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Comments 72751 to 72800:

72751. pielkesr at 09:39 AM on 11 October 2011
       Pielke Sr. and SkS Warming Estimates
       dana1981 - We know too little about the role of natural variations in the radiative forcing in the last century to know with such precision how much of that warming is from anthropogenic effects. This is based, in part, on the research and comments of Roy Spencer, Judy Curry, Judith Lean and others. [this is one reason I recommend you focus on science and not Roy's policy/political statements; he has added important new insight into the role of natural forcings including solar and internal multi-year variability]. Even with the anthropogenic forcings, we do not know what the actual aerosol and land use/land cover changes have contributed, relative to the radiative effect of added CO2, with respect to the observed surface temperature trends. There is also the issue of siting quality for the land portion of the surface temperature data. I agree that human's have significantly affected the annual average surface temperature trends, but, in my view, the issue as you present above inadequately considers all of the issues. Thus, I suggest we move on. I do not find this an important issue, but would be open to you explaining why it is. It seems to me that knowing the current forcings is much more relevant. P.S. I would like you to tell us if the water vapor/CO2 overlap was considered in your calculation. I do not see any problem in your calculation, if your numbers are used. We disagree with the values, however, as I wrote in my response.
72752. Lloyd Flack at 09:36 AM on 11 October 2011
       Book review: The Inquisition of Climate Science
       No money buys you an echo chamber where you hear what you want to hear. Yes, many in the fossil fuel industries are trying to cause consusion over climate change. But first they are confusing themselves. And it is not just profits. It is their sense of vocation, their belief that they are doing something beneficial to their societies that is threatened.
72753. dana1981 at 09:27 AM on 11 October 2011
       Pielke Sr. and SkS Disagreements and Open Questions
       A reminder from Hansen and Sato 2011:
72754. muoncounter at 09:19 AM on 11 October 2011
       Book review: The Inquisition of Climate Science
       DSL#53: "Gilligan's Island is a powerful commentary" Recall that GI included 'The Professor' among the castaways and the others did not blame him for their misfortune. A more modern version of this would have him 'voted off the island.' But the common theme to the bullet points in this post is not fear of technology, it is money talks.
72755. JMurphy at 09:18 AM on 11 October 2011
       Understanding climate denial
       elsa, what is a "warmist" and who do you believe are the "warmists" who have "commented here" ?
72756. elsa at 09:13 AM on 11 October 2011
       Understanding climate denial
       Michael Sweet: you say Dr. Lindzen says there is no link between smoking and cancer. I have not seen his views on this but I would have some sympathy. There is no causal explanation established (contrary actually to the CO2 warming theory where there is) between smoking and lung cancer although there is a high degree of correlation within one country between the two (it falls down when you try it across many countries I believe). You say past Presidents of South Africa denied that HIV caused AIDS. Actually I think it is one and I am not aware that he has any scientific credentials. No scientist has ever suggested this. You also say "Gravity theory has been challenged in the last few decades." I think the theory has been challenged by refinements to the basic theory, which is what happens if science is to advance. You say "All science advances by consensus." I could not disagree more and luckily I see I am not alone in this view in this blog, there are plenty of warmists who have commented here who understand that science advances from testing competing points of view, not consensus. If you need more help in this area I would be happy to explain it to you in more detail. Next you say "How much of this site is dedicated to modeling? Learn more about the data that supports climate science and you will lament models less." I find that the more I look at the models the less I am impressed by them.
72757. Alex C at 09:07 AM on 11 October 2011
       Greenland ice loss continues to accelerate
       @Lou: the graph's caption clearly states that it is based off of the average ice mass over the period 2002-2011. And yes I think you are correct regarding the expectation of cyclical patterns. It would also be incorrect to linearly connect the dots if they were not all based off of the same baseline.
72758. Eric (skeptic) at 08:46 AM on 11 October 2011
       Pielke Sr. and SkS Disagreements and Open Questions
       The glacial to interglacial temperature change is around 10C for a 50% increase in CO2, so the primary cause of the change s the ice albedo feedbacks as Tom pointed out above. So indeed it is true that "ice sheets formed due to the presence of ice sheets" and likewise melt due to the melting of ice sheets. Of course geography matters but mostly to the minimum and maximum states. One of the largest changes apart from ice albedo is weather. Here is one example: http://cci.siteturbine.com/uploaded_files/climatechange.umaine.edu/files/dentonTerminationsSci10-1.pdf: "Southward movement of the STF was a contributing factor for the large amplitude and rapid rise of temperatures during HS1 and the YDS within the region between 35°S and 45°S" which then caused glacier retreat. There is no way to tease out a 3C per doubling CO2 from a 10C per 50% rise in CO2 without a model and parameterized (i.e. not modeled) weather.
72759. Riccardo at 08:36 AM on 11 October 2011
       Book review: The Inquisition of Climate Science
       Reading your comments, both from the US and Australia, maybe my over-simplistic idea of the prevailing self-interest value is just part of the picture. Indeed, you showed that in many instances it did not prevail. This is not unique to the US, though, be sure that it applies to single european countries and to the whole European Union as well. Yet, at least when dealing with global problems the balance seems to be shifted more on the global interest side. Americans, and australians as Stevo suggests, seem to be more torn apart between the two opposites as if they can't find their preferred balance. We may add that the crisis started a couple of decades ago, when the USA political and economic leadrship started to decline and which, like any crisis, tend to make people or nations try protect themselves from the outside world. This translates, as muoncounter says, in not being able to take the necessary steps. I'm trying to understand how come that a great nation decide to turn its back to the world and steadly point backward. We know from history that great civilizations may and do collapse; if a society denies the very existence of a problem it won't be able to solve it for sure. I am optimistic, though. I belive that the american people are able to show a strong will once they face the unavoidable conclusion. In some sense, the climate Pearl Harbour didn't arrive yet and this is what we're here for, avoid another (worse) Pearl Harbour.
72760. DSL at 08:23 AM on 11 October 2011
       Book review: The Inquisition of Climate Science
       Agreed, dhogaza--on both comments--though I'd add that for me it was the idea of unions-as-progressive that was deflating. One more note for muon: let's not forget the contradiction in the social response to technology in the last sixty years. There was a great deal of fear of technology and science, expressed in thousands of SF movies and novels. I've always thought that Gilligan's Island is a powerful commentary on the response to the modern world. Anyway . . .
72761. Lou Grinzo at 08:21 AM on 11 October 2011
       Greenland ice loss continues to accelerate
       Every time SkS runs an update of this graph I have a hard time wrapping my brain around exactly what it says. So, I'm going to assume I'm not the only one staring at his or her monitor with a deeply furrowed brow, and ask if it means what I think it means... The data point for July 2011 looks to be almost exactly -1,100 GT. This means that it's 1,100 GT below the average of the July observations for 2002 through 2011, inclusive. Or does it mean that the July 2011 observation was -1,100 GT below the average of all 115 monthly observations (Jan 2002 through July 2011, inclusive)? Or is it something else entirely? Given the cyclic nature of the data, I think it's the second version, comparing each month to the average for the whole data set. In any case it means Greenland is losing a terrifying amount of ice.
72762. Bob Lacatena at 08:20 AM on 11 October 2011
       Understanding climate denial
       182, Jonathon,

       The odd thing about AGW, is that this is the first time I can remember people arguing about a scientific consensus, and whether or not one exists.

       Exactly my point. It rarely happens. It happened in a less precise way with tobacco and cancer. And CFCs and the ozone hole. But in those cases it was a lot more of "we don't know" than "there is no consensus." So why do you think there is this consensus argument now? If you go to look at all of the literature (search around scholar.google.com) and get a really good feel for what's going on in the field, versus what is pumped up in neon and sparklers in the blogosphere... what do you think? Forget studies, and surveys, and everything else. Just by glancing at scientific papers and seeing how most climate scientists talk to each other... is there a consensus? This isn't the thread to answer that question, but when you do get an answer, then you can ask yourself again about why this is the first time this question of "consensus" is arising, and the answer is a single word. I'll give you a hint. It begins with the letter "d."
72763. DSL at 08:14 AM on 11 October 2011
       Understanding climate denial
       Good point, muon. Consensus of opinion is important, though, because it can change the direction of scientific activity in a world of limited resources. The interface with the democracy is, after all, where the real battle is being fought right now, and that is the realm of the consensus of opinion, for better or worse. The same people who publicly tout Dr. Pielke as an example of non-consensus do so in order to sway public opinion against the position that something needs to be done--ironically, a position that Pielke has repeatedly endorsed. DM: Too many people use Kuhn to support the idea that progress is an illusion: paradigms will always be shifted--science changes like fashion. One interesting study into the idea of consensus is performed indirectly by Charles Mann in his 1491 (haven't seen 1493 yet).
72764. muoncounter at 08:13 AM on 11 October 2011
       Book review: The Inquisition of Climate Science
       Dave123#36: "in the US we believe deeply that one person's opinion is as good as another's. And it's all opinion you know. The resentment of there being people who actually know more or are smarter runs deep" That's a relatively recent development. Not all that long ago, the US believed in science and technology; we valued expertise, not opinion. We could build large-scale projects: we went to the moon based on the work of experts. Now we value opinion; anybody who 'can't see climate change in his own backyard' has an equal say in the 'debate.' Coincidentally, we have a country that can't get much of anything done. Is it any wonder we can't deal with complex issues? Is it any wonder we deny climate science and investigate scientists? We have an education system that ranks slightly behind Estonia. But who needs a good education when only opinion matters.
72765. muoncounter at 07:50 AM on 11 October 2011
       Understanding climate denial
       DikranM#181: This 'consensus is bad' argument is the ultimate strawman. Would those who challenge the value of consensus be satisfied if more climate scientists disagreed about the causes of climate change? The 'skeptic' who raises this herring is hoping that the subsequent discussion will forget that it is the consensus of the evidence, not the consensus of opinion that counts.
72766. Jonathon at 07:50 AM on 11 October 2011
       Understanding climate denial
       Scientific advancement can occur through individuals or groups of individuals (my post was not intented to mean one person working in a vacuum), and can occur through filling in small gaps of knowledge or through major breakthroughs. In eash case, the current mainstream view changes vased on the new work, as Dikran explained previously. Some changes can be imperceptively small, others can have dramatic effects. I have to agree with Sphaerica that nobody wakes up one day and says we have a consensus. Oftentimes, a consensus is never reached as differing theories keep moving in different directions (a classic example of this is the theoris of dinosaur extinction). The odd thing about AGW, is that this is the first time I can remember people arguing about a scientific consensus, and whether or not one exists.
72767. muoncounter at 07:41 AM on 11 October 2011
       CERN - Saying Nothing About Cosmic Ray Effects on Climate
       tblakeslee#140: "It appears that this blog is not about discussion to discover the truth but rather about promoting a dogma. ... you have shown that this is a religion and you are defending the faith. " What utter unsubstantiated nonsense. On this thread and on the parallel thread Cosmic rays: backing the wrong horse, knowledgeable people met your misconceptions with arguments backed by scientific literature; example here, to which you made no reply. And rather than admitting the factual errors in 'its the sun,' as shown here, you concoct a 'correlation is causation' argument that the well-known Arctic amplification is due to polar magnetic fields. There is nothing 'faith based' in this discussion, except your complete adherence to the doctrine of 'anything but CO2'. Now that's disappointing.
72768. dhogaza at 07:40 AM on 11 October 2011
       Book review: The Inquisition of Climate Science
       But we're getting way OT here and should probably wind this down ...
72769. dhogaza at 07:40 AM on 11 October 2011
       Book review: The Inquisition of Climate Science
       DSL: "All of this is shorthand, though. History is far more overwhelming than science." Oh, yes, after all it's the combined experience of billions of people over thousands of years ... I've just been tossing out some ideas for Riccardo to think about given some of his notions about the American people, and it's great to see others like you and dave123 add your thoughts. I wouldn't lay the weakening of unions entirely on globalization, not here in the US. Remember that anti-union Reagan had a lot of support among union rank and file workers. Reagan's conservative positions on social issues apparently resonated among such workers even though any rational evaluation would make it clear that voting for Reagan was voting against the economic self-interest of union workers. Globalization over the last couple of decades certainly had an overwhelmingly important role in weakening unions, though. Not only globalization, the rise of the "right to work" movement has allowed Boeing to retaliate against its unionized workforce in Washington by building a new 787 factory to be populated with lower-paid, non-union workers in the SE ...
72770. dhogaza at 07:31 AM on 11 October 2011
       Book review: The Inquisition of Climate Science
       critical mass, I'd say a critical reading of that thread, in particular gavin's inline responses to RPSr, mostly demonstrate that RPSr doesn't really know what he's talking about when he blows smoke about heat transport in the ocean. But that's for over there, not over here, where it's OT.
72771. dana1981 at 07:13 AM on 11 October 2011
       Pielke Sr. and SkS Warming Estimates
       Yes, Tom Curtis provided valuable contributions to this post. Dr. Pielke, the question we are addressing with this post is the CO2 (and net anthropogenic) contribution to the observed surface warming over the past century. In order to answer this question, we must examine the change in forcings over that period of time (not the remaining imbalance/unrealized warming, which is a separate issue). You have not identified any problems with our calculations of the CO2 contribution over the past century - namely accounting for your calculational errors and correcting values for the methane, ozone, and albedo forcings brings the CO2 contribution to the net positive radiative forcing over this period to ~50%. We also showed that CO2 caused ~0.79°C, and the net anthropogenic forcing caused ~0.65°C surface warming over the past century. We again ask if you now agree with these values (and the ranges for these values listed in the post above). The issues you raise regarding the CO2 contribution to the more recent radiative imbalance is a separate question, which does not affect the calculation of the total CO2 contribution over the past century. We can proceed to discuss this issue as well, but first would like to close the discussion on the human-caused warming over the past century.
72772. dana1981 at 07:07 AM on 11 October 2011
       Pielke Sr. and SkS Disagreements and Open Questions
       Dr. Pielke, the large ice sheets during the last glacial maximum formed as a consequence of the low global temperature. Attributing the temperature decrease to the presence of ice sheets and their geographical impact is circular logic. You are effectively arguing that the ice sheets formed due to the presence of the ice sheets. A climate sensitivity of ~3°C for doubled CO2 is a robust feature of the Phanerozoic Eon, across a very large range of continental distributions. Are you suggesting that changes in geographical distribution have mimicked the effect of a high climate sensitivity across all those distinct geographical distributions and time?
72773. Dikran Marsupial at 05:32 AM on 11 October 2011
       Understanding climate denial
       elsa As Sphaerica suggests, nobody has said that consensus advances science, it is the other way round, the consensus is the result of advances in the science reducing the key uncertainties to the point that (more or less) everybody is in agreement on the basics. Perhaps you should read "The Structure of Scientific Revolutions" by Thomas Kuhn. He basically argues that science proceeds via a sequence of paradigms, each of which represents the current mainstream view of the science of the day, which persists until the flaws in the current paradigm become overwhelming and there is a scientific revolution leading to a new (hopefully improved) paradigm. So according to at least one well known philosopher of science, the existence of a consensus is what you would expect to see once a paradigm has been established (i.e. the science is essentially settled - at least for the moment ;o). I'm not personally much of a fan of Kuhn, IMHO all scientific progress shifts mainstream view if only imperceptably and it is hard to define what size of shift is categorised as a paradigm shift and what isn't. However the point remains that the existence of a consensus is evidence of a stable paradigm (i.e. a mainstream view of the science that is essentially robust in which a fatal flaw has yet to be revealed. Skeptics often think they have driven the final nail into the coffin of AGW, but unfortunately they have usually just bashed their thumb).
72774. Bob Lacatena at 05:13 AM on 11 October 2011
       Understanding climate denial
       173, elsa,

       Scientific "consensus" is an odd way of advancing science.

       A strawman. No one ever said that consensus advances science. The point is that the scientists working actively in the field have reached a point where they all pretty much agree on what they understand and what it means. That happened simply because they all started to individually come to the same conclusions. They didn't get together and take a vote, or debate on a group position, or adopt it as a strategy. That's just what happens. After a while everyone starts to say "wait a minute, this is all starting to fit." That's called a consensus. The problem is that no one's ever before had to prove to legions of deniers that such a consensus does or does not exist. No one every really even thinks about it and says "aha, I think we have a consensus!" No, normally science just works. What you have now, however, are legions of deniers who don't know what they're talking about, don't want to either understand or accept the science, and who attempt to circumvent the science by manufacturing the illusion of doubt, and part of that illusion is to claim that there are a lot of reputable scientists who disagree with current climate science. There are only a handful, because there is in fact a consensus, which is the tangential result of everyone having done so much research that most of the pieces fit, and very few people question how they fit or what they mean.
72775. DSL at 05:08 AM on 11 October 2011
       Understanding climate denial
       Jonathan, that's an odd view. Most scientific work (advancement) is not "breaking through." Most scientific work is recognizing gaps in previous work (existing understanding) and working to fill those gaps. Most scientists do not go to work each day hoping to overturn the fundamentals of their disciplines. The scientific understanding of the world has become more and more precise over the last 200 years. That is true largely because scientists have been able to build carefully and methodically on the work of their predecessors rather than constantly re-writing the fundamentals. And it is not "individual" scientists doing this. Science is highly social, and major breakthroughs (not breaking through perceived boundaries but finally having the means to fill in a tough gap) occur through the work of often dozens of scientists. I can't remember the last time I saw a major study in the hard sciences authored by one individual. Your perceived moments of the individual Galileo are extremely rare. Most major changes to the fundamentals occur through individuals who work within schools of thought, schools that have developed for years with a core group of scientists. Finally, one can scarcely move a few centimeters through the history of science without tripping over failed schools of thought.
72776. Bob Lacatena at 05:07 AM on 11 October 2011
       Understanding climate denial
       173, elsa,

       ...they have the trappings of science but are in fact not scientific at all.

       Spoken clearly and unequivocally by someone who clearly does not understand the science well enough, or else you would not make such an outrageously false statement. I suggest you begin with Dr. Spencer Weart's The Discovery of Global Warming. When you have studied enough to understand what we do in fact know, how, and how well, then you can come back and correct your own mistaken post.
72777. CBDunkerson at 04:26 AM on 11 October 2011
       Understanding climate denial
       This looks like semantics and/or sophistry to me. Yes, science is advanced by research... but scientific advancements are recognized by consensus. Mendel did the research to advance science with the understanding of genetics... but nobody noticed until decades after he had died. Further research on genetics was stalled until the work was rediscovered and a consensus grew that it was correct and useful information.
72778. Albatross at 03:49 AM on 11 October 2011
       Pielke Sr. and SkS Warming Estimates
       I just want to recognize the important contribution made by Tom Curtis in preparing the above post.
72779. pielkesr at 03:42 AM on 11 October 2011
       Pielke Sr. and SkS Warming Estimates
       KR - I agree this scaling would be the same if all of the forcings had the same time evolution. When I discussed this with V. Ramanathan and others on our committee, however, the conclusion was that the other forcings ramped up more recently. In any case, what we really need is the current best extimate of the 2011 global-annual averaged radiative forcing and the best estimate of the 2011 global-annual averaged radiative imbalance. The difference between these two values is the global-annual averaged radiative feedback.
72780. pielkesr at 03:39 AM on 11 October 2011
       Pielke Sr. and SkS Warming Estimates
       KR- My question remains, what is the current radiative forcing of CO2? In the SPM for the IPCC 2007 report, with respect to their presentation of the values in their figure SPM.2 they write "Global average radiative forcing (RF) estimates and ranges in 2005 for anthropogenic carbon dioxide (CO2 ), methane (CH4 ), nitrous oxide (N2O) and other important agents and mechanisms, together with the typical geographical extent (spatial scale) of the forcing and the assessed level of scientifi c understanding (LOSU)." They specifically state "Global average radiative forcing (RF) estimates and ranges in 2005". Then in footnote #2, they write "In this report, radiative forcing values are for 2005 relative to pre-industrial conditions defined at 1750 and are expressed in watts per square metre (W m–2). " At the best, this was sloppy writing (as it is corrected/clarified in the footnote), but the figure caption itself is misunderstood by quite a few people. At worst, the writers were not clear oo this when they wrote the figure caption. In any case, what would SPM.2 look like for the current forcings?
72781. KR at 03:33 AM on 11 October 2011
       Pielke Sr. and SkS Warming Estimates
       Dr. Pielke - Minor addition to my previous comment: If you are looking at unrealized warming and remaining imbalances (rather than the changes since 1750 that are the topic of this thread), it's noteworthy that you cannot just scale the change in CO2 contribution - all radiative imbalances scaled by unrealized warming would be scaled as well, meaning that the relative contribution of CO2 should not change. Your 20% reduction of relative CO2 contribution is, again, not justified in my view.
72782. Jonathon at 03:24 AM on 11 October 2011
       Understanding climate denial
       Michael. I disagree. Science does not advance by consensus. Consensus (if it occurs) is one of the last steps in advancing science, and only occurs after much scientific work has been performed. Science advances by individual scientists breaking through previously perceived boundaries to make new discoveries. Oftentimes, these scientists are ridiculed by their peers for proposing such "ridiculous" theories. These theories go against the established scientific tenets (consensus), and require sufficient proof to convince the scientific establishment. Look at history, how many scientific theories were advanced by consensus? Consensus is for bureaucrats and politicans. Science advances by research and evidence. I side with Elsa on this one.
72783. KR at 03:24 AM on 11 October 2011
       Pielke Sr. and SkS Warming Estimates
       Dr. Pielke - "You also did not discuss that CO2 has been increasing for over a century and some of the CO2 radiative forcing during that period would have been accomodated by the warmer climate. As I wrote, in 2005 V. Ramanthan replied to me (in an estimate) that about 20% of the difference between pre-industrial and current radiative forcing would have been accomodated. Thus the current radiative forcing from added CO2 would need to be reduced by this amount." I would have to strongly disagree - the radiative forcings discussed here (as in the IPCC AR4, the basis of this discussion) are relative to 1750 pre-industrial forcings, not the current imbalance (unrealized warming) between temperatures and those forcings. The 20% adjustment you recommend here is an odd (and IMO quite unwarranted) redefinition of well understood terms - shifting the baseline. Unrealized warming and current imbalance are different terms, different values, than forcing changes since 1750.
72784. DSL at 03:14 AM on 11 October 2011
       Understanding climate denial
       Elsa, climate modeling is an attempt to forecast climate based on a sound physical model and probable conditions. It is the equivalent of Doll saying, "Smoking will continue to cause premature deaths in smokers at a rate of 75 per 100 over the next 100 years." His work was not predictive, or, if it became predictive, it would have the same basic weakness of all models of real world phenomena: the unknown. Yet science is pointless without such predictive applications (as Doll notes through the act of quitting smoking). Climate, as you say, is extraordinarily complex, and it must include the human element, so it becomes even more complex. Does that necessarily mean that it should not be done or that it is currently being done poorly? No. Many of the models are actually quite good. Note that you offer a range of between 0C and 4C, but you do not give the model confidence for any values in this range. This suggests you haven't studied climate modeling. Yet you make absolute statements about the activity. If you have questions, ask them. Further comments on modeling should be posted to the appropriate threads. Use the search function for "models" -- there are quite a few threads on the subject. Oh, and there has been a great deal of work done recently on causes of genetic mutation in smokers. See this study in Nature.
72785. pielkesr at 02:52 AM on 11 October 2011
       Pielke Sr. and SkS Disagreements and Open Questions
       CBDunkerson - I am proposing that now that we have good ocean heat data coverage, we move towards replacing the global annual average surface temperature trend as the primary metric to diagnose global warming. Certainly 7 years is not sufficient but will be as the years pass. Since the models predict (project) how this ocean heat should change, we can track their skill and set up requirements for them to be considered skillful with this metric.
72786. michael sweet at 02:52 AM on 11 October 2011
       Understanding climate denial
       Elsa: Ask Dr. Lindzen (the well known climate denier) about the link between smoking and cancer: he claims there is no data to support it. One of the past Presidents of South Africa denied that HIV caused AIDS. Gravity theory has been challenged in the last few decades (check alternative gravity versus dark matter theories). If you do not pay attention to scientific developments you are not aware of what is current. All science advances by consensus. If you learn more about science you will realize that is the way science works. How much of this site is dedicated to modeling? Learn more about the data that supports climate science and you will lament models less.
72787. pielkesr at 02:46 AM on 11 October 2011
       Pielke Sr. and SkS Warming Estimates
       dana1981 & Albatross Thank you for the detailed analysis. I have several comments: 1. NRC (2005)- see http://www.nap.edu/openbook.php?record_id=11175&page=40 concluded that several aerosol effects were positive. I chose the nominal value of +0.1 Watts per meter squared. I agree these are uncertain, but conclude we do not know more about them in 2011 than we did then. A review paper on this specific topic would be quite informative. 2. I can accept your conclusion of double-counting and use the ~32% value. The 4% difference is certainly within the envelope of uncertainty in any case. If you then start from the 52.4% value that you list from IPCC AR4, our improved understanding of the role of black carbon (in the atmosphere and at the surface) and the other aerosol effects, this will reduce this value. We seem to be in agreement that the black carbon positive radiative heating is larger than assumed previously. This has already reduced the contribution to 48.2% in your value for Skeie (2011). If we use the 0.9 Watts per meter squared value for the black carbon that you present,from the Ramanathan and Carmichael (2008) values and the 0.2 Watts per meter squared as reasonable estimates based on the NRC (2005) report, which is still an accurate summary of our limited knowledge of this forcing, I calculate that CO2 is ~40% for the anthropogenic positive radiative forcing. This accepts the values for ozone that are listed in your table. The CO2 forcing, to my knowledge, does not consider humid regions, such as the tropics, where existing water vapor reduces the effective radiative forcing due to the CO2 by itself. If this is not included, it would reduce the radiative forcing fraction from CO2 further. Please clarify. 3. You also did not discuss that CO2 has been increasing for over a century and some of the CO2 radiative forcing during that period would have been accomodated by the warmer climate. As I wrote, in 2005 V. Ramanthan replied to me (in an estimate) that about 20% of the difference between pre-industrial and current radiative forcing would have been accomodated. Thus the current radiative forcing from added CO2 would need to be reduced by this amount. The other positive radiative forcings, being more recent presumably are not reduced as much. As an estimate, we use a 20% reduction for the CO2 forcing, this lowers the fraction of positive radiative forcing from CO2 to ~35% of the anthropogenic radiative forcing. This is still a back of the envelope calculation and I have proposed the following in my weblog post 1. Use a column radiative transfer model (for all wavelengths - i.e. short and long wave) on a vertical profile of temperature, humidity and clouds at a sufficient number of locations (grid points) around the world (using all global reanalysis grid points) during a year (with hourly time intervals) to determine the baseline current radiative forcing. If resouces permit, do more than one year. Calculate the global average radiative forcing by integrating over the year at each grid point. While radiative feedbacks, of course, are implicit in the vertical profiles, the radiative transfer model provides the instantaneous forcing at that time. 2. Use the column radiative transfer model with these same soundings but [sensitivity test #1] change the CO2 level back to pre-industrial, [sensitivity test #2] change the aerosol load back to preindustrial, [sensitivity test #3] change the land cover back to natural, etc and express the values in Watts per meter squared. 3. For each of these sensitivity tests, sum up the differences in radiative forcings to obtain the global annual average in Watts per meter squared. The important conclusion, in my view, is that added CO2 is a substantial positive radiative forcing but that it is not currently (or in the past) been the majority of positive radiative forcing. We agree that it will be increasing its fractional contribution in the future and certainly could become the majority if the aerosol input were eliminated. 4. However, in your take-home message, you have not answered my question in my weblog post with respect to the following: "My question back to Skeptical Science, is to present your perspective on this issue. How would you propose including the assessment of the effect of each of the human climate forcings in terms of their effects on regional atmospheric and ocean circulations (i.e. by altering the pressure gradients through diabatic heating due to the radiative heating/cooling from CO2 and the other greenhouse gases, aerosols and land use/land cover change? I recommend as a starting point for discussion on this issue, our paper Matsui, T., and R.A. Pielke Sr., 2006: Measurement-based estimation of the spatial gradient of aerosol radiative forcing. Geophys. Res. Letts., 33, L11813, doi:10.1029/2006GL025974. http://pielkeclimatesci.files.wordpress.com/2009/10/r-312.pdf The abstract reads "This paper diagnoses the spatial mean and the spatial gradient of the aerosol radiative forcing in comparison with those of well-mixed green-house gases (GHG). Unlike GHG, aerosols have much greater spatial heterogeneity in their radiative forcing. The heterogeneous diabatic heating can modulate the gradient in horizontal pressure field and atmospheric circulations, thus altering the regional climate. For this, we diagnose the Normalized Gradient of Radiative Forcing (NGoRF), as a fraction of the present global heterogeneous insolation attributed to human activity. Although the GHG has a larger forcing (+1.7 Wm-2) as measured than those of aerosol direct (-1.59 Wm-2) and possible indirect effect (-1.38 Wm-2) in terms of a spatially averaged top-of-atmosphere value, the aerosol direct and indirect effects have far greater NGoRF values (~0.18) than that of GHG (~0.003)." What is the SkS response to this perspective? In terms of how weather patterns are affected, in my view, heterogenous radiative forcings are much more important than the global average radiative forcing. I would like to see you discuss this issue. 5. In your take-home message, you also still have not answered the question as to what is the current (2011) positive radiative forcing? Also, what is total current radiative forcing and the current radiative feedback? 6. In answer to your question "Approximately what percentage of the global warming (increase in surface, atmosphere, ocean temperatures, etc.) over the past 100 years would you estimate is due to human greenhouse gas emissions and other anthropogenic effects?" please see figure 11 with respect to surface land temperatures in Pielke Sr., R.A., A. Pitman, D. Niyogi, R. Mahmood, C. McAlpine, F. Hossain, K. Goldewijk, U. Nair, R. Betts, S. Fall, M. Reichstein, P. Kabat, and N. de Noblet-Ducoudré, 2011: Land use/land cover changes and climate: Modeling analysis and observational evidence. Wiley Interdisciplinary Reviews: Climate Change, Invited paper, in press. http://pielkeclimatesci.files.wordpress.com/2011/09/r-369.pdf where we show how important is land use/land cover change. If one accepts the model results [although this, of course, does not include aerosol effect and natural forcings and feedbacks), about one half of the trends over land can be explained by land use change - where the effect is to reduce the warming effect from the CO2. Other studies, e.g. see Marshall, C.H. Jr., R.A. Pielke Sr., L.T. Steyaert, and D.A. Willard, 2004: The impact of anthropogenic land-cover change on the Florida peninsula sea breezes and warm season sensible weather. Mon. Wea. Rev., 132, 28-52. http://pielkeclimatesci.wordpress.com/files/2009/10/r-272.pdf suggests that land use change dominates surface temperature in that region but in this case there is a positive temperature effect from the land conversion. My bottom line summary: 1. We both agree that the radiative forcing of added CO2 is an important climate forcing. While we disagree on its fractional contribution at present, we both agree this fraction will become larger in the future (as will its biogeochemical forcing). It is also a long lived change to the composition of the Earth's atmosphere, and thus its reduction (removal) is a duanting challenge. My son, in his book The Carbon Fix, discusses carbon capture directly from the atmosphere as one possible option. However, other climate forcings are also long-lived. This includes land use/land over change, and nitrogen deposition. Both will influence atmospheric processes. For a sobering view of how much we are altering the climate system from nitrogen deposition, see slide 12 in http://pielkeclimatesci.files.wordpress.com/2011/09/ppt-121.pdf 2. The positive radiative forcing from soot (black carbon) in the atmosphere and at the surface is larger than assumed in the past. The radiative forcing from other aerosols remains uncertain but several of the effects are considered by some to be positive and significant. 3. From a policy perpsective, our debate is essentially irrelevant. We both agree that permitting atmospheric concentrations to increase risks consequences. Where we disagree is i) I have concluded it is the biogeochemical forcing of added CO2 that is the larger concern with respect to the CO2, and ii) human-added CO2 is a first order climate forcing but is not the only first order human climate forcing. In terms of what matters most to society and the environment, the more heterogenous climate forcings (both in terms of regional radiative forcing and non-radiative effects) should be elevated in concern. This later view is of policy relevance as Mike Hulme has written on (see slide 71 in http://pielkeclimatesci.files.wordpress.com/2011/09/ppt-121.pdf) Thank you for the opportunity to now debate in a constructive manner.
72788. michael sweet at 02:43 AM on 11 October 2011
       It's not bad
       I have visited Tuvalu. The situation there is terrible. They had a very traditional lifestyle and are really friendly people. I still have two grass hula skirts they gave me. The people there have few options besides migration. Your link says that Australia turned down a Tuvaluan proposal for migration. Who will take them in? Increased waves from stronger storms (caused by AGW) have combined with sea level rise to poison most of their fresh water. Your link says Samoa is also rationing water. Samoa is a much larger country with much greater land mass. It must be a serious drought for Samoa to be running short of water.
72789. elsa at 02:38 AM on 11 October 2011
       Understanding climate denial
       Scientific "consensus" is an odd way of advancing science. We do not talk about such a thing when we discuss gravity, we know the theory can be tested and has yet to be proved wrong. No-one seriously doubts it. The same applies to HIV and AIDS. There is a virus, it can be identified and no-one(so far as I know) suggests that people have contracted AIDS without the HIV being present. Smoking and lung cancer is a bit different because we do not yet have a perfect explanation about how smoke causes cancer. Here there may be a consensus about the mechanism but the evidence is not yet all in, as far as I know. We can say that if you do not smoke you are very unlikely to develop lung cancer, but we cannot say that absolutely all people who develop lung cancer are smokers. The statistical correlation between lung cancer and smoking was however very strong. When Sir Richard Doll started to investigate the rise in lung cancer rates in the UK he found that of his 700 cases 698 were smokers and, as a result, he gave up smoking while conducting his investigation. All of these cases are in sharp contrast to the case of man made global warming. Unfortunately climate is a complex business and does not lend itself to easy explanations. The evidence is not remotely overwhelming and is unlikely to become so because there are so many possible influences on climate that no possible way exists of disentangling the effect of each factor. The claims that we know that if the CO2 concentration increases by 100% the world will warm by 2C or 3C or 4C or not at all are what would be labelled in other areas as "scientistic", that is to say they have the trappings of science but are in fact not scientific at all. To compare the fantastic work of Sir Richard Doll with the pseudoscience of climate modelling is a disgrace to his memory.
72790. DSL at 01:50 AM on 11 October 2011
       Book review: The Inquisition of Climate Science
       For those who want another look into the minds of US conservatives, you might check out the NYTimes review of Corey Robin's The Reactionary Mind here. Keep in mind that the reviewer is thoroughly middle-class liberal (Barnard College political scientist). Robin's reply to the review is here. The response is, for me, more enlightening than the review, but both speak to what has been said on this stream and others at SkS. critical mass, I'm not sure what you mean by "effectively." Could you characterize the exchange for us (on the appropriate thread)?
72791. Jeffrey Davis at 01:48 AM on 11 October 2011
       Pielke Sr. and SkS Warming Estimates
       I think there's a weird kind of thinking that can flow from the fractioning of various influences to global warming. Since CO2 is the main culprit, it has become a kind of stand-in for all human contributions. So, if you diminish the role of CO2 you can pretend that it really isn't that big a deal. But soot is also significant contributor and all too human in its provenance. Fix one (clear coal out of our energy production) and you can go a long way to fixing both. But our carbon-extraction overlords have pointedly gone out of their way to make sure we don't address either. Any thing and everything can be used to make delay seem a viable alternative.
72792. pdt at 00:55 AM on 11 October 2011
       Imbalance in US TV Media Coverage of Greenhouse Gas Regulation
       I'm not sure if anyone reads this or even cares, but I just read the book "Earth: the Sequel" which strongly argues for Cap-and-Trade. This made me consider this more deeply and answer some of my own questions, stated above. There are some very big differences between regulations for CO/NOx/soot from vehicles and regulation of CO2 which I think make Cap-and-Trade a better solution than straight regulation. The most obvious is that fossil CO2 emissions come from a wider array of sources, some of which have a very long lifetime. For NOX/CO/soot, regulations are put in place and the vehicle fleet essentially turns over in 10 years, solving the problem. Regulations for CO2 would be much more complex to implement in order to be effective. Still, the effectiveness of Cap-and-Trade will depend greatly on the details of implementation. It also will not come without downsides, such as speculation in the carbon markets causing uncertainties in prices. We have been reminded rather brutally recently of the issues with markets. So far I haven't heard of a better solution though.
72793. Eric (skeptic) at 00:23 AM on 11 October 2011
       Pielke Sr. and SkS Disagreements and Open Questions
       Tom, no argument that there is a lot of feedback from several sources needed to create a hysteresis, one of which is CO2. The other large feedback besides albedo, as suggested by Dr. Pielke, is weather. The problem comes when trying to ascertain the warming contribution of albedo feedback, CO2 feedback and weather feedback. Ice albedo being responsible for the hysteresis does not simplify the calcuation. There are, in short, two ways to do it. Extremely crude energy balances that ignore the changes in weather and produce results between 1 and 6C (Knutti 08) or models which must not only have parameterized weather but parameterized paleo weather. Neither method produces anything more than a guesstimate.
72794. critical mass at 00:15 AM on 11 October 2011
       Book review: The Inquisition of Climate Science
       If anyone is searching for a 'thoughtful skeptic' there is a very interesting and civil discussion going on at Real Climate under the thread title "Global Warming and Ocean Heat Content" in which Dr Roger Pielke Snr is engaged with several participants who are questioning Gavin Schmidt rather effectively.
72795. DSL at 00:13 AM on 11 October 2011
       It's not bad
       It seems bad for Tuvalu. The Economist, likening the situation to a "canary in a coal mine," reports that Tuvalu is both running out of fresh water and beginning to suffer from sea level rise.
72796. Harald Korneliussen at 00:09 AM on 11 October 2011
       Book review: The Inquisition of Climate Science
       The misinformers link is a bit cluttered. I think it would be a good idea to distinguish between people with climate science credentials (e.g. Lindzen and Spencer), scientists in related fields, and out and out ideologues who rely on the former groups for ammunition (Ron Paul, Christopher Monckton, Anthony Watts etc.) Producers and consumers, so to say. Sourcewatch does a good job on these people, but hardly presents it in a way that's useful for convincing people. It would also be useful if the more honest misinformers, those who have objections to the consensus that can actually be articulated scientifically get such views presented briefly there, ideally in a way they wouldn't object to (e.g. "Pielke Sr. believes the radiative forcing from methane is far higher than is generally accepted").
72797. Tom Curtis at 23:17 PM on 10 October 2011
       Pielke Sr. and SkS Disagreements and Open Questions
       Eric (skeptic) @41, Calov and Ganopolski 2005 argues that NH summer insolation alone is not sufficient by itself to explain the transition between glaciated an non-glaciated states. Fairly obviously, nobody disagrees with that. The difference in albedo between glaciated and non-glaciated state makes an important difference. Importantly, nothing Calov and Ganopolski show suggests that anything other than this change in albedo is the cause for the hysteresis. That being the case, the hysteresis they find is not bar to determining the climate sensitivity of CO2 so long as changes in albedo are treated as a forcing, not a feedback. That is what Hansen has done, so no issue arises.
72798. CBDunkerson at 23:16 PM on 10 October 2011
       Pielke Sr. and SkS Disagreements and Open Questions
       Dr. Pielke, isn't there a logical inconsistency in suggesting that 7 years is sufficient time to determine a long term trend for upper ocean heat content? How can that be true when different 7 year periods show radically different trends? If 2003-2009 is sufficient to establish a trend of only slight warming why wasn't 1997-2003 (or various other earlier periods) sufficient to establish a more pronounced warming trend? Unless you are suggesting that some major climate forcing has recently changed to a new state which will remain stable for a prolonged period the position seems inherently insupportable. There have been significant trend variations for longer than seven years in the heat content estimates before now. Logically that would seem to indicate that a longer period is needed to screen out data fluctuations and determine the long term trend. Would you be arguing that upper ocean heat content had established a clear long term trend and should serve as the primary (sole?) 'measuring stick' for climate change if we were back in 2003 with only the data available up to that point? Obviously that would have pointed to completely different conclusions than focusing on the past several years does... so either the underlying trends have suddenly changed for some reason or the position is not internally consistent.
72799. John Russell at 22:56 PM on 10 October 2011
       Understanding climate denial
       Here's some interesting news relevant to this discussion of denial. I'm sure we've all come across people who, seemingly illogically, just refuse to consider negative evidence; as if they have some sort of mental block. It seems it might have a basis in brain function.
72800. elsa at 22:18 PM on 10 October 2011
       Book review: The Inquisition of Climate Science
       However, Powell points out one distinction between the Roman Inquisition and the modern day Climate Inquisition. At least the Roman inquisitors had an alternative theory - Ptolemy's 2nd Century theory of Earth-centered astronomy. The Climate Inquisition have no alternative theory that can explain the many lines of evidence that point to human caused global warming. I am not sure why you say "at least". You seem to assume that it is better to have a theory, no matter how wrong, than to have no theory at all. This is a bit like arguing that doctors in the middle ages who attributed disease to bad humours should not have been criticised for their rubbish views because there was no better explanation available at the time.

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