the temperature change is from net average natural ocean oscillation which is dominated by the PDO)

    The second paper is ‘Natural Climate change has been hiding in plain sight’ at . This paper presents a simple equation that, using a single external forcing, calculates average global temperatures since they have been accurately measured world wide (about 1895) with an accuracy of 90%, irrespective of whether the influence of CO2 is included or not. The equation uses a proxy which is the time-integral of sunspot numbers (the external forcing). A graph is included which shows the calculated trajectory overlaid on measurements.

    Change to the level of atmospheric CO2 has had no significant effect on average global temperature.

    The time-integral of sunspot numbers since 1610 which is shown at corroborates the significance of this factor.

    A third paper, ‘The End of Global Warming’ at expands recent (since 1996) measurements and includes a graph showing the growing separation between the rising CO2 and not-rising average global temperature.

    The fourth paper exposes some of the mistakes that have been made by the ‘Consensus’ and the IPCC

    • Tony Duncan says:


      great news. Now get these papers published in peer reviewed journals. I have read so many people who have completely overthrown climate science yet none of them publish their work. it seems a shame.

      • Dan Pangburn says:

        Tony – Part of the problem is that the ‘name’ journals have been publishing the AGW stuff for many years and they don’t want to admit that they have been wrong, although eventually they will have no choice. I have a paper that has been through peer review and may appear in a ‘fringe’ journal this fall. Meanwhile, much of my stuff is on line for anyone to challenge.

        • Ah yea the grand conspiracy.

          It’s all because those bad scientists hate corporations and are striving for a one-world gov’ment… or something like that, right.

          And the heat waves during this cooling trend are just an artifact.

    • Science incest is best says:

      Dan I prefer the “Pal Review” route where I can get a paper published in a matter of weeks and not have provide data or code so that I don’t have to worry about “outsiders” checking my work.

      • Dan Pangburn says:

        Sci – Where do you publish? I’m OK with technologically competent people checking my work.

        It might not be realized by some, but average global temperature actually has little to do with meteorology so the wrong experts have been trying to figure it out. The so-called Global Climate Models (aka General Circulation Models) are actually weather models and they do a fair job of predicting weather for a few days. However, their predicting ability declines into computational noise within days. It is profoundly naïve to perceive that a weather model can be turned into a climate model by running it longer.

        • Philip Cohen says:

          I believe your comment about GCUs is false; only one (HADCRUT, as I recall) is also a weather model.

          I’m sure that your comment about GCUs’ predictability is as idiotic as claiming that because predictive ability declines quickly it is impossible to predict that December in the northern midlatitudes will be colder than June. I recommend for an antidote.

          Here’s a chunk from it:

          A common argument heard is “scientists can’t even predict the weather next week – how can they predict the climate years from now”. This betrays a misunderstanding of the difference between weather, which is chaotic and unpredictable, and climate which is weather averaged out over time. While you can’t predict with certainty whether a coin will land heads or tails, you can predict the statistical results of a large number of coin tosses. In weather terms, you can’t predict the exact route a storm will take but the average temperature and precipitation over the whole region is the same regardless of the route.

          • Philip Cohen says:

            GCUs’ predictION ability.

          • Dan Pangburn says:

            Phil – I have read there are about 73 so-called GCMs or AOGCMs. Just because they are called climate models does not mean that they actually are climate models. The assessment is mine that they are, in effect, weather models. My assessment is based on the knowledge that the results from the type of program that they all use degrades to computational noise in a relatively few computational steps. Why this happens is included in the discussion of GCM (or AOGCM) models in

            Most of us can predict that “…December in the northern mid-latitudes will be colder than June” because we know that the earth’s axis is tilted. It certainly doesn’t demonstrate that a computer program is valid.

            CO2 increase from 1800 to 2001 was 89.5 ppmv (parts per million by volume). The atmospheric carbon dioxide level has now increased since 2001 by 25.59 ppmv (an amount equal to 28.6% of the increase that took place from 1800 to 2001) (1800, 281.6 ppmv; 2001, 371.13 ppmv; July, 2013, 396.72 ppmv).

            The average (5 reporting agencies) global temperature trend since 2001 is flat. Figure 1 in is through April but the average through July is not significantly different.

            That is the observation. No amount of spin can explain how the temperature increase to 2001 was caused by a CO2 increase of 89.5 ppmv but that 25.59 ppmv additional CO2 increase had no effect on the average global temperature trend after 2001. This does demonstrate that the climate models that many climate scientists and the IPCC depend on are conspicuously wrong.

            The ‘coin toss’ argument reveals a fundamental lack of understanding of how the models work. You have been hoodwinked.

        • Garhighway says:

          Dan: Sci is playing you. He hasn’t had anything published.

          So he’s like you in that regard.

          My question is why you haven’t tried? If your work is that straightforward (and revolutionary) any good journal would be happy to publish it, if it services review.

          • Garhighway says:

            “Survives”, not “services”.

          • Dan Pangburn says:

            Gar – I try to not question other’s motives.

            I had an opinion piece published approximately three years ago. Nearly all of my work is available on line for anyone to challenge. All necessary information, links and sub-links are provided.

            See my Aug 21, 1:52 PM post above for the latest on my peer reviewed article status.

            There are a lot more papers submitted for publication than actually get published. I have found no one else who has discovered the startlingly excellent connection between average global temperature and the time-integral of sunspot numbers. Thus the immediate impulse of initial editors is to discount the work, although the usual answer is ‘not enough space’. Besides that, some journals charge a fee to publish a paper and I am unfunded.

    • Peter says:

      I hear of such papers all the time. Most likely, they will not pass peer review. I know you conveniently believe that the reason they fail this process is bias by the reviewers. But the real reason they fail is that they are scientifically unsound.

      One other point. Why would you believe a retired mechanical engineer over climate scientists with years of education and experience in that field unless you are biased.

      • Dan Pangburn says:

        As to ‘peer review’ there is this quote, available in Wikipedia, by Richard Horten, editor of the Lancet “But we know that the system of peer review is biased, unjust, unaccountable, incomplete, easily fixed, often insulting, usually ignorant, occasionally foolish, and frequently wrong.” So-called ‘peer review’ is de facto censoring.

        Typically, climate scientists are trained in meteorology. Average global temperature actually has little to do with meteorology so the wrong experts have been trying to figure it out. It is more correctly understood as a problem in radiation heat transfer, and a fairly simple one at that (or at least simple for a licensed mechanical engineer like me with 9 units of post graduate thermodynamics). It consists of only average surface temperature and effective surface emissivity and average cloud altitude (temperature) and average effective cloud emissivity or of slight change in average cloud area. As shown at sustained increase in average cloud altitude of less than 200 meters (and thus reduction in average cloud temperature and reduction of energy radiated to space) or a sustained decrease of albedo (or reflectivity which is a bit more than albedo) from 0.3 to the slightly lower value of 0.2928 would account for all of the 0.74 °C average global temperature increase of the 20th century. Climate scientists have a penchant for getting mired in the minutia.

        • Garhighway says:

          “Typically, climate scientists are trained in meteorology.”

          As a broad characterization I think that fails. Most of the climate science I read comes from people whose degrees are in physics or statistics.

          And most denier memes fail because of their ignorance of the physics of the problem: they want to ascribe relationships between our climate and (pick your choice) “cycles”, sunspots, ocean currents and other trifles and fail to address the underlying physics of the GHE.

          Watt’s a weatherman, not a scientist. That may be at the root of his problem.

  2. jan says:

    Dr. Pielke seems to have a penchant for ignoring the dominant role of co2

    And yet he speaks about the bias of others?

  3. Paul Quigg says:

    Why did the global temperature fall from approx. 1945 to approx. 1975 while at the same time co2 emissions rose dramatically. The correlation between emissions and temperature is poor but it eventually gets back on track and moves in an opposite direction. Talking about events since 1998 is weather, we need another 15 to 20 years of data to call the results climate.

    • Dan Pangburn says:

      Paul – The equation in the climatechange90 link uses 116 years of data. It accurately calculates the temperature trajectory since before 1900 and corroborates that change to the level of atmospheric CO2 has had no significant influence on average global temperature.

  4. For those who want to read my minority statement, it is available from here

    Pielke Sr., R.A. 2013: Humanity Has A Significant Effect on Climate – The AGU Community Has The Responsibility To Accurately Communicate The Current Understanding Of What is Certain And What Remains Uncertain [May 10 2013]. Minority Statement in response to AGU Position Statement on Climate Change entitled: “Human-induced Climate Change Requires Urgent Action” released on 8/5/13.

    Also, despite what is written in the article, I was not contacted to comment.

  5. Dan Pangburn says:

    Pilke Sr. – How do you reconcile ‘human activity having a significant effect on climate’ with the equation in ? The equation calculates average global temperatures since before 1900 with an R2 of 0.9 with no human influence and the only external forcing considered being the sunspot number time-integral. The equation also calculates approximate average global temperature trends since 1610 which includes the Little Ice Age.

    Any human influence must find room in the unexplained 10% which must include all factors not explicitly considered including the random uncertainty in reported measurements which has a standard deviation of approximately 0.1 K.