Please Critique this Sentence

June 20th, 2006

Posted by: Roger Pielke, Jr.

I am working on a new essay on climate policy. I would like your help by critiquing the following sentence, with a particular focus on providing any counter-references from the peer-reviewed literature.

No emissions reduction policy currently under discussion – from changes in personal behavior to those proposed under the Framework Convention on Climate Change – even if successfully implemented will have a discernible effect on the global climate system for at least 50 years.

Now, let me say that this statement, which I believe is scientifically accurate (e.g., see NCAR’s Jim Hurrell testimony) does not mean that we should throw up our hands or stick our heads on the sand about greenhouse gas emissions. But this sentence does have profound implications for thinking about climate policies, their public justifications, and the significance of adaptation. Such implications are typically not front and center in the climate debate, but they should be.

47 Responses to “Please Critique this Sentence”

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  1. David Bruggeman Says:

    Roger,

    A critique of the word order.

    You have two asides back to back. The sentence should read better if you move “even if successfully implemented” to the end of the sentence, probably set off by a comma.

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  3. William Connolley Says:

    Probably begs the question of “under discussion by who?” (whom?). There certainly are various policies for substantial emissions reductions advanced by, e.g. the Green Party, which would have an effect [http://www.greenparty.org.uk/files/reports/2005/Climate%20change%20J.htm]. Even Labour endorse 60% cuts by 2050, which would again have a discernable effect. OR are you thinking of only US discussions?

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  5. Chris Weaver Says:

    Hi Roger – do you clarify in the essay what you mean by “under discussion?”

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  7. Andrew Dessler Says:

    Roger-

    While I agree that your statement is factually accurate, I would argue that it misleads. Consider the following statement that I think better articulates the situation:

    Because of lags in the climate system, the climate of the next few decades has already been determined by prior emissions. Emissions reductions currently being discussed will therefore have an effect primarily on the climate in the 2nd half of the 21st century.

    I think this statement is less amenable to misinterpretation (wilful or not).

    Regards.

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  9. Kit Stolz Says:

    I too think it misleads, because it takes for granted the mostly benign nature of our climate today. Emissions reductions are designed to protect that climactic loveliness; obviously, they can’t improve on it. But we as a carbon-emitting species are capable of making matters dramatically worse before 2050, and that sentence trivializes that possibility.

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  11. Clyde Soles Says:

    Who is the audience for this essay? The sentence isn’t specific enough for the GW literati. Yet it’s too geekish for the general public.

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  13. Jim Lebeau Says:

    I like your statement better than Andrew’s statement. Your statement does not imply a guarantee that the reductions will have an effect.

    OTOH you are trying to cram a great deal into one sentence.

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  15. Roger Pielke, Jr. Says:

    David- Thanks!

    Chris- I am trying to say something along the lines of “any policy cureently being proposed or implemented” — the point being that there is nothing even under consideration that can have a discernible effect on the climate. It may be better to simply say “no emissions reductions policy” … as this would be accurate also, I believe.

    Andrew- Yes, the reasons why are important, but will likely be what follows this sentence. E.g., “There are X reasons for the long lag between emissions reductions and discernible effects on climate …” Another important factor (related to Chris’ question) worth mentioning is that the policies currently being discussed, Kyoto, post-Kyoto, McCain/Lieberman, etc. etc. are really just drops in the bucket.

    Also, I have gone back-and-forth on “discernible” vs. “perceptible” because scientists might be able to discern aggressive emissions reductions policies in the growth of CO2 in 50 years, but such a change would not lead to perceptible changes in the climate itself. Thoughts?

    Thanks!

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  17. Roger Pielke, Jr. Says:

    William- Thanks, but I doubt that a cut in UK emissions by 60% would have a discernible effect on climate. WOuldn’t you agree?

    Kit- The sentence is scientifically accurate.

    Clyde- Yes, this is always the challenge. Not the public, but the decision making elite.

    Jim- Yes, perhaps simplification by breaking up is an option.

    Thanks!!

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  19. LDilling Says:

    Depends what you mean by ‘policy currently under discussion’. Pacala and Socolow (Science 2004) discuss a variety of options each of which could significantly reduce emissions in the next 50 years and have a discernable effect on climate. I don’t know if this counts in your argument as “policy under discussion” since they are not specific governmental policies. If your sentence is just about Kyoto or policies that are actually being considered by governments individually, yes, that’s accurate I think. But some policies currently in effect do set targets of emissions reductions by 60-80% by some decade in the future, which, if they were achieved, I think is more than a drop in the bucket- it’s just that these would need to be worldwide and aren’t currently. Another thing to keep in mind (your reply to Andrew) which I know you know very well is that the lag time is not just in the climate system, our infrastructure has lag times of 30-50 years (time frame of power plants, transportation systems, dams, etc.). So of course policies would need to be in place for several decades before we would expect to see a change in the atmosphere- infrastructure doesn’t turn over very fast. If we are concerned about high concentrations of CO2 in the atmosphere by the end of the century, this argues to me for policy agreement sooner rather than later, so that changes in infrastructure (for either adaptation or mitigation) can be made in a cost-effective manner.

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  21. Roger Pielke, Jr. Says:

    Lisa-

    I don’t think that Pacala and Socolow suggest that their wedges would have a discernible effct on climate in tghe next fifty years. It would be interesting to ascertain when a reduction of 80% over the the next fifty year would have a discernible effect.

    And no, what they recommend are not really policies, but aspirations that do not consider politics, costs, or any other messy realities. I could invent a bunch of “wedges” to get rid of world pverty, hunger and income disaprity in theory! Getting it done is always the hang up!

    Thanks!

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  23. Mark Bahner Says:

    What a mess. I forgot to sign in…and didn’t copy my comments.

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  25. Mark Bahner Says:

    Reconstructing my comments (and adding a bit):

    1) Without any government intervention of any type, I predict a “50% probability” value of 477 ppm in 2050:

    http://markbahner.typepad.com/random_thoughts/2006/04/complete_set_of.html.

    2) With a *worldwide* linear decrease in emissions of 60% by 2050, the concentration would be 410-415 ppm.

    3) The difference is approximately 65 ppm. That might make a temperature difference of approximately 0.2 to 0.3 degrees Celsius.

    4) With a linear decrease in emissions only in the U.S. (and Britain) of 60% by 2050, the concentration would be about 465 ppm in 2050 (versus 477 ppm for “do nothing”). That would make essentially no difference in temperature (less than 0.1 degree Celsius).

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  27. William Connolley Says:

    Roger – an odd response from you. UK by 60%, no. The same done globally, obviously yes.

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  29. Paul Biggs Says:

    I’m far from convinced that climate can be predictably controlled or influenced by the attempted manipulation of a single factor.

    Something else might have a big influence on climate in less than 50 years:

    http://science.nasa.gov/headlines/y2006/10may_longrange.htm?list3134

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  31. Roger Pielke, Jr. Says:

    William-

    That is odd that you think my response odd;-)

    Two replies:

    1. I believe that the world should cut poverty by 60% over the next 50 years. Is this a policy? Is this a policy proposal? In my field, where such things are discusses in arcane technical detail, such a statement is not technically a policy, but a statement of goals or aspirations. The difference matters. Other critieria that should be applied to determining the difference is authority, control, resources, feasibility, etc. Clearly, I have none of these in my poverty statement.

    2. But lets just assume that the UN FCCC adopted a global policy focused on 60% reduction below todays levels by 2050. I am curious how the climate system would be perceptibly different in 2056 versus a world in which (a) business as usual (pick your scenario), (b) no change from 2006 emissions, (c) a 10% decrease from 2006. My understanding of the science, and please correct/point to literature if this is incorrect, is that 50 years is simply too short to be able to differentiate climate outcomes among these scenarios.

    Thanks!

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  33. Roger Pielke, Jr. Says:

    William-

    I should add, please pick your variable, e.g.,:

    1) Global average temperature (maybe discernible but definately not perceptible)

    2) Sea level rise (maybe discernible but definately not perceptible)

    3) Hurricanes (!) or other extremes

    4) Ice sheet behavior

    5) Whatever

    Thanks!

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  35. Mark Bahner Says:

    Hi Roger,

    Ah, a nice complicated analysis! I’ll give my answers to your questions, starting with temperature:

    a) Versus business-as-usual, the reduction in temperature for a 60% (linear) decrease in CO2 emissions would be about 0.2-0.3 degrees Celsius…probably closer to the lower value. See my previous comments.

    b) Versus no change from 2006 emissions, the difference would be about 0.1-0.2 degrees Celsius.

    c) Versus a (linear) reduction of 10% from 2006, the difference would be about 0.1 degree Celsius.

    As noted by Paul Biggs, these differences could easily be swallowed up by a change such as a substantial reduction in the sun’s strength.

    For example, I’m predicting that reducing worldwide emissions by 60% from their current level, versus “business as usual,” would mean a reduction in temperature by 2056 of 0.2 to 0.3 degrees Celsius. In other words, I’d expect about 0.6 degrees Celsius temperature rise from now to 2056 under “business as usual,” but only a 0.3 to 0.4 degrees Celsius (and proably closer to 0.4 degrees Celsius) rise if worldwide CO2 emissions can be reduced by 60% from current levels over that time.

    But it could easily be that, under “business as usual,” the temperature rise would only be 0.3 to 0.4 degrees Celsius, if the sun got weaker and stayed that way through 2056.

    The sea level rise would be about 6 inches under all those scenarios.

    Hurricanes…well that depends how wrong current hurricane models are. If they are essentially correct, there would be no difference. If they are way off, there might be a discernable difference. But the difference would be completely eliminated…in fact, there would be a *reduction* in hurricane strength…if hurricane reduction methods can be developed by 2056. (And I don’t see why they can’t be developed by that time.)

    Ice sheets: No difference. (In fact, ice sheet behavior is likely to be much more influenced if there is a substantial decline in black carbon emissions, which will almost certainly happen even if CO2 emissions increase.)

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  37. Kit Stolz Says:

    Roger:

    Let me express my appreciation for your openness to discussion.

    But although I don’t question that the one sentence is scientifically accurate, I still think it fails to tell the whole truth.

    Let me put it this way: Are you also going to assess the risks of a business-as-usual course re: emissions?

    Thanks!

    KS

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  39. Gavin Says:

    Despite what Andrew or others think, I think that the sentence is actually wrong. If you turn it around and ask whether the trajectory of GHG emissions is irrelevent to global mean temperatures in 50 years time, then it is obvious it is a statement about timescales of climate response to changing emissions, not about the effectiveness of any particular policy action at changing GHG concentrations. The relevant timescales for climate response to concentration changes is a couple of decades, the time scale for a change in emissions to significantly alter concentrations is also a couple of decades, and so the effect of changes in emissions is likely to be seen before the 50 years are up. As an example you can look at the results of climate models run with different emission pathways (both for SRES (no mitigation) scenarios and Hansen’s ‘Alternative’ scenario (AS) (assuming mitigation). Figure 19a in Hansen et al (submitted) (available at http://pubs.giss.nasa.gov/abstracts/submitted/Hansen_etal_1.html ) shows that the differences between SRES and AS in global mean temperatures are noticeable by 2030 and very significant by 2050. If actions are taken to move the world away from anything resembling A2 or A1B and move it towards the AS, then that will indeed be noticeable.

    A second point is alluded to above; efforts that aim to control CH4, CFCs, trop O3 or black carbon have much shorter concentration response times and so will impact climate all the faster if changed. Your statement applied to them is even more flawed.

    So while your statement might be a fun strawman to erect for the sake of argument, it likely does not reflect reality. I would therefore be hesitiant in using it as the basis of any substantial discussion.

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  41. Roger Pielke, Jr. Says:

    Gavin-

    Thanks, but i think that you are conflating scenarios with policies. We can all invent fanciful scenarios and plug them into models. But scenarios are not policies or even policy proposals, and I am aware of no policy proposal being discussed that comes close to your AS.

    You write, “If actions are taken to move the world away from anything resembling A2 or A1B and move it towards the AS, then that will indeed be noticeable.”

    My question for you is what sized “move” in accumulated emissions reduced is necessary in order to be discernible (“noticable”) in your model by 2050 (in terms of emissions)? Lets stick with global average temperature (GAT) to make it easy, and a statistical significace of 95%. And what effect with such a change in GAT have on, say, sea level rise?

    I look forward to your answer!

    Thanks!

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  43. Roger Pielke, Jr. Says:

    Kit-

    Thanks.

    Assessments of the likely consequences of BAU are readily available from more qualified experts than me, e.g., IPCC. The question I want to get at is what are the climatic effects of deviating from BAU over the next 50 years, based on actual policies currently being discussed. This seems to be a completely neglected subject, as far as I can tell.

    So I look forward to Gavin’s response.

    Thanks!

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  45. Mark Bahner Says:

    Roger,

    You write, ” We can all invent fanciful scenarios and plug them into models. But scenarios are not policies or even policy proposals,…”

    That’s absolutely right. The IPCC invents fanciful “scenarios” that result in “projected” temperature increases from 1990 to 2100 of 1.4 to 5.8 degrees Celsius.

    But what they don’t admit is that the chances of warming of about 1.4 degrees Celsius are about 50/50. And the chance of warming of even the MEAN value of 3.6 degrees Celsius are infintesimally small (less than 1 percent).

    You continue, “…and I am aware of no policy proposal being discussed that comes close to your AS (Alternative Scenario).”

    That’s where you’re wrong. I think you’re neglecting the importance of methane as a GHG…and the outrageous over-”projection” of methane atmospheric concentrations in the IPCC TAR.

    Take a look at slide 43 of James Hansen’s AGU presentation:

    http://www.columbia.edu/~jeh1/keeling_talk_and_slides.pdf

    Notice how the methane concentration increases (i.e., the figure labeled (“delta CH4, ppb/year”) are actually BELOW James Hansen’s Alternative Scenario (the dark red straight line). And the B1 and A1B methane concentration increases are laughably falsely high.

    In fact, look at the final, money figure:
    “Forcing Growth Rates, W/m2/year.”

    Which scenario are the actual forcing growth rates closest to?

    Mark

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  47. Gavin Says:

    Roger, you are better off doing those kinds of calculations yourself using a simpler model (like Tom Wigley’s MAGICC) – a GCM can’t provide the number of tests necessary for the answers you want. If you want more details on what would be required for us to be on an AS course, I suggest you read some of Hansen’s many papers on the topic. Basically it’s a slowing down of the CO2 rate of growth, and absolute declines in CH4 and CFCs. However, the changes are not so massive as to be unthinkable, and the temperature change by 2050 is highly significant. Therefore, significant efforts that fall short of AS will also make a difference – but you need to do the calculations to see what the minimum reduction would be.

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  49. Roger Pielke, Jr. Says:

    Gavin-

    Thanks. This sort of calculation is exactly what is needed. I am amazed that it has not been done. (If it has, some one point me to it!)

    But consider this, your paper with Hansen states, “Continued rapid growth of CO2 emissions for another decade, along with the infrastructure producing the emissions, would make achievement of the alternative scenario impractical if not impossible.”

    Then I read this: “In the IEO2006 reference case, world carbon dioxide emissions increase from 25,028 million metric tons in 2003 to 33,663 million metric tons in 2015 and 43,676 million metric tons in 2030.”
    http://www.eia.doe.gov/oiaf/ieo/emissions.html

    In short, at some point scenarios must meet the realities of policy and practicality. It is the scenario that is a straw man for the sake of argument.

    Thus, I stand by my sentence: “No emissions reduction policy currently under discussion – from changes in personal behavior to those proposed under the Framework Convention on Climate Change – even if successfully implemented will have a discernible effect on the global climate system for at least 50 years.”

    If you want to counter this, you need to provide a policy, not a abstract scenario. Thanks!

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  51. Paul Biggs Says:

    Of course, Roger Pielke Senior would argue that land use changes are at least as important a human influence as CO2. There are plenty of peer reviewed publications out there to support such a view. Again, the question is can man control the climate, predictably or otherwise, with a single climate factor out of the many, both known and unknown?

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  53. Tom Rees Says:

    The implication (of your paragraph) being presumably that it highlights the lags in climate response, which supports the idea that small actions taken soon are as effective as large actions taken later. Does the global commons institute proposal count as a policy proposal? http://www.gci.org.uk/ Not sure from your definition. Otherwise, there is no agreed policy that I know of that looks beyond 2012 (i.e. Kyoto), so obviously none that will impact climate in 2050. As an aside, remember also that climate monitoring will be more intensive in the next decades, and understanding greater, and so discerning an effect will be easier than hitherto.

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  55. Kit Stolz Says:

    To return to my favorite language, English, the mention of 2050 sparked a memory of a quote from Lonnie Thompson on the topic cited in a book published in January of this year:

    “Scientists are by training and nature conservative and…have probably underestimated our impact. Fifty years from now—I hope I’m wrong—I think you may be living in a world where you don’t go outside between one and four in the afternoon.”

    http://www.nybooks.com/articles/18616

    It may be true that we as a species will not be able to discern or perceive the effect of emissions reductions measures within fifty years.

    But that doesn’t mean the climate isn’t changing. And although the captain of the Titanic couldn’t perceive the iceberg, that doesn’t mean he shouldn’t have changed his course.

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  57. Roger Pielke, Jr. Says:

    Tom, Kit- Thanks. The point here is not whether we should act, but how we should act, and how we should justify such actions in ways that lead to actual effective implementation.

    The C&C proposal is interesting, but as yet an academic exercise. Perhaps one criteria we can use to discern a “policy” is whether the action is being discussed by policy makers. Current discussion of climate policy is either misguided (because it doesn’t include the long term) or faith-based (because it assumes that future decisions will be made following otday’s inconsequential efforts).

    Thanks!

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  59. Tom Rees Says:

    Roger, you’re equating whether or not a policy is ‘consequential’ with whether it has a ‘discernable effect on climate’. The two are not necessarily the same. For instance, Kyoto will likely have no discernable effect on climate. But it will have (and has had) discernable effects that have consequences for future climate (stimulating technology, setting up nascent carbon trading).

    Put it another way. Policy decisions are likely to have a 10-20 year time frame, because that’s the way the world works. Therefore, no single international agreement is ever going to have a discernable effect on climate – because the lags (technological and economic, as well as climate lags and climate variability) are too great. However, a sequence of policy decisions could well have.

    In other words, I think you are defining ‘proposed policy’ in such a way that policies that fit your definition can never have a discernable effect on climate. However, a series of such policies could have.

    As another aside, Kyoto even seems to have positive effects for adaptation, depsite your conceptions. In the UK, there are many active plans to adapt to future climate change (e.g. the Future Flooding Initiative). In the US, on the other hand, I didn’t see any reference to future climate change in the decisions to, e.g. rebuild New Orleans. I think that the difference in attitudes is a by-product of Kyoto. To put it crudelly, you get adaptation where there is ‘alarmism’, but not ‘denial’ (I know, I know, the polls showing that the US public is not in denial, but the proof is in the pudding).

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  61. Roger Pielke, Jr. Says:

    Tom-

    Thanks for these further comments. I did write above in the comments:

    “I have gone back-and-forth on “discernible” vs. “perceptible” because scientists might be able to discern aggressive emissions reductions policies in the growth of CO2 in 50 years, but such a change would not lead to perceptible changes in the climate itself.”

    I am leaning to perceptible, though consequential is worth thinking about as well.

    I agree about your point on “sequence of policy decisions” but what sequence are you referring to? Right now such a sequence is faith-based, and not grounded in any actual policy discussions. To strech an analogy, George Bush may believe that a “sequence of policies” will lead to democracy and peace in Iraq decades hence, but I prefer to evaluate policies as they are presented rather than accept some undefined promises about the future.

    Finally, I disagree about Kyoto and adatpation. While talk of climate change may focus some attention on adaptation in rich countries, the FCCC has a strong bias against adaptation generally, as I’ve discussed before.

    Thanks!

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  63. Mark Bahner Says:

    Hi Roger,

    I don’t know if you saw my question…

    On slide 43 of James Hansen’s AGU presentation:

    http://www.columbia.edu/~jeh1/keeling_talk_and_slides.pdf

    …there is a figure labeled:

    “Forcing Growth Rates, W/m2/year.”

    Which of the scenarios presented do you think most closely represents the actual climate forcing rates to date (shown as the solid curves)?

    Thanks,
    Mark

    P.S. Gavin, what is your opinion? Which of the scenarios presented do you (and/or James Hansen) think most closely represents the actual climate forcing rates to date?

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  65. Roger Pielke, Jr. Says:

    Mark- I saw it but thought you were joking, since we discussed this ad nausem a few eeks ago:-)

    http://sciencepolicy.colorado.edu/prometheus/archives/climate_change/000838scenarios_scenarios.html

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  67. Mark Bahner Says:

    Hi Roger,

    No, we did not discuss the answer to my question ad nauseum a few weeks ago.

    Why can’t you give a simple answer to a simple question?

    Here are the scenarios in that figure 43:

    1) “Alternative Scenario” (aka, “AS”…which results in 1 degree Celsius temperature rise)

    2) “B1″ (IPCC TAR scenario B1)

    3) “2 deg C.” (self-explanatory)

    4) “A1B” (IPCC TAR scenario A1B)

    5) “A1F1″ (IPCC TAR scenario A1F1)

    Which of those 5 identified scenarios most closely represents the actual climate forcing to date, in the figure labeled “Forcing Growth Rates, W/m2/year.”

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  69. Roger Pielke, Jr. Says:

    Mark- Hansen’s graph has observations on it, so I’m not sure what you are looking for beyond that. And for the last time, yes, I did hold a lengthy discussion in several posts here, which spread to several other weblogs, on Hansen’s various scenarios. If you don’t wish to read them — bottom line: Hansen’s scenarios have connsitently overestimated emissions (and forcings). I do not however wish to revisit this subject on this thread. Thanks!

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  71. Mark Bahner Says:

    Oh, brother.

    My lunch period is over. All I’m trying to do is point you to the direction that you’ll correct your own false statement (to Gavin Schmidt) that:

    “…I am aware of no policy proposal being discussed that comes close to your AS.”

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  73. Chris Weaver Says:

    Hi Roger,

    I feel like we’re glossing over the “single policy action” vs. “sequence of policy actions” question a little too quickly. I agree with Tom that a sequence of incremental steps could be effective, as likely do you. Is your disagreement with Tom that it matters whether or not you’ve explicitly planned out all the steps in advance before executing the first one?

    I think many people have a sort of short-cut thought about Kyoto that goes something like, “Sure a few percent emission cut won’t have any effect on climate by itself, but it will create an international baseline of good faith from which to move forward to the next step (as well as create at least some market for additional technologies and trading mechanisms).” So, for people who think that we should be limiting emissions at some point, and sooner rather than later is better, then going ahead with Kyoto is a pretty robust option even without knowing what comes next. “Something” will be coming next, and designing and implementing that something will be easier with Kyoto in place.

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  75. Mark Bahner Says:

    Hi Roger,

    I apologize for the tone of my last remarks, but I really have what I think is a quite simple question, for which I think you ought to be able to give a quite simple (one word) answer, without much effort at all on your part.

    You wrote, “Hansen’s graph has observations on it, so I’m not sure what you are looking for beyond that.”

    What I’m looking for is a one-word answer to my question. Please look at slide 43 (page 57 of 64) of James Hansen’s Keeling Lecture:

    http://www.columbia.edu/~jeh1/keeling_talk_and_slides.pdf

    Now, please look at the figure in the bottom right-hand corner of that page, titled, “Forcing Growth Rates, W/m2/year.”

    There are 5 labeled scenarios on that figure:

    1) “Alternative Scenario,”
    2) “B1″,
    3) “2 deg C”,
    4) “A1B,”
    5) “A1F1″.

    Which one of those 5 scenarios do you think comes closest to the actual climate forcings observed to date (the solid curves)? Your answer can simply be one word, e.g.,

    “A1F1.”

    Thanks,
    Mark

    P.S. Of course, if your answer **is** “A1F1,” I’ll be contacting you (confidentially) to ask about getting some of that great stuff you’re smoking! ;-)

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  77. Roger Pielke, Jr. Says:

    Chris- Thanks.

    You well described what I would call “faith-based policy”;-)

    Given the performance of Kyoto, is it really a good idea to assume that “something” will come next? What?

    If we (as a globe) are having this much trouble with Kyoto, how can we think anything is coming next?

    Perhaps I should cahnge the sentence as follows (OK tongue in cheek, but still!;-):

    “No emissions reduction policy currently under discussion – from changes in personal behavior to those proposed under the Framework Convention on Climate Change – will have a discernible effect on the global climate system for at least 50 years, but something is bound to come up.”

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  79. Tom Rees Says:

    Roger, are you saying that the only policy worth discussing is one that commits governments to a fixed approach for the next 50 years plus? I don’t think that’s a reasonable way to proceed. The uncertainties demand more flexibility.

    How about this as a policy: We look at the evidence now. We take a decision based on that evidence, looking forward to the next 100 years but only specifically committing to actions over the next 15. Then, after 15 years, we revise the commitment in the light of new knowledge. I think that’s a good policy (in fact, it’s the one agreed upon), yet not one of the interim policy commitments will, on its own, have a discernable/meaningful effect on climate.

    (BTW, regarding your point on adaptation, I know your views. But it’s ironic that adaptation is a feature of life in Kyoto signatory nations but not in non-signatory. “Impossible” but true. The reasons, of course, are psychosocial rather than legal. The question is to what extent the process of advocating mitigation impacts psychosocial factors thereby creating an environment that also fosters adaptation).

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  81. Roger Pielke, Jr. Says:

    Tom- Thanks. A few replies.

    1. You write: “Roger, are you saying that the only policy worth discussing is one that commits governments to a fixed approach for the next 50 years plus.” No, of course not.

    2. You write: “We look at the evidence now. We take a decision based on that evidence, looking forward to the next 100 years but only specifically committing to actions over the next 15.”

    Sounds good, though we could quibble over the number 15, but as a frmaework, it is great.

    3. You write: “in fact, it’s the one agreed upon” — By whom? To do what?

    Kyoto did not have any discussion of future commitments. It is failing on its own terms. Discussions about post-Kyoto are in gridlock.

    4. You write: “adaptation is a feature of life in Kyoto signatory nations but not in non-signatory.” Well maybe semantic, but non-Kyoto countries have an awful lot of climate adaptation efforts going on. It is a way of life. The issues are less “psychosocial” in my view than economic. The big question is how to create mechanisms to transfer wealth, knowledge, know-how, capacity, lessons, etc. from well-adapted to vulnerable communities in developed and developing contexts. I’ll stand by my assertion that the FCCC is an obstacle in this process, despite “adaptation” efforts under it.

    Thanks!

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  83. Mark Bahner Says:

    Roger,

    It’s now been more than 12 hours since I last asked my very simple question, that has a very simple one-word answer, and which should take you less than 5 minutes to answer. You haven’t answered…even though you’ve found time to comment to multiple times on the “hockey stick.”

    I’ve got to admit that I’m very disappointed. It seems to me that there are two possible reasons for you to write this new essay you’re apparently writing:

    a) you want people to follow the policy recommendations that I presume you’re making, but only because you’re telling the truth about the current situation, or

    b) you want people to follow the policy recommendations that I presume you’re making, even if you are not telling the truth about the current situation.

    Based on the evidence of your lack of reply–again, all I asked for is a one-word reply, that would take less than 5 minutes of your time–it seems to me that the reason you’re writing the essay must be “b.” That is, you want people to do what you recommend, even if you are not telling the truth about the current situation. That’s very disappointing; I thought much more of you than that.

    FYI…the answer I was expecting was “Alternative Scenario.” That is, the “Alternative Scenario”–the one resulting in 1 degree Celsius warming in the 21st century–is the scenario from the graph that most closely represents the climatic forcing to date.

    If you think the correct answer is *not* “Alternative Scenario,” please let me know. I DO care whether whether or not I’m telling the truth about the current situation.

    Sincerely,
    Mark Bahner

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  85. Roger Pielke, Jr. Says:

    Mark-

    Thanks, but you are asking me if I can read a graph. The answer is yes. For the upteenth time, we discussed Hansen’s scenarios at length and documented this a few weeks ago. Yes, to date the emissions path has followed what Jh now calls his AS. As far as predicting the future, I’m not convinced that the IPCC has covered the full range of possibilities, nor Hansen, you, or anyone else. There is uncertainty about the future, there is no single “truth.” Hope this is what you are looking for. Thanks.

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  87. Paul Dougherty Says:

    Roger,
    Your statement seems to me to be accurate for the simple reason that all real policy discussions and actions center around carbon dioxide. Because we have maintained this focus we end up with the simple-minded villain, CO2, and the simple-minded hero, Kyota inhabiting the pop press and the zeitgeist.

    But your statement could be made irrelevant if we faced reality. Gavin states above, “A second point is alluded to above; efforts that aim to control CH4, CFCs, trop O3 or black carbon have much shorter concentration response times and so will impact climate all the faster if changed. Your statement applied to them is even more flawed.”
    No policy or proposal that I am aware of addresses these factors. If so, then Gavin is wrong in saying that ‘your statement applied to them is even more flawed”. But he is certainly right in saying that these factors can be controlled enough to disprove your 50 year outlook.
    If Hansen and NASA had stood up to the environmemntal lobby a few years ago and pushed for control of these gases as they proposed, then the pop press might now be yelling, “Hey folks, these are true pollutants, we can do something about them now and we should see results quickly” Add to this other forcings such as land use, and new focuses such as actual earth regions rather than abstract globes, etc. and we find a lot can be done. Who knows, if we were pragmatic realists, we might even eliminate the climate problem in 50 years.
    But it won’t happen, folks would rather have their point of view prevail then see results. All hail the great CO2 monster!

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  89. Mark Bahner Says:

    Roger,

    You write, “Thanks, but you are asking me if I can read a graph. The answer is yes.”

    No, I was not asking you if you could read a graph. I was asking you what scenario on that graph most closely follows climate forcing to date.

    You continue, “Yes, to date the emissions path has followed what Jh now calls his AS.”

    Finally! Why didn’t you simply answer that in the first place?!!

    BTW, you STILL are slightly (but importantly) wrong; the graph has climate forcing, not emissions. That’s important, because there is very important scientific uncertainty about methane emissions versus the change in methane climate forcing. The change in methane *climate forcing* (i.e., the increase in methane atmospheric concentration) has essentially gone to zero:

    http://www.cmdl.noaa.gov/gallery/ccgg_figures/ch4_tr_global

    …but the trend in methane emissions is far less certain.

    So…if you agree with me that the past trends in climate forcing have most closely resembled Hansen’s Alternative Scenario (AS), don’t you agree that you were wrong when you said (to Gavin Schmidt),

    “…I am aware of no policy proposal being discussed that comes close to your AS”?

    How can you not be aware of any policy proposal being discussed that comes close to the AS (Alternative Scenario), if you agree that the TRENDS TO DATE have been closest to the AS??!

    Mark

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  91. Mark Bahner Says:

    Hi Roger,

    I might not have made what I’m thinking very clear.

    I agree with your statement, “No emissions reduction policy currently under discussion – from changes in personal behavior to those proposed under the Framework Convention on Climate Change – even if successfully implemented will have a perceptible effect on the global climate system for at least 50 years.”

    I also agree that Gavin Schmidt set up a straw man for contrast. But where I think you’re 180 degrees wrong is the direction of that straw man. You said that the straw man was on the low side…the Alternative Scenario. But as you yourself can see, the climate forcing to date has been closest to the Alternative Scenario (of all 5 scenarios in James Hansen’s AGU presentation).

    The strawmen that Gavin Schmidt gave so that he could claim there was a significant difference were the “business as usual” scenarios he chose. He gave the scenarios of the A2 and A1B. But if you go to Figure 1 of the paper he referenced:

    http://pubs.giss.nasa.gov/abstracts/submitted/Hansen_etal_1.html

    http://pubs.giss.nasa.gov/docs/notyet/2005_submitted_Hansen_etal_1.pdf

    …you’ll see the that A2 and A1B both have a CO2 concentration in 2050 of a whopping 533 ppm. And the methane concentrations are even more ridiculous: approximately 2400 ppb for A1B and 2600 ppb for A2.

    In order for the CO2 concentration to be 533 ppm in 2050, the AVERAGE annual increase between now (~382 ppm) and 2050 would have to be approximately 3.43 ppm. That’s almost DOUBLE the average increase over the past 25 years. That is simply not credible.

    The methane concentration likewise require AVERAGE increases of >10 ppb per year. The average increase over the past 5 years has been…essentially ZERO ppb.

    So the A2 and A1B scenarios are obviously nonsense. It’s not surprising that the Alternative Scenario will be different from two scenarios that have essentially ZERO chance of happening.

    In contrast, from that same figure, the Alternative Scenario values for CO2 and CH4 in 2050 are approximately 440 ppm and 1550 ppb, respectively.

    These values can be compared to my “50% probability” values for 2050 of 477 ppm and 1810 ppb, respectively, for “do nothing.” The difference in temperature between the two would not be perceptible (probably a little more than 0.1 degree Celsius).

    So you’re right about the straw man. But the straw man scenarios are A2 and A1B…not the Alternative Scenario.

    And you’re also right that the difference would not be perceptible. There will probably be about 0.6 degrees Celsius increase for “do nothing,” and a little less than 0.5 degrees Celsius for the Alternative Scenario.

    Mark

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  93. Mark Bahner Says:

    Hmmmm…

    Even more thinking about this, and re-reviewing the latest surface and satellite temperature trends…

    It seems more likely that the 50% probability for “do nothing” in the next 50 years would put the warming at more like 0.8 degrees Celsius (not 0.6 degrees Celsius, as I’ve previously stated).

    Therefore, comparing the 50% probability for “do nothing” to the Alternative Scenario (AS) for the next 50 years would be more like 0.8 degree Celsius versus 0.5 degree Celsius temperature rise from present, respectively.

    I’d consider that (a 0.3 degree Celsius difference) “perceptible”…though just barely.

    So here are alternatives to your sentence that I’d suggest:

    1) “No emissions reduction policy currently under discussion – from changes in personal behavior to those proposed under the Framework Convention on Climate Change – even if successfully implemented will have more than a barely perceptible effect on the global climate system for at least 50 years.”

    2) “No emissions reduction policy currently under discussion – from changes in personal behavior to those proposed under the Framework Convention on Climate Change – even if successfully implemented will have a perceptible effect on the global climate system for at least 30 years.”

    Note that the second sentence shortens the time frame from 50 years to 30 years. This is important, because I estimate that even the “do nothing” approach would result in only about 0.5 degree Celsius temperature rise in the next 30 years…and no policy currently under discussion could cut that rise enough to be “perceptible.”