To Limit Choice or Expand Choice?

September 26th, 2006

Posted by: Roger Pielke, Jr.

In a paper out yesterday, NASA’s Jim Hansen recognizes the difference between a scientist serving as an issue advocate versus as an honest broker of policy alternatives when he writes (PDF):

Inference of imminent dangerous climate change may stimulate discussion of “engineering fixes” to reduce global warming. The notion of such a “fix” is itself dangerous if it diminishes efforts to reduce CO2 emissions, yet it also would be irresponsible not to consider all ways to minimize climate change.

So which is it? Dangerous or irresponsible? Should scientists openly discuss all ways to minimize climate change, including little-mentioned technologies like air capture? Or should scientists seek to limit research agendas in order to take some options off the table and privledge others in political debate?

It can’t be both ways at the same time. Should scientists seek to limit choice or expand choice?

11 Responses to “To Limit Choice or Expand Choice?”

  1. bob koepp Says:

    Roger – I don’t think that scientists, qua scientists, should _seek_ either to limit or expand choice. Qua scientists, they should _seek_ to present the most reliable information they can assemble relevant to the problems at hand. If that information has the effect of either limiting or expanding the available “reasonable” alternatives, so be it.

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  3. Roger Pielke, Jr. Says:

    Bob- Thanks. But in practice, scientists, science managers, science institutions, and science funders all face choices with implications for the scope of choice available to decision makers. Hansen provides a good example.

    Of course the most relevant information to the problem at hand is: what are our options and what are their likely consequences?


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  5. Nosmo Says:

    Why can’t it be both?
    If the danger is imminent then perhaps we do need to consider technological fixes, but not to recognize the possible negative consequences of such an approach is irresponsible.

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  7. Steve Hemphill Says:

    Bob -

    You have touched on what I think may be the most important question concerning AGW. You say “Qua scientists, they should _seek_ to present the most reliable information they can assemble relevant to the problems at hand.” That is, I disagree with your simplistic evaluation borne of the laboratory. The amplifier is the “penalty for failure.”

    Ponder that. Please.

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  9. bob koepp Says:

    The reason I framed my comment so formally, in terms of what a scientist qua scientist should do, is because there’s an ambiguity in your orignial question. Obviously, scientists are asked to opine on non-scientific matters where their scientific expertise is relevant. But as soon as they venture opinions which are not a matter of science per se, they assume the role of informed citizens — at which point we should _expect_ them to give expression to the non-scientific values and biases that go into making complete persons.

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  11. LDilling Says:

    Hansen has done a good job in the past on bringing up various options, as this paper does, e.g. his past work on methane and black carbon (examining whether focusing on these species might be easier “low-hanging fruit” for mitigation than CO2 at first). He does say in the second to last sentence of the paper that geoengineering should be investigated. But he also says that considering the geoengineering option is dangerous because of the different time scale of aerosols in the atmosphere vs. CO2– his last sentence– CO2 lasts centuries and so would likely still require direct mitigation. Personally I think scientists have a responsibility to point out the options and their consequences. But scientists also have a right to consider some options “dangerous” and express their reasons and opinions for that view. A similar debate has occurred in the ocean iron fertilization arena.

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  13. Steve Hemphill Says:

    Lisa -

    You quote:
    “CO2 lasts centuries”

    I presume you understand the exponential concept of half-life and question whether you disagree with Peter Dietze’s calculations that the half life of CO2 in the atmosphere is less than 40 years, and if so on what basis.

    5 half lives would be “centuries.” Is that what you’re talking about?

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  15. Lab Lemming Says:

    A harvard study suggests 19-97 years, based on biological uptake (and presumably sequestration):…8…23M

    As for Mr. Dietze:
    I’m a chemist, not an oceanographic modeller, but I’d suggest taking a close read of Brian O’Neill and Tom Wigley’s responces for very patient discussions of this model. Note also, that Peter Dietze replies by dismissing problems regarding ocean mixing qualitatively, without first demonstrating understanding of those problems at a quantitative level.

    It is human nature to put less trust in a constraint which you don’t understand. We all do it, both in science and in everyday life. But it is not good scientific practice. At the risk of sounding like an arrogant twat (too late), one of the useful things about formal science training in the form of a PhD is that, a couple of year in, you get tested on your knowledge of the field in which you are researching. This is called a mid-term review down here- not sure the American name (pre-lims), but the purpose is twofold:

    1. Demonstrate the ability to do research.
    2. Demonstrate the knowledge of the field necessary to correctly interperet those results.

    One of the problems in the science/education or science/policy field is that word correct. To an outsider, this looks like imposed adherence to a particular outcome or belief: e.g. politically correct. What we’re trying to say by correct is more related to how the problem is addressed and incorporated into the existing body of knowledge, rather than what the outcome is.

    I’m currently blogging about this issue- I had an analysis last month that appeared to contradict the Big Bang, and I’m going to finish posting next week about the interpretation process. I’m still doing the math for that post, though, so it will be a while.

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  17. Judith Curry Says:


    I think you have framed the issue ambiguously, sort of in a “why are you beating your wife” manner. Scientists should work to expand the options, but they should be very careful if they decide to advocate politically for their own option. Whatever policies that are eventually adopted will have to pass tests of technical, economic, and political viability. Once a policy or strategy passes some sort of political and economic test, then scientists can work to assess the likely impacts (both desirable and unanticipated) of the proposed strategy. Scientists do get asked by the media and policy makers “what should we do about this?” The answer that I have come up with personally:

    “There are numerous ideas on the table for addressing the global warming problem, including adaptation, reduction of carbon dioxide emissions, and sequestration of carbon dioxide. Most likely, a combination of all three strategies will be required to address both the short term and long term effects of global warming. It is time to start a serious dialogue in this country on how best to develop policy and technological options to address the challenges of global warming that are practically feasible, cost effective, and politically viable.”

    This sort of ducks the issue of advocating for specific policies, but says we need to do “something”

    Many scientists conducting climate research, without any great understanding of mitigation technologies, economics or politics, were naturally drawn to Kyoto Protocol that would (in principle) reduce CO2 from the atmosphere by limiting emissions. The Kyoto Protocol has been criticized for many reasons, but at the end of the day it did not pass the test of political viability in the U.S. Leaping straight to a policy recommendation, without doing the economics homework and impact assessment leads to policy gridlock (which is what we have in the U.S. right now).

    Scientists that want to influence policy and engage in the policy process will be far more effective in the long run if they do not advocate for specific policy options too early in the process, at least before the broad environmental and economic impacts of the policy have been studied in a significant way. This is not an easy path for a research scientist to navigate, and it is far easier to engage with advocacy groups and talk to the media than it is to actualy do the hard work of assessing the environmental and economic impacts of proposed strategies. And it is even easier to stay out of the whole process and just publish scientific papers and stay out of the public and policy debate.

    Roger, here is a challenge for your blog: ideas for a roadmap for (climate) scientists to engage in the policy process. I’m sure you will refer me to tons of academic papers on the subject, but something more practical is needed for the individual scientists as well as the institutions they work in and the agencies that fund them

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  19. Roger Pielke, Jr. Says:



    You write: “Roger, here is a challenge for your blog: ideas for a roadmap for (climate) scientists to engage in the policy process. I’m sure you will refer me to tons of academic papers on the subject, but something more practical is needed for the individual scientists as well as the institutions they work in and the agencies that fund them.”

    Well, I could not have asked for a better description of the purpose of my forthcoming book! It may or may not succeed in its task, but it is precisely this thinking that is behind it. It is coming out in the spring. I’ll be promoting it here leading up to it. You can let me know how well it succeeds . . .


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  21. Steve Gaalema Says:

    >Should scientists openly discuss all ways to minimize climate change..?

    Since the alternative is either only secret discussion of some ideas or limiting allowed ideas, the answer should be obvious. How can someone suppress understanding of a problem and call themselves a scientist?

    I suppose knowledge of how to produce biological weapons might be an exception, but that appears to me a totally different situation (although some may disagree…)