The Inconvenience of the IPCC

Inconvenient Truth movie poster

I see via Prometheus that David Roberts has taken up my challenge offered in the comments of a previous thread about whether Al Gore is representative of the mainstream consensus or an outlier (as suggested by Andy Revkin in his recent New York Times piece).

I argued that Gore’s treatment of hurricanes and sea level rise goes beyond the mainstream consensus on those issues. Roberts, in his new post, defends Gore:

Because the IPCC, held to punishingly conservative standards of peer-review and consensus, is silent on the hurricane question … does that mean everyone has to be silent? Al Gore chooses to pick a side, in effect predicting which way the chips are going to fall. In that he goes beyond the IPCC — and beyond what the relevant scientific community is willing to label consensus — but he doesn’t contradict the IPCC. He uses his judgment to supplement the IPCC. And he’s been right on this issue for decades, and understands it about as well as any layman on the planet, so I’m not inclined to brush his judgments aside.

It seems perfectly reasonable to me for him to say the following: “Based on some new and emerging research, and based on my sense of the direction of the science over the last 20 years, and based on my holistic understanding of the phenomenon, I believe global warming will increasingly make hurricanes measurably stronger and more destructive.”

I agree that Gore is free to do this in advancing his political arguments, but I think observers like Roberts need to recognize the slippery slope it represents.

The problem with this line of argument is that as soon as you sanction what Al Gore does here, you’ve sanctioned a general type of argument: “I believe, in this particular area of scientific uncertainty, the likely outcome of ongoing research is likely to be X, and we should therefore base our policy response on X.” I don’t think Inhofe is the best example, but the case of Benny Peiser’s obsession with solar influence might be a better one. Benny’s happy to cherrypick research on one side of this question (big solar influence on warming) and use it, based on his years of expertise, to argue that that’s where he thinks the science is heading. As soon as you sanction Gore’s use of the tactic, you’ve no grounds on which to argue against Benny’s use of the same line of argument.

That’s precisely the recipe for gridlock on “scientized” policy debates, which Dan Sarewitz has so eloquently demonstrated. Andrew Dessler is absolutely correct that we really have no choice in these debates but to try our best to identify and work within IPCC-style consensus.

Unfortunately, Sarewitz’s argument and my own personal experience as a journalist covering these controversies convinces me that the sort of thing we’re talking about here – picking outliers that support one’s value positions – is an inevitable state of affairs. Roberts’ willingness to do it, and endorse it, despite the obvious sophistication of his understanding of the issues, is one more bit of empirical evidence in support of what Sarewitz is saying.


  1. Good Heavens! I like consensus! But I do not trust the IPCC-style consensus, as long as IPCC is ignoring the recent global cooling from winter 1939/40 to the end of the 1970s.

    What we know now is that 2006 was the warmest of half a dozen years in the last half millennium, while the winters in the late 1930s had been the warmest for 450 years (except 1772). We also know that in late 1939 there was an El Niño event, as we have now. Back in winter 1939/40 the world was in World War II in the fourth months, which makes the difference. The weather than proved to be totally different, in January 1940 in the US, and even much more in North Europe, which was heading to the coldest winter for more than 100 years. Why? When thousand of naval vessels navigation the “warm-water reservoir” of the semi-enclosed North Sea and Baltic Sea for training, surveillance and fighting day and night, the stored summer heat is quickly gone and arctic winter conditions can take reign (for details see: , or ).

    But why was also the January 1940 extremely cold in the US? The TIME magazine from Dec. 25, 1939 concluded, that the “driest fall of record” was in 1939, and due to NYT (Jan. 7, 1940) the Weather Bureau noted that November 1939 was unusual because of its dry air. South Dakota and Wyoming had only 1%, and Nebraska and Minnesota only 5% of average rain during November 1939, (New Mexico 94%). On the other hand, in West Europe, particularly along the long war front between France and Germany with 2 million soldiers on each side the rain exceeded 300%. A link between these two events is possible (ditto).

    Having experienced the “driest fall” will pave the ground for the inflow of arctic air. The drier the soil, also the humidity in the air decreases, and the more likely high pressure can prevail. Back in 1939 the first signs of a real winter emerged at Christmas, when except for the Deep South and California the US had snow and extreme low temperatures (NYT, Dec. 26th). The next frigid wave that gripped most of the US came in early January 1940 (NYT, Jan. 6th). On January 21st, 1940, The New York Times reported: “The cold polar air remained stagnant over vast areas of Europe and North America. Result: Some of the coldest weather in half a century. In Moscow the temperature dropped on Wednesday to 49 degrees below Fahrenheit (1); in parts of Finland to 58 below.” In the US the extreme conditions were over by February 1940, in North Europe they remained until end of March 1940 (ditto, and ). CO2 is defiantly excluded as option.

    As the years before winter 1939/40 and now were the warmest over a period of 500 years, it seems time to understand what caused the polar winter conditions in winter 1939/40. The “driest fall of record” in the US may have contributed significantly. Climate is ruled by physical laws, which do not care for consensus.
    (1) The low temperature forecast for Moscow from, today, 06th to 15 January 2007 is about 30 degrees Fahrenheit. The New York Times on January 9th, 1940 wrote: “ ’31 Below Zero in Russia’, Moscow, Jan.8 (UP) – A record frost today coated Northern and Central Russia, with the thermometer at 31 degrees below Fahrenheit, and impeded normal activity.”

  2. Mike,

    Thanks for stopping by again. I think you’d be well served by reading the IPCC (which does *not* ignore the mid-century cooling) and the reference I offered last time you visited (which shows that your “driest fall on record” reference is wrong).

  3. I’m concerned, John, when we conflate scientists stating something with non-scientists stating something; rather, we should differentiate somehow, such as perhaps x and x¡, where x¡ is non-sceintist’s opinions.

    That is: I read your post as equating x and x¡. The scientific mainstream consensus is not the same as the public mainstream consensus.

    We have a consensus and a consensus¡, which have supporting argumentation values of value and value¡. The ¡ is perhaps slightly negative, giving us a lesser value for the argument¡. Thus, the two are not equal.



  4. The Monthly Weather Review, Vol. 67, 1939, p. 445, states: “From the Rocky Mountains eastwards it was the driest fall of record, considering the area as a whole”. TIME magazine (Dec.1939) was more “generous” in so far. But what about the four decade global cooling? Where did

    “IPCC dealt with this aspect? The closest I could find is the following text (excerpt):
    IPCC, Climate Change 2001: Working Group I: The Scientific Basis,
    1.3.3 Observing Anthropogenic Climate Change
    The 20th century
    Historically, human activities such as deforestation may have had a local or regional impact, but there is no reason to expect any large human influence on the global climate before the 20th century. Observations of the global climate system during the 20th century are therefore of particular importance. Chapter 2 presents evidence that there has been a mean global warming of 0.4 to 0.8°C of the atmosphere at the surface since the late 19th century. Figure 2.1 of Chapter 2 shows that this increase took place in two distinct phases, the first one between 1910 and 1945, and recently since 1976…”

    John, all success with your book on drought, it will be interesting reading.

  5. Mike –

    As I said before, there is a significant body of more recent research that is at odds with your six-decade-old citation.

    As for the IPCC’s discussion of this, I suggest Chapter 12 of the IPCC’s Third Assessment Report.

  6. “Because the IPCC, held to punishingly conservative standards of peer-review and consensus, is silent on the hurricane question … does that mean everyone has to be silent?”

    When you get to this level of stupidity its time to start hurling abuse. What bullshit-artist Roberts is.

    And all of you are facing in exactly the wrong direction here. We are in an ice age for love of stupid people everywhere.

    “What we know now is that 2006 was the warmest of half a dozen years in the last half millennium,…”

    No you are wrong. OK? You got that?

    You are comparing yearly averages to century averages. Or you must be to be getting such a crazy statement like that together.

    This is without a doubt the worst case of Wrong-Way Corriganism and mass-stupidity in the history of science.

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