Tyndall Lecture: GC43I. Successful Predictions (Video On-Demand)

6 Dec 2012 2:40 pm - 3:40 pm

Named Lecture, Video On-Demand

Ticketing Type:
Open to All

Section/Focus Group:
Global Environmental Change (GEC)


Raymond Pierrehumbert
Moscone West - Rooms 2022-2024

Presented by Raymond Pierrehumbert, University of Chicago, Illinois, USA

The scientist selected to present this annual lecture, offers a historical perspective on global environmental change.  The lecture is named in honor of John Tyndall, the physicist whose measurements in the late 1850s and early 1860s verified the importance of the greenhouse effect that had been proposed by Fourier in 1824. This lecture focuses on the development of the science underlying global environmental change and provide a historical perspective.


  1. Cees de Valk says:

    Hi Tamino, so what is my propaganda precisely? That I don’t like scientists mixing up science with politics? You appear to imply something about my political preferences. Well let me get that out of the way for you first: if I were an American, I would have voted Obama this time after weighting all the pro’s and con’s. But that does not matter. I just can’t believe how frivolously many climate researchers mix science with activities like saving planets and politics, as we can see in this video. And I’ve seen many others like that. If scientists assume the roles of politicians and activists, then don’t be surprised that elected politicians start questioning the science. Or is it propaganda that I say that? I think that climate scientists need to take a hard look at what is their professional role in society. There are plenty of other people, politicians, activists, who will be happy to do the politics.

    And hi Paul: I fully agree with you about what the real question is (how much, how fast?), but that is a very big question mark. We need to get to terms with the fact that we have to manage our environment, but that is something different from eliminating our influence (we have it in many different ways whether you like it or not), there is no natural stable state and we know still fairly little about what part nature plays, what part we play and what would be best for us to do. But when you are the supposedly trusted knowledge source and start pushing society in a particular direction, you will loose that trust. AGU and it seems, many of its members, does not seem to get that.

  2. tamino says:

    Great presentation. It really puts the development of climate science in good perspective.

    It’s ironic that commenters like Cees de Valk promote their own propaganda by accusing others of propaganda. In truth, the cautions added by Pierrehumbert at the end are mild compared to what we can expect of a future world, if we don’t take the global warming problem seriously.

  3. Paul Vincelli says:

    All I can say is, if you doubt the quality of the science presented at AGU, come to the meeting and go to the scientific sessions themselves. This was merely an overview lecture. I am a publishing scientist in a discipline outside of the geosciences (so I think I am a pretty unbiased observer), and this was my first AGU meeting. I was highly impressed with the quality of the science overall. Moreover, there were literally thousands of papers and research posters that related in some way to climate change. Yes, thousands. In this week-long, exhausting, intellectually enriching meeting of 22,000 mainstream scientists, I could find no meaningful debate on the fundamentals of climate change: that we are causing a dramatic increase in heat-trapping gases in the atmosphere; that this is rapidly warming Earth (as well as causing ocean acidification); and that this warming poses increasing risks to human health and well-being. To repeat: No meaningful debate at the world’s premier meeting of climate scientists.

    Keep in mind that scientists are disciplined and vigorous skeptics, and yes, there were debates, disagreements, challenges, and pointed questions. But these debates were not about whether humans are causing global warming, but how quickly human-caused warming will proceed, and what the impacts will be on humans and our environment.

    Perhaps the most memorable moment of the meeting was when Dr. Pierrehumbert said to a roomful of hundreds of scientists, “We are conducting an uncontrolled experiment with Earth, and we have to live in the beaker.”

  4. Cees de Valk says:

    I could not belief what I was hearing and seeing. Two-thirds of the speech is just a dull historical review. Then a short superficial review of some more recent climate modelling, and finishing with a mix of religious doom prophesy and unashamed propaganda unsupported by the presented material, and illustrated with a halfway submerged statue of liberty and Obama’s acceptance speech. And you people at AGU call this science? If this is current climate science, it is really not in better shape than social psychology. What I can’t get is this: don’t you see it yourself? Or do you not care? As a citizen, or an elected representative, I would not trust the advice of a scientist who is already with one foot into politics, without having been elected.

    • Michael Tobis says:

      Dr. Pierrehumbert has made many detailed substantive contributions to the science, as the introduction plainly stated. The reader skeptical of his skills is referred thereto: http://geosci.uchicago.edu/~rtp1/papers/publist.html

      The named lectures are intended more as retrospectives than as new results, and a fair-minded person would not object to examining the history of how the understanding of this key question evolved.

      As to whether exhorting the leader of one’s country to address an issue of this importance in such a talk is or is not appropriate, the tradition is to give a certain freedom of expression as a part of the award. If an accomplished scientist cannot speak of the social import of the topic they are discussing at such an event, what possible venue could there be?

      Your recommendation would have carried some weight some years ago. Indeed, until the persistent and malicious libels of the past few years such an argument in fact did dominate the field. But climate scientists are no longer willing to be passive players while their reputations as well as their results are smeared. It falls to those actually best acquainted with the science to stand up for it.

      A fair-minded listener would take this talk as a broad tour of the intellectual underpinnings of the concern. That it leads to a plea to the political leadership to take the matter as seriously as the evidence demands is hardly unprecedented in a scientific setting, and it certainly does not undermine the substantial aspects of the story.

      Finally, I for one can’t imagine why a historical review like this should be considered dull.

    • Eli Rabett says:

      Mr. de Valk has had a useful reply from Paul Vincelli, but there is an important issue he raises at the end, and the answer to that question marked an important shift in this year’s AGU conference (btw, although it is the American Geophysical Union Conference, a substantial part of the membership and attendees are from other lands).

      In the past many AGU members tried to avoid controversy, they knew the implications of their science required changes in policy by our governments but were not willing to expose themselves to the like of Mr. de Valk. They were not willing to call out the few amongst them (and it really is only a few) who were, for whatever reasons, denouncing the clear scientific consensus about the dangers of man made climate change.

      This is no longer the case. Prof.Pierrehumbert’s Tyndall lecture was an important step making clear the consensus of climate scientists about the dangerous future that awaits us if our fellow citizens and their elected representatives do not pay heed. Scientists, as much as Mr. de Valk may regret it, do live in the world and must avoid Martin Niemoller’s mistake if the world is not to suffer.