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Pielke Sr. Agrees with SkS on Reducing Carbon Emissions

Posted on 25 September 2011 by dana1981

Dr. Roger Pielke Sr. has responded to our last set of questions and answers, and we would like to thank him for a civil discourse to this point.  To sum up the discussion, there are some points on which we agree, others on which we did not find agreement, and a few others which require further clarification. (Dr. Pielke's final summary is here).  In this post, we will summarize the agreements in the text below, based on our understanding of Dr. Pielke's comments.  Readers are invited to read Dr. Pielke's comments to verify that we are accurately representing them in this summary.

Reducing CO2 Emissions - the Prudent Path

We believe Dr. Pielke framed the prudent path forward with regards to addressing the risks posed by climate change very well (emphasis added):

"The emission of CO2 into the atmosphere, and its continued accumulation in the atmosphere is changing the climate. We do not need to agree on the magnitude of its global average radiative forcing to see a need to limit this accumulation. The biogeochemical effect of added CO2 by itself is a concern as we do not know its consequences. At the very least, ecosystem function will change resulting in biodiversity changes as different species react differently to higher CO2. The prudent path, therefore, is to limit how much we change our atmosphere."

Dr. Pielke further clarified his position in a later comment:

"I am very much in favor of energy sources which minimize the input [of] gases and aerosols into the atmosphere. Much of my career has been involved with reducing air pollution (both in research and in policy). What we should move towards is an economy with as small a footprint on the natural environment as possible."

We strongly agree with Dr. Pielke on this issue, as we have previously written, and we hope climate "skeptics" heed his sage words. 

Other Climate Influences Must Also be Addressed

Although CO2 is one of the primary causes of the current climate change (more on the magnitude of its effects in a separate post), we agree with Dr. Pielke that other climate influences such as land-use change must also be addressed through climate policy.

Common Ground

We are pleased that we were able to find common ground with Dr. Pielke on the need to take serious action to reduce human CO2 emissions.  We agree that other anthropogenic emissions (including aerosols) and land-use change are issues which must also be addressed (for example, see the United Nations Collaborative initiative on Reducing Emissions from Deforestation and forest Degradation [REDD]).

Although we did not find agreement with Dr. Pielke on all issues, we feel that the need to address these problems is the most important issue in our discussions, and we hope he will communicate the 'prudent path' to policymakers when given the opportunity.

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Comments

Comments 1 to 44:

  1. He closes with "In terms of how to do this with respect to carbon emissions, I completely agree with my son’s perspective as he presents in The Climate Fix" Has anyone read this? I just ordered a copy ($10.40 from the Amazon bargain bin).
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    Moderator Response: Clarification: The statement quoted was made by Dr. Roger Pilke Sr. The book was written by his son, Dr. Roger Pilke Jr.
  2. No, we didn't comment on the specific plan because I don't think anyone at SkS has read it, Eric. We'd be interested in hearing your comments one you have a look.
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  3. The points of agreement are interesting; the points of disagreement should be equally so.

    What I gathered from this discussion was that Dr Pielke does not disagree that CO2 is a substantial forcing, but simply believes that it does not contribute to climate change such a large proportion of the forcings that it should be acted upon in isolation. Dr Hansen has published papers when he attempts to estimate how much CO2, aerosols, land use, and other factors contribute. I'm not sure if Dr Pielke has made similar estimates, but I'd be interested in them if they exist.

    What I'm coming around to is that there are always tradeoffs to be made in any course of action to be followed, and the way to decide the course to follow is to focus most of your efforts on the actions with the best cost/benefit ratios. To the best of my knowledge, reducing CO2 emissions still gives of the most bang for the buck. (Is that a local colloquialism or is it more widely understood?) If you can't get the leaders of the major industrial powers to agree to some plan for reducing emissions, I don't know how you would go about trying to convince millions of individuals in growing populations to quit converting forest to farmland, just for example.

    I probably won't read

    The Climate Fix: What Scientists and Politicians Won't Tell You About Global Warming

    because the subtitle hints strongly at conspiracy and subterfuge, and that turns me off. So, I should not comment, but I will anyway, but this is just based on a skim of comments and reviews.

    The "iron law" to the effect that if economics and environmental issues come head to head, economics wins, has some merit, but this is a matter of public perception. When a river catches fire because of the all the pollutants in it, the public perceives that maybe they are better off with some pollution regulation rather than purely capitalistic industrialism. It would be naive to think that fossil fuel corporations are not aware of this, which is why, in the US, we see advertisements about how coal is clean, natural gas fracking is safe, and tar sand oil is secure.

    It would also be naive to think that major industrial powers don't have influence on governing bodies, and naive as well to think that corporations producing fossil fuels will not recognize the advancement of alternative energy sources as a threat. So, I have little faith that laws and regulations which change the balance of favored energy sources will change until there is public outcry, at least not in the democratic countries.

    Based on the material I've read, I believe these critiques apply to the main gist of the book, but I'll stand corrected if someone points out otherwise.

    P.S. Yes, I am aware of the irony/hypocrisy that I won't read the book because of the implied subterfuge, and that is exactly what I'm saying is happening. I'm not proud; I can handle it.
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  4. One proofread too little:

    Dr. Hansen... _where_ he attempts...

    ...favored energy sources will _be enacted_ until...
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  5. @ Chris G., #3:

    I would guess that the (somewhat cynical) "iron law" holds in normal times. However, in times of crisis, I believe the iron bends. For instance, what was the economic advantage to passing the laws that were responsive to the Civil Rights movement?

    It's very possible that there will not be any effective laws passed until the economic harm is more visible.

    I refer to:
    http://www.doonesbury.com/strip/archive/2011/09/25
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  6. As a laymen I have been following the exchange between Dr. Pielke and this site very closely.

    Dr. Pielke is someone that understands the physics, (-Ideology snipped-) and agrees with points of view espoused here, and yet comes to different conclusions.

    I did not see any credible refutation of his work here, simple disagreement with his conclusions. (-Inflammatory snipped-).

    He made the claim that man-made CO2 was responsible for about 26% of the yearly global emissions. I did not see any refutation of this claim. He also stated there were many other factors affecting climate irrespective of CO2 alone; Again, I did not see any credible refutation of this position.

    "Global warming or cooling involves changes in Joules of heat in the climate system. This involves changes in heat in the oceans, land, atmosphere and cryosphere. As concluded by Jim Hansen and others, the ocean is by far the component of the climate system where the large majority of this heating and cooling occurs. Receding ice, surface temperature, atmospheric temperatures make up only a relatively small portion of global warming and cooling."

    If you feel ignoring other aspects of the climate while elevating CO2 to a greater position of authority, there is not much one can do, but this does not ultimately make the scientific case.

    You may have proven that CO2 is a GHG, but you have not proven that it is the primary driver of climate overcoming all other factors.

    As Einstein states:

    "No amount of experimentation can ever prove me right; a single experiment can prove me wrong." -
    -- Albert Einstein
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    Response:

    [DB] Ideological insinuations of fraud snipped.  And do please try harder to be less inflammatory.

    AFA Einstein: he said many a thing.  My favorite by far:

    Any man who can drive safely while kissing a woman is simply not giving the kiss the attention it deserves.

  7. Dana69, did you read this very recent article on ocean heat on SkS, or a number of older articles? SkS regularly deals with ocean heat content. Oceans are warming, as measured directly through OHC and indirectly through sea level rise. Cherry-picked short-term trends don't change that.

    Human emissions are not responsible for 26%, of yearly global emissions. Neither SkS nor Dr Pielke made your erroneous claim. Pielke claimed 26% of the positive radiative forcing was due to CO2 emissions. His claim does not seem too strong either, given the trend of natural forcing factors since the 1960s, and certainly natural factors cannot account for the trend in temperatures. Pielke also avoided answering what proportion of global warming (temperature) was due to CO2 emissions.

    "... many other factors affecting climate irrespective of CO2 alone". See if you can find anyone that disagrees with that statement! The only problem is that CO2/GHG forcing is the strongest of all the forcings currently in action. SkS did not need to "refute" it.
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  8. Dana69... "...and yet comes to different conclusions."

    I wouldn't be so sure about that. Can you give an example? It seems to me that Pielke was, to a certain extent, taking a different path to the same conclusions, that as a species we need to address our use of fossil fuels and quickly switch to clean sources of energy.
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  9. Rob Honeycutt,

    It appears you didn't read his response here SkS Responses to Pielke Sr. Questions @17 which states:
    "A focus on the radiative forcing of added CO2 as the dominate environmental threat is not supported by the scientific evidence. Policies that focus on that single issue which result in negative effects on other environmental and social concerns is not good policy, in my view."

    Or maybe you skipped this response @94: No; "I am not convinced that CO2 is the largest annual global averaged positive radiative forcing [and I am interpreting that you mean human climate forcings and the global annual average). Sott, and a variety of other aerosols have quite substantial positive radiative forcings in the atmosphere, and for soot,at the surface on snow and ice also. These other positive radiative forcings arr discussed in some depth in."

    This site continues to claim that Radiative Forcings caused by CO2 is the first order climate driver causing the current global warming trend, and this is considered settled science.

    Clearly another valid scientist disagrees.

    He also takes issue with climate models, which this site clearly relies heavily on when he states at @94:

    "I also have concluded that the computationally expensive climate models, when used for multi-decadal predictions, have not told us anything of demonstrated added value beyond what can be achieved with just global energy balance models. By so closely linking policy to these models, we are doing more harm than good in developing effective climate and energy policies."
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    Response:

    [DB] "This site continues to claim that Radiative Forcings caused by CO2 is the first order climate driver causing the current global warming trend"

    You'll have to provide a link to support this assertion, for at this juncture it's simply unsupported.

    "and this is considered settled science."

    IBID

    "Clearly another valid scientist disagrees."

    And whom would that be?  Or do you refer obliquely to RPSr?

    "computationally expensive climate models"

    Since when does it really matter what the computational cost of a model is and what are RPSr's credentials in being an expert in that area?

    "when used for multi-decadal predictions"

    So using models for an area (multi-decadal vs centennial or millennial-scale) outside of their design core functionality makes them more expensive to run?

    "have not told us anything of demonstrated added value beyond what can be achieved with just global energy balance models"

    Insights, sir, insights galore.

    "By so closely linking policy to these models, we are doing more harm than good in developing effective climate and energy policies."

    At last, the underlying pea is revealed.  You object to policy changes from the status quo and set up straw men and houses of cards in a failed attempt to cloak policy objections with unsupportable science.

    Please note that SkS is about discussing the science of climate change and exposing the mythologies behind those that would seek to obfuscate it.

  10. I think my friend the climate pirate says it best: We can’t deal with a problem without knowing its scope. That Pielke Sr. agrees CO2 causes some global warming is not something to shout hooray for.

    We need to know if the appropriate approach is to politely petition people to change their lightbulbs, or to ban air travel and coal power. The world is full of climate "realists" who want to call themselves environmentalists because they put their orange peel in the trash rather than throwing it on the ground (I'm serious. This was used as an example by a guy in earnest).

    I actually think this should be a Climate Myth with rebuttal on this site; "Why can't we all just get along? Don't we all want fresh air after all? Do we really have to bother with this controversial climate change stuff?"
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  11. Dana69 #9, just because you've found a single scientist who disagrees with the consensus that anthropogenic GHGs are the dominant current driver of climate change does not change the fact that virtually all relevant climate scientists concur with this observation (97-98%; e.g. Anderegg et al). They are supported by a wealth of physical observation, including but not limited to: the observation of the enhanced greenhouse effect (downward and outgoing longwave radiation), of a warming pattern consistent with GHGs rather than other drivers, and of palaeoclimate and geological observations consistent with a climate sensitivity of 3C/doubling CO2. You can claim the 'site relies heavily on models', unfortunately, the evidence is in a great deal of observation from a great variety of sources, not just the models (which are based on physics so not to be dismissed).

    Dr Pielke has not explained how to drive palaeoclimate with a low climate sensitivity to forcing. Can you?
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  12. Dana69 #9:
    He also takes issue with climate models, which this site clearly relies heavily on.
    Nope. This is a Monckton/Delingpole myth. Read the skeptics guide - there are multiple sources of observational evidence for almost every single claim of climate science.

    Warming world? There are weather stations, ships, bouys, satellites, glaciers, lakes, ice caps, boreholes, plant and animal species migrations, corals, pollens, tree rings.

    Warming due to greenhouse effect? How about the diurnal temperature range, winter vs summer warming, stratospheric cooling, tropopause rise, increased DLR, decreased OLR. (D = downward, O=outgoing, LR=longwave radiation)

    CO2 role in greenhouse effect? How about Tyndal's experiments in 1859, repeated and updated hundreds of times, gas spectroscopy, predictions from QM (probably the most successful theory in the history of physical science), the DLR spectra, OLR spectra, and also energy balance calculations.

    Future impacts? How about the paleoclimate data from previous interglacials, from the deep past, simple projection based on equilibrium sensitivity, energy balance calculations based on 20thC climate.

    And that's all from one lay person's reading. In fact, I can't think of a single claim of climate science, apart from perhaps regional predictions of the impacts of climate change, which isn't supported from multiple observational sources. Can you?
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  13. Dana69 reminds us of this claim by Dr. Pielke:
    "computationally expensive climate models, when used for multi-decadal predictions, have not told us anything of demonstrated added value beyond what can be achieved with just global energy balance models."

    As often happens, there's something untold behind this claim, i.e. that he's looking only at temperatures. This is resonable because this is the only thing that a simple energy balance model (EBM) can give. What surprises me, instead, is that it's him to consider temperature as the only important quantity. I'm sure Dr. Pielke knows very well that there's much more than global average surface temperature in the climate system.

    Apart from this, is it really surprising that a simple EBM is good enough to project the temperature over a multidecadal time scale? I don't think so, the physical foundations of the AGW theory are indeed as simple as a zero-dimensional EBM and it's exactly this that makes the AGW theory so strong. If anything, Dr. Pielke's claim supports the AGW theory.

    I'd suggest the reading of this interesting blog post by Dr. Isaac Held.
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  14. Dana69 How are global energy balance models used to make regional projections? GCMs can do this, can EBM.

    One might equally ask Prof. Pielke why we should use energy balance models when they don't tell us anything we couldn't be achieved using simple statistical regression models.

    The obvious answer to that question is that EBMs are based on more physics than statistical model; the answer to Pielke's question is pretty much the same, the GCMs include more physics than EBMs.

    The really funny thing is that the most common complaint about GCMs is that the climate is too complex for them to model, but here Prof. Pielke says we should use even simpler models. So why doesn't the complexit argument apply to Prof. Pielkes energy balance models? ;o)
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  15. However I think the comparison between EBMs and GCMs gives us a very interesting piece of information: An EBM with the same response function as a GCM gives the same evolution of temperatures over time as an ensemble of runs of that GCM. (See for example Hansen's 2011 draft paper on energy balance, or Held's blog post linked by Riccardo).

    However the individual GCM runs give significant variation about this mean.

    That should tell us something about the physics. My interpretation is as follows: Despite the fact that the temperature can vary significantly in the short term due to internal variability (ENSO, cloud feedbacks etc), the system is fundamentally stable with respect to the equilibrium temperature for a given level of sustained forcing. Or equivalently, the system has a rather limited memory for what has happened in the past. Does that seem right?
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  16. Dana69 becoming very much an underdog- I'd like to respond with a slightly different approach-

    Dana69, you asked for a "refutation" of Dr. Pielke Sr. Could you please summarize how Dr. Pielke arrived at his contention that CO2 isn't the dominant climate driver? What is the observational and experimental data behind it? What is the total forcing that Dr. Pielke believes exists? How does that compare with the consensus forcing and CO2 participation? I wasn't able to find this in the discussion he presented, and I don't think it's reasonable to expect a refutation of something that's not there. I probably missed a thing or two that you can fill in, but overall, I don't think its there. What I observed was a fair degree of frustration from the SkS side trying to get at this so it could be discussed and Dr. Pielke rebuffing repeated requests to do so.
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  17. My understanding is that CO2 is all about heat and nothing but heat. It is my belief that Climate change as driven by accumulation of CO2 in the atmosphere will be irrefutably proven when we can do away with either of the instruments used to detect heat and CO2 levels.
    We should be able to tell the temperature by using CO2 levels as an indicator and we should be able to tell the CO2 levels by reading a thermometer. A bit simplistic but that is the purpose. To cut away all of the extraneous contention.

    That is why Pielke.sr says that the EBMs can tell us all we need to know and as most of the heat resides in the Oceans that is where we should be focusing and using OHC as our chosen metric.
    We have weather prediction models to do the rest (modeling the atmosphere skillfully).
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  18. FundME: Yes, if we reach the point where CO2 and temperature have been tracking consistently over many decades, then that would be strong evidence (although correlation does not prove causation, and to even provide strongly suggestive evidence we'd need some serious bumps in the shape of the CO2 growth, which has been disappointingly smooth up till now).

    The problem is that this method is likely to not give a clear answer until long past the point where we have committed the planet to huge irreversible changes.

    And it is also demands that climate science work in a fundamentally different way to any other science. In no other field do we force scientists to abandon all the accumulated knowledge of physics from other fields, and rebuild from scratch on a purely statistical basis.
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  19. Why is this thread going off topic about models and such? I know, go back to the post made at #9. We have discussed that ad nauseum on another thread with Pielke. Please take arguments about models to the relevant threads. Thanks.

    This post is about what Pielke (a "skeptic")and SkS agree on. Specifically, that a) we humans are altering our climate by emitting GHGs and b) we agree that we need to reduce our GHG emissions-- it is all there in black and white.

    That we agree on something is a good thing. Unfortunately, some contrarians are not happy with that and now seem bent on fabricating debate on well, just about anything for the sake of being argumentative and to shift focus away from the fact that we are in agreement on two critical issues as noted above.
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  20. @Albatross #19

    I heartedly concur with your assessment.

    BTW, climate models will once again be dealt with in Dana's next post about where SkS disagrees with Dr. Roger Pielke, Sr.

    Speaking of Dr. Pielke, it will be intersting to see whether or not he takes issue with anything stated in the above article.
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  21. KevinC
    I agree it would be a terrible waste of hard work and creative thinking to bin the GCMs but perhaps the output should be a little muted until they become more skillful. I mean this purely from a public perspective, we all decry the over hyping of results from published papers by the MSM and any tiny flaw is always thrown into sharp relief so eroding the general public's regard for Science.
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  22. FundME, #21:

    That isn't the way that science is done. You have to put out the best that you have - warts and all.
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  23. Dana69 @6:
    "He made the claim that man-made CO2 was responsible for about 26% of the yearly global emissions. I did not see any refutation of this claim.
    You didn't see a refutation of this claim for two reasons. One, that's not what he said. What Dr. Pielke said was that CO2 is responsible for 26% of the net positive radiative forcing, which is very different than what you claim he said.

    Second, we haven't published our post on disagreements yet. This is one area where we disagree (Dr. Pielke is off by a factor of ~2), as we will discuss in the post scheduled to be published tomorrow.
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  24. #5 NealJKing,
    No disagreement; the iron will bend. However, I worry that the damages have to be pretty obvious before they are acknowledged. We've seen drought and fire in Australia, Russia, Mexico (drought only?), the southern US, the Amazon, China, and possibly others that I can't recall off the top of my head. All of these have occurred in a fairly short sequence of years, and I believe all are consistent with shifts in circulation patterns expected out of a warming world, and still there is reluctance to accepting that there might be a relationship.

    The agreement from Dr. Pielke that CO2 is a significant forcing is interesting, but I'm not sure that everyone understands the limitation on how he frames the statement, "We do not need to agree on the magnitude of its global average radiative forcing to see a need to limit this accumulation."
    He is probably making the statement in the context of a sensitivity to 2x CO2, and as far as that goes, he is correct, and estimates do vary. However, the sensitivity and the direct forcing are separate entities. And, as I recall, the band of values for direct forcing is pretty narrowly defined based on the physics of gas spectroscopy. The limitation in the statement, and the implications about how to direct mitigation efforts, is that there is no set magnitude for either. As CO2 levels increase, the magnitude of the effect increases; there is no upper bound.

    Looking forward to the post on the disagreements.
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  25. Can I suggest that SkS seeks out other published scientists whose work the sceptic community holds dear to their hearts as supporting a contrarian viewpoint, and looks for areas of agreement -- just as has been done here with Dr Pielke? Being able to demonstrate, unequivocally, using the published words of those scientists, that they do support action to reduce GHGs, is a very powerful tool.

    Though I'm sure it will be difficult for some to admit, to some degree, agreeing the minutiae of the science is less important than action to stop the negative climate effects that we -- those on this side of the divide -- all fear.

    Let's face it; none of us are doing this because we like a good argument.
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  26. Dave123 @16

    You ask me to validate Dr. Pielke Sr. data. He provides his supporting data in most of his posts.

    "First, the climate system is much more than just a globally averaged surface temperature. Even with respect to global annual averaged radiative imbalance, the retention of the scientifically inaccurate use of surface temperature trends (with its lags) is unnecessary. The changes in the ocean heat content over time, when accurately measured, provides a diagnostic of the radiative imbalance without the need for considering lags or a so-called “climate sensitivity”."

    ( -Snip- )

    I am going to go outside the bounds for a second and tell you I have been following Dikran Marsupials responses, both here and other sites, and I have to say he has an impressive intellectual mind. I am not sure of his background, or credentials, but he is someone with a firm grasp of ideas and an impressive array of responses.

    Are peoples credentials published here, or is this more of a closed site for peoples backgrounds?

    Lastly, I was wrong when I stated:

    "He made the claim that man-made CO2 was responsible for about 26% of the yearly global emissions. I did not see any refutation of this claim.

    I was corrected when it was pointed out Dr. Pielke actual stated: "that CO2 is responsible for 26% of the net positive radiative forcing, which is very different than what you claim he said."

    I am not sure what the specific difference is, but it does seem to suggest that it is not the entire equation. It may be a factor, but not THE factor. The only implication of this conclusion is political, not scientific. Science talks about what is, politics talks about what ought.

    Respectfully,
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    Response:

    [DB] Quote seemingly attributed to RPSr snipped due to language.

    "Are peoples credentials published here, or is this more of a closed site for peoples backgrounds?"

    What matters at SkS is the scientific strength of the argument, not any credentials.  Participants comments are thus judged and weighed on their own merits.  Nothing else need matter.  That being said, some members of SkS have a short bio located here (not a comprehensive list).

    "It may be a factor, but not THE factor."

    Based on what?  You give us nothing to work with here.

    "The only implication of this conclusion is political, not scientific."

    Actually the scientific implications dwarf the political ones.  If the laws of physics are any guide, a great deal of humanity stands to find out those selfsame implications.

    "A man should look for what is, and not for what he thinks should be." ~ Albert Einstein

  27. Dana69 @28 - that CO2 is not the only factor was another of our agreements with Dr. Pielke, discussed in this post.
    "Although CO2 is one of the primary causes of the current climate change (more on the magnitude of its effects in a separate post), we agree with Dr. Pielke that other climate influences such as land-use change must also be addressed through climate policy."
    CO2 is, however, the largest single factor causing global warming (again, we'll discuss this further in the Disagreements post).

    As a side note, the Disagreements post will likely be delayed to give Dr. Pielke a chance to respond to this post, as he's currently traveling.
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  28. also Dana69 @28:
    "I am not sure what the specific difference is"
    Man-made CO2 is actually only about 3-5% of annual global CO2 emissions. However, the natural carbon cycle is in balance (nature absorbs slightly more carbon than it emits), so humans are responsible for 100% of the annual atmospheric CO2 increase.

    However, what Dr. Pielke was referring to was the global energy imbalance. Effects like an increased greenhouse effect or increased solar activity can throw off the Earth's energy balance, leading to more incoming than outgoing energy. Global warming is the result of this sort of energy imbalance. Dr. Pielke claimed that CO2 was responsible for 26% of the current energy imbalance (the rest is other greenhouse gases, black carbon, etc.). Based on the scientific literature, we believe it's twice that (about 50%).
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  29. dana1981 @28

    I would also very much like to see Professor Pielke explain the 26%. I have been through the calculation on his web site which appears to differ considerably from that made in the TAR. As he said this was a back of the envelope estimate from several years ago which probably explains why I found it so odd to follow. I am sure he would appreciate the opportunity to clarify with the latest data. An update of his website would be useful.

    It appears to me that an estimate of CO2's relative impact now and in the future is central to differences expressed in the previous posts over his hypothesis 2a and 2b. I read his EOS forum article and references but could not agree with him that the literature provides support hypothesis 2a over 2b. I am inclined to think that my approach seeking quantitative estimates of forcing is not his approach. Unfortunately I have not been able to find his analysis in the literature.

    In some ways I find hypothesis 2a has some merit. I think if I have understood Professor Pielke's viewpoint correctly he has concerns that by focusing constantly on global change we miss the point that we will all experience climate change locally. Some anthropogenic changes such as BC in the Himalaya or land uses change such as deforestation in the tropics will have far a greater local than global impact on climate. Although perceived as small effects on the global stage compared to CO2 they could remain significant concerns to those affected. Perhaps we could find more common ground by understanding why he thinks CO2 is not the dominating issue for the coming century.
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  30. mdenison - I think Pielke believes the methane and black soot forcings are underestimated. I certainly disagree on methane, as will be discussed in the Disagreements post. Black carbon he may have something of a point. It's possible that both the negative and positive forcings from aerosols and black carbon are underestimated by the IPCC. I think we discuss this in the Disagreements post too.
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  31. "The changes in the ocean heat content over time, when accurately measured, provides a diagnostic of the radiative imbalance without the need for considering lags or a so-called “climate sensitivity"

    Of course, RPSr said this a couple of years ago knowing fully that data on OHC - the entire ocean - is sparse and not nearly (to put it mildly) as well-measured as surface temps.

    And of course there's nothing like the historical record we have for surface temps.

    He then pinned his notion that there's nothing really serious to worry about on the lack of data on OHC.

    Utterly transparent from the git-go.
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  32. Dana - Good work on this. One comment:
    Dr. Pielke claimed that CO2 was responsible for 26% of the current energy imbalance (the rest is other greenhouse gases, black carbon, etc.). Based on the scientific literature, we believe it's twice that (about 50%).
    I thought I may as well check this against the GISS forcings (which I note they've now updated to 2010, hoorah!) here.

    But how do you count? Net forcing relative to 1880 is about 1.5W/m2. The CO2 contribution to that is 1.5W/m2, or 100%. But that's meaningless.

    If we add up just the GHGs, then CO2 is 1.5 out of 3.0W/m2, which I presume is your 50% figure.

    If we naively add up all the positives in the top graph and ignore the negatives, then CO2 is 1.5 out of 4.1W/m2, which is still 36%. That's the most generous figure I can get, so I guess RPSr disagrees with the GISS forcings.
    0 0
  33. Kevin C - Skeie et al. (2011), published last month provides another set of forcing estimates up to 2010. Time series graphs on page 31 of the pdf.
    0 0
  34. Thanks Paul. Skeie et al use GISS for their GHG data, so that much is identical. However it looks like their aerosol data is rather different. I'll try and get hold of the data.

    They give a figure for total anthropogenic RF of 1.4W/m2, of which CO2 contributes 1.8W/m2. That's even further from RPSr's figures.

    By eye, I'm guessing that their forcings will better reproduce the temperature peak of the 30s/40s, but fail to reproduce the 'hiatus' of the last decade. So their aerosol forcings are significantly different from those of Kaufman et al. But they only give decadal values. However, there is something odd going on: It seems to me that the decadal SO4 numbers in Table 3 don't match the plots in figure 2b. I'll post a comment on the article.
    0 0
  35. Kevin - One key point of difference is that the GISS net forcing graph b includes solar, whereas Skeie et al. only consider anthropogenic variables.
    0 0
  36. Hmm I wonder why GISS puts CO2 at 1.5 W/m2. The IPCC put it at 1.66 W/m2 in 2007, and I calculate it at 1.77 W/m2 now.
    0 0
  37. dana1981 - According to the title of GISS figure 28a 1.5 W/m2 is the forcing difference only up to 2000. Your calculation is close to Skeie et al.'s 2010 CO2 forcing as quoted by Kevin above.
    0 0
  38. Could this be where RPSr is getting his 26% figure? If you include water vapour as a forcing rather than a feedback, then the contribution of CO2 is much smaller by proportion. However you would then have to argue that the increase in water vapour in the atmosphere was independent of the increase in temperature due to GHG forcing. If you believe sensitivity is low, then the temperature change due to anthropogenic GHGs is low, then the increase in water vapour must come from somewhere else, and so can be considered a forcing.

    See for example this table in the Wikipedia article on Greenhouse gas.
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    Response:

    [DB] Added link.

  39. Dana69-

    There is clearly a disconnect, as I didn't ask you to validate Dr. Pielke's data. I asked you to show where he offered any. Your responsive quote is an opinion expressed by Dr. Pielke, a conclusion, not what the underlying data is. If you see the confusion in the posts between then and now I think you might find that a good faith effort is being made to figure this out. Please also note in the comments a willingness to explore changes (albedo vs methane) rather than a knee-jerk adherence to the IPPC. This is a good crew.

    Dana1981 is going to provide reason why the SkS side believes that Dr. Pielke is off by a factor of 2 on the role of CO2 in the global energy imbalance. But without Dr. Pielke's data and reasoning for his 26% we lack a complete story.

    The problem is that instead of putting this data into the posts, Dr. Pielke provided it in references. The 26% is an admitted back-of-the-envelope calculation provided in this Slide presentation:

    Source Presentation

    .

    However, this isn’t a peer reviewed publication.
    In slide 11 and 12 however, he cites research showing
    1) An increase of 0.5 in total radiative forcing
    2) Increased contributions from a number of other components

    Now, I can’t duplicate 26% for CO2, I get 31% and CO2 remains the largest single factor regardless. The IPPC reference on slide 9 is not a currently functioning link, and I can’t get the IPPC number to come out to 58% either. But this is to be expected eyeballing graphs.
    I want to add a cautionary note regarding Dr. Pielke’s higher value for methane. One of the catastrophe theories related to AGW is the release of methane from permafrost and subsea methane clathrates.

    There is concern about the margins of the Siberian Artic Shelf

    Real Climate Discussion


    The RealClimate folks take a non-alarmist position on this. But there is a short notice expedition to the area because of concern about accelerated rates.

    Expedition


    Given that the rate of decline of ice in the artic has been underestimated by the IPPC, and our lack of knowledge in general of this formerly ice-bound area I think book makers might start shading the odds of a significant methane release. In other words, while Dana1981 has said he will argue for Dr. Pielke overestimating methane’s role, I’m worried that Dr. Pielke is right.
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  40. Oh yes, well done Dave for actually checking the sources! That is a much more reasoned position. And apologies to RPSr for suggesting that he might hold such a nonsensical view as the one I suggested at #38.

    The questions which immediately occur to me are:

    1. Have there been subsequent results on any of these observations?

    2. Do these represent a comprehensive survey of all the additional forcings which have been identified, or are there additional forcings (positive or negative) which need to be included as well?

    3. Are they all independent of the forcings included in the IPCC 2001 assessment?

    Assessing this has gone beyond my ability. The argument is also presented on RPSr's blog here.
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  41. And here is the response from Real Climate. (But I'm just parroting sources now.)

    (Link fixed. Sorry editors, I'm getting sloppy with my posts. Will try and improve.)
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  42. Anyone following the link to RealClimate on Dr. Pielke's 265 (in #41) should read through the comments. There is a fascinating back and forth between Gavin Schmidt and Dr. Pielke.

    What's also fascinating is that the tone between Dr's Pielke and Schmidt is to my ear entirely different than the tone that transpired here. It seems to me that Dr. Pielke treats (as he should) Dr. Schmidt as a peer and an equal. My ear heard Dr. Pielke treat the SkS group as anything but...and that to me is part of why the whole conversation blew up.
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  43. Professor Pielke explains his reasoning of the 26% here

    What Fraction of Global Warming is Due to the Radiative Forcing of Increased Atmospheric Concentrations of CO2?

    Dana #30 did suggest to me that we keep this subject for the 'Disagreements post'.
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  44. Having read the RC response and the exchange Dave pointed, and tried to work through some of the details myself, I'm tempted to conclude that the question is meaningless and attempting to answer it will generate more confusion than enlightenment. Although with enough research you might be able to whack the odd case of double counting.
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