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Comments 110501 to 110550:

110501. johnd at 08:32 AM on 10 September 2010
        Climate change: Water vapor makes for a wet argument
        Phil at 23:33 PM, you've got it all back to front. You being the bread winner puts in $168, as this is where all the money consequently saved or squandered originates from. The question then becomes do you first pay out on priorities such as utilities, $78 and food, $24, which ultimately are all forms of heat energy, leaving you to find $390 to pay your credit card bill, usually done by drawing a cash advance of $324 to make up the difference. As to who contributes how much for the presents, you would have to examine your credit card statement to find out that given $40 went as interest, you are left with nothing for presents. There must be some interesting discussions at your house each pay day. ;-)
110502. NETDR at 08:27 AM on 10 September 2010
        Pielke Sr and scientific equivocation: don't beat around the bush, Roger
        RE: J Murphy 91 Catastrophic AGW is what it sounds like. [CAGW] Human caused warming with consequences so dire that we must take actions which will damage our economy seriously to avoid it. This is to distinguish it from simple AGW which may or may not be true but is a scientific not a political question. If the temperature will rise 6 ° C in 100 years the prudent action would be different from that taken if the temperature were to increase 1 ° C in 100 years. Many people, like myself, believe CO2 is a GHG and we are emitting CO2 so we must be causing some warming. In that respect we believe in some AGW but not in raising energy prices so high we damage our economy and sending jobs overseas where ironically it would increase CO2 emissions. Shoot ourselves in the foot and complain about the pain ? Develop alternate energy, that is obvious. Remove soot too. Wreaking our economy makes no sense unless CAGW is real and imminent. Without positive feedbacks CO2 will only cause 1 ° C for a doubling in 100 years. Which is no crisis. The sense of crisis comes from models which amplify this tiny warming by purported positive feedback which starts tomorrow.
110503. johnd at 08:08 AM on 10 September 2010
        Climate change: Water vapor makes for a wet argument
        MattJ at 08:37 AM, I agree entirely with you. The diagram is a rather simplistic depiction of the energy budget, and as with all budgets has to be twigged to balance. What is doesn't do is represent the order of the processes and which processes may have priority over others. That is if heat is being transferred, which process facilitates a slow transfer and which may ramp up as the rate increases and are able to handle excess amounts of energy. Which may ramp up as others are ramping down, still maintaining the nett balance. Earlier on I asked for what I termed a critical path chart. That was using terminology from another discipline and I'm not sure whether such a depiction even exists for this subject of heat transfer given it was only the energy budget diagram that was presented. When solar energy is absorbed by water, I believe that evaporation occurs first and only any excess energy is absorbed by the body of water, thus the evaporation process is primarily a function of direct solar radiation and secondarily of the thermal energy that is stored in the body of water. This can be readily observed in practice where water that is open to the atmosphere AND in direct contact with solar radiation evaporates at a far greater rate than water that is also open to the atmosphere but shaded from direct solar energy. In the case of water being heated by any form of heat, even a immersion heater, as the temperature of the water rises, evaporation and the radiation off of heat both occur, however as the water reaches boiling point it becomes clear that the ultimate determinate of how much heat the water is able to absorb is not the radiating off of heat, but the evaporation process. When the day comes that an equivalent to a solar hot water heater has been developed that works by passively absorbing back radiation, then perhaps we can revisit the topic again from a new perspective.
110504. Rob Painting at 08:03 AM on 10 September 2010
        Pielke Sr and scientific equivocation: don't beat around the bush, Roger
        KL @ 81 - "Dr Pielke should clarify this point and perhaps comment on my suggested 'ideal' gold standard OHC measurement system of globally tethered buoys all reporting at the same time." Seriously KL, do you think buoys tethered to the deep ocean floor has not already been suggested by the experts?. Future observations for monitoring global ocean heat content Note the names that appear at co-authors, they should sound familiar: M. Palmer , J. Antonov , P. Barker 3, N. Bindoff , T. Boyer, M. Carson,, C. Domingues, S Gille P Gleckler, S. Good, V. Gouretski, S. Guinehut, K. Haines, D. E. Harrison,, M. Ishii G. Johnson, S. Levitus, S. Lozier, J. Lyman, A. Meijers, K. von Schuckmann, D. Smith, S. Wijffels and J. Willis. "In order to close the energy budget of the Earth’s climate we must move to an observing system capable of measuring the global ocean in its entirety. Despite the improved data coverage associated with Argo, the deep (> 2000m) and ice-covered ocean remain largely un-observed. Currently, the only full-depth ocean observations come from the dedicated hydrographic cruises, which can only sample a very small area of the deep ocean. In the future, these hydrographic cruises must be augmented by an array of deep floats, moored instruments, gliders, or a combination thereof to allow a true global integral of ocean heat content from the surface to the sea floor."
110505. scaddenp at 07:23 AM on 10 September 2010
        The Little Ice Age: Skeptics skating on thin ice
        Daniel, I have to disagree with you on this one about evidence for LIA as a global event. MWP wasnt but I think there is pretty good evidence that LIA was. (eg High-Frequency Holocene Glacier Fluctuations in New Zealand Differ from the Northern Signature
110506. DrTom at 07:14 AM on 10 September 2010
        Pielke Sr and scientific equivocation: don't beat around the bush, Roger
        Aloha All. Oceans and landmasses, including mountains are, to the earth, roughly equivalent to the thickness of the skin of an apple. Physical measurement...each smaller at scale than an atom of that skin, or even the gross measurements available from extant satellites cannot always provide sufficient information to make arguments unequivocal - which is why there is a disagreement. Haloclines and thermoclines are continuously variable. The oceans are dynamic. Whether we understand our planet sufficiently to be able to say we are 'missing' heat seems to beg the question: Do we now know everything to a sufficient degree to be able to make that assertion, or is it more likely that we are missing a connection somewhere? We shouldn't need to frame our arguments around this level of specificity. We can look for connections outside our disciplines to guide us. I suggested a non-specific hypothesis to my post-doc group in response to a peak-oil question here: http://drtom.posterous.com/is-there-anything-we-can-do-about-peak-oil-an Warning: I use that blog to vent and nothing is sacred to me. Wandering past that particular post will almost certainly land you somewhere you don't want to be. For the sanity of those who do not want to take the chance, here is the nutshell version: Every degree of atmospheric warming increases the amount of water vapor by ~5% which directly affects the hydrological cycle which directly affects everything else on the planet. The increased water vapor is not measurable everywhere because the atmosphere is dynamic as well. But that doesn't mean it is missing. The effects are certainly observable. The weather is changing rapidly and radically. Like Morton salt used to advertise, "When it rains, it pours". Hurricanes are now much more likely to be category 5 than ten years ago. That is not because anything is missing. It is because something has been added. In a possibly unrelated event, someone must have put WAAAAY too much Fluoride in the D.C. water supply because a lot of people there are getting wonky too. (sorry) I don't care whether anyone finds the missing heat. One second of rational thought tells us that nothing is 'missing'. Simply because we cannot find what we think should exist in the place we expect to find it does not make the case for 'missing' - unless the case is for missing knowledge. Physical laws are not always complete but they don't go missing. I care that the improperly framed 'missing' argument is being extrapolated to 'prove' two different conclusions, both based upon insufficient data. Let us cut to the chase. The biosphere is warming. Therefore the oceans are warming. We are entering a rapid-onset warming event which will manifest itself in years, not decades. Past rapid-onset warming events have ALWAYS become mass-extinction events. What if this one is too? We can only prepare for it if we accept the possibility it can occur. This is like no other time in terrestrial organic history. We can err the right way and lose nothing but we can no longer argue that we have time left. We are out of time. The weather has already changed - we are no longer 'forcing' it. We are off that cliff already. The arctic will be ice-free by 2020. That ice is already floating so the sea level won't rise. But it is melting for a reason.
110507. RobertS at 07:12 AM on 10 September 2010
        How we know the sun isn't causing global warming
        I realize my #2 is oddly worded. I guess my brain got ahead of my fingers... 2) Even if a periodic component does exist (solar or otherwise), its magnitude must be so small as to render it nearly undetectable considering many "cycles" were missed altogether during the last glacial, and so-called Bond events are virtually nonexistent in the temperature record. Several authors (Rahmstorf, Alley, Ganopolski) argue for the use of stochastic resonance in modeling D-O events, whereby this very weak signal is greatly amplified by noise in the system to push the climate over a particular threshold in a glacial state.
110508. Albatross at 06:44 AM on 10 September 2010
        Pielke Sr and scientific equivocation: don't beat around the bush, Roger
        Current global sea-level data:
110509. John Hartz at 06:33 AM on 10 September 2010
        Pielke Sr and scientific equivocation: don't beat around the bush, Roger
        On the lighter side... If I tell someone that he/she is only human, is that an "ad hominem" comment?
110510. Roger A Pielke Sr at 06:30 AM on 10 September 2010
        Pielke Sr and scientific equivocation: don't beat around the bush, Roger
        CBW - It is good that there are now weblogs so that misstatements such as you have made can be refuted. You write 1. "Pielke claims that ARGO presents accurate instantaneous snapshot of OHC, despite ARGO saying it doesn’t" First, I have never used the term instantaneous" in this context. Since ocean heat changes relatively slowly on larger scales, time slices can use monthly averages, for example. In the context of the robustness of the OHC data, below is what Josh Willis wrote to Kevin Trenberth, as I reported in my weblog post Further Feedback From Kevin Trenberth And Feedback From Josh Willis On The UCAR Press Release http://pielkeclimatesci.wordpress.com/2010/04/19/further-feedback-from-kevin-trenberth-and-feedback-from-josh-willis-on-the-ucar-press-release/ "Hi Kevin, I’m not sure why you think that the analysis methods of recent ocean heat content estimates are not robust. Since about 2005, most any analysis method that makes use of the Argo data should get approximately the same answer, which is that there is little net warming over this period. In fact, I have verified that my estimate compares well with Karina’s between 2005 and the end of 2008, even though she integrates to 2000 m and I only integrate 900 m. In the early part, however, the von Schuckmann analysis is problematic because it definitely contains some Argo data that still had pressure biases, and because they relied on a climatological background field that was probably too cold. Because the early part of the Argo record (pre-2005) has large gaps, their analysis relaxes toward the cooler climatology in the early part of the record. This has the potential to make the global trend appear larger than it may actually be. Without cleaned up Argo and/or XBT data with reduced biases, I do not belive that we can actually say that the satellite data in recent years are more reliable than the ocean heat content estimates." 2. "Pielke denies that any substantial mixing with deeper ocean could have occurred during those 4 years despite evidence that 2000m trend differs from the 700m trend, and despite a very incomplete human understanding of total ocean circulation." This is what Josh Willis wrote as I reported in my post Further Feedback From Kevin Trenberth And Feedback From Josh Willis On The UCAR Press Release. http://pielkeclimatesci.wordpress.com/2010/04/19/further-feedback-from-kevin-trenberth-and-feedback-from-josh-willis-on-the-ucar-press-release/ "Hi Kevin and Roger, Incidentally, you two might be interested in this recent paper by Sarah Purkey and Greg Johnson: http://www.pmel.noaa.gov/people/gjohnson/Recent_AABW_Warming_v1.pdf They looked at the prospect of deep warming on decadal time scales using the sparse, but highly accurate repeat hydrographic sections and found that below 3000 m in the global oceans, and below 1000 m in the southern ocean, the ocean is taking up an energy equivalent of about a 0.1 W/m^2 energy imbalance at the top of the atmosphere. So while this is significant, it suggests to me at least that the deep ocean is probably not taking up a bunch of heat really rapidly and the traditional idea that most of the action is in the upper several hundred meters is probably going to hold up. (did I get that right, Greg?) Cheers, Josh" 3. "Pielke rejects other evidence, particularly sea level data, that OHC continued to increase unabated." Regarding sea level rise, it has reduced in recent years, according to the peer reviewed paper below. Moreover, the rise that has occurred is not from thermal expansion (i.e. the steric component). Cazenave et al. Sea level budget over 2003-2008: A reevaluation from GRACE space gravimetry, satellite altimetry and Argo. Global and Planetary Change, 2008; DOI:10.1016/j.gloplacha.2008.10.004 they write "From the results presented in this study, we see that confronting independent estimates of ocean and land contributions to sea level with altimetry results leads to a rather coherent picture for recent years variations. This can be summarized as follows: since 2003, sea level has continued to rise but with a rate (of 2.5 +/-0.4 mm/yr) somewhat reduced compared to the 1993-2003 decade (3.1+/-0.4 mm/yr). Over 2003-2008, the GRACE-based ocean mass has increased at an average rate of ~1.9 mm/yr (if we take the upper range of possible GIA corrections as recommended by Peltier, submitted for publication)......The steric sea level estimated from the difference between altimetric (total) sea level and ocean mass displays increase over 2003-2006 and decrease since 2006. On average over the 5 year period (2003-2008), the steric contribution has been small (on the order of 0.3+/-0.15 mm/yr), confirming recent Argo results (this study and Willis et al., 2008).” I discuss this is my post Sea Level Budget over 2003–2008: A Reevaluation from GRACE Space Gravimetry, Satellite Altimetry and Argo by Cazenave et al. 2008. http://pielkeclimatesci.wordpress.com/2009/01/07/sea-level-budget-over-2003%e2%80%932008-a-reevaluation-from-grace-space-gravimetry-satellite-altimetry-and-argo-by-cazenave-et-al-2008/
110511. Jim Prall at 06:25 AM on 10 September 2010
        Ocean acidification isn't serious
        They seem to be relying on a simplistic reading of the terminology, where "only pH below 7 is 'acidic'" to support a serious fallacy--that by implication, any pH over 7 must be fine, even if it is falling fast The problem is that any significant change in pH affects biological systems and the solubility of the basic building blocks like CaCO3. There is no magic threshold at pH = 7.0 other than a semantic one; for a biochemist, nothing special happens crossing that line. Changing pH from, e.g. 8.3 to 8.2 has a real, tangible effect on the solubility of CaC03, and on the equilibria between CO2(aq), H2CO3, and HCO3[-1]. These changes alter the "saturation horizon"--the depth at which CaCO3 is saturated, and that has a vital effect on organisms that form hard carbonate shells. There are ecological impacts to any substantial change in pH, whether the starting point is 8.3, 7.9, or 7.001. Arguing that lowering pH substantially "isn't acicification" is just debating semantics, and certainly walks and quacks like a diversion tactic. If we need some evidence that working oceanographers don't have a problem with calling current changes from 8.3 to 8.2 "acidification," we need look no further than the Monaco Declaration on Ocean *Acidification* signed by 155 experts in the field: http://www.ocean-acidification.net
110512. eveningperson at 05:23 AM on 10 September 2010
        The Little Ice Age: Skeptics skating on thin ice
        The anecdotal evidence about frost fairs in London is very charming, and a staple of 'sceptic' discourse, but if the Wikipedia entry is to believed the river froze over significantly only a few times a century and that is counting winters when it 'more or less' froze over so presumably would not have supported people, stalls and games. And a painting is cited as if it were evidence of a commonplace phenomenon, when it is at least as likely that it was painted because the scene was so unusual and therefore worth commemorating. Other rivers in southern England have also frozen over, the Severn for example ca 1883 and possibly also in the 20th century (I'd really like to find some comparative figures). What happened with the Thames in the 19th is that the old London bridge, with its narrow arches that restricted flow, was demolished, and also the river was given embankments and made much narrower. So not only does it flow faster now but it presumably is more saline that it used to be in the stretch that froze over (it is tidal way above central London). One of the things about many sceptics (Watts notably) is that they are shameless in their use of anecdotal evidence, exactly like homeopaths and other pseudomedicine practitioners.
110513. KR at 05:20 AM on 10 September 2010
        Pielke Sr and scientific equivocation: don't beat around the bush, Roger
        MrJon - Your phrasing here is excellent, and captures the realities of the data uncertainties. It won't tweet well, sadly, but it's excellent. I recall part of Steve Schneider's last TV appearance, talking to a room of climate skeptics, where he discussed scientific credibility. He stated: "Anybody who's got the answer almost certainly is not credible on a complicated problem ... I think the best guide for you is when there's a complex problem remember you can break it down into well established bits where we do have some things that are very likely, competing explanations like Greenland is melting but exactly why, we don't know why, and speculative we really don't know what's the cloud feedback amount going to be and when people talk like that they're much more likely to be credible when they tell you that they have, you know, the smoking gun that proves or disproves, very rarely in complex science is that true." (emphasis added)
110514. RobertS at 05:16 AM on 10 September 2010
        How we know the sun isn't causing global warming
        "Bond et al. (1999) added further evidence that the timing of D-O events disqualifies them from being responsible for the current warming, by showing that the most recent D-O event may have contributed to the Little Ice Age (LIA):..." I'm not a huge fan of this paragraph. Bond 1999 actually concludes

        "Finally, if we are correct that the 1-2 kyr cycle is a persistent feature of climate, at least in the North Atlantic, then one conclusion seems inescapable. Independent of any anthropogenic forcing, the North Atlantic's climate eventually will shift (or in fact may be shifting now) toward the warm phase of the cycle"

        Suggestions: 1) Several recent papers have challenged the idea that D-O events are related to a underlying periodic forcing (published post Rahmstorf 2003); e.g. http://journals.ametsoc.org/doi/pdf/10.1175/JCLI3437.1 http://www.clim-past.net/3/129/2007/cp-3-129-2007.pdf 2) Even if a periodic component does exist (solar or otherwise), its magnitude must be so small as to render it nearly undetectable. Several authors (Rahmstorf, Alley, Ganopolski) argue for the use of stochastic resonance in modeling D-O events, whereby a very weak periodic forcing couples with strong noise to push the climate over a particular threshold in a glacial state. Something we have not observed to occur with much severity or regularity in the Holocene. -Robert S
110515. CBDunkerson at 05:09 AM on 10 September 2010
        Ocean acidification isn't serious
        Jim Prall #7, you think the hysterics over 'acidification' are bad? I just had a 'skeptic' (who was cited in the Cuccinelli vs Mann case) very determinedly telling me that the oceans are NOT becoming more acidic. Rather, they are becoming less alkaline. I suppose I should just be thankful that they have some grasp on reality... even if they refuse to allow words to hold their traditional meanings.
110516. CBW at 05:06 AM on 10 September 2010
        Pielke Sr and scientific equivocation: don't beat around the bush, Roger
        What we have: 1. Pielke claims that ARGO presents accurate instantaneous snapshot of OHC, despite ARGO saying it doesn’t:

        “Seasonal and interannual variability dominate the present 6-year globally-averaged time series. Sparse global sampling during 2004-2005 can lead to substantial differences in statistical analyses of ocean temperature and trend (or steric sea level and its trend, e.g. Leuliette and Miller, 2009).”

        and

        “Global coverage is essential, but for global change applications, Argo data must also have high accuracy and minimal systematic errors. Therefore, a high priority for Argo is to continue work aimed at identifying and correcting pressure measurement errors, especially those with systematic impacts.”

        2. Pielke denies that any substantial mixing with deeper ocean could have occurred during those 4 years despite evidence that 2000m trend differs from the 700m trend, and despite a very incomplete human understanding of total ocean circulation. 3. Pielke rejects other evidence, particularly sea level data, that OHC continued to increase unabated. All to support an assertion that something on the order of 5x10^21 Joules/year of average annual heating that prevailed since 1970 suddenly stopped in 2004 for no discernable reason. That conclusion is stretched far beyond the breaking point. I am struck by the concluding paragraphs of the Willis “eureka” article:

        “If there is a moral to this story, it’s that when it comes to understanding the climate system, it’s hard to imagine too much redundancy. Every scientist involved in these studies says the same thing: to understand and predict our climate and how it is going to change, we need it all. We need multiple, independent, overlapping sets of observations of climate processes from space and from the Earth’s surface so that we can create long-term climate records—and have confidence that they are accurate. We need theories about how the parts of the Earth system are related to each other so that we can make sense of observations. And we need models to help us see into the future. “Models are not perfect,” says Syd Levitus. “Data are not perfect. Theory isn’t perfect. We shouldn’t expect them to be. It’s the combination of models, data, and theory that lead to improvements in our science, in our understanding of phenomena.”

        Of course, when they say “[e]very scientist involved in these studies” they mean “every scientist except Roger Pielke Sr., who believes he can do it all with a single imperfect data set spanning four years.”
110517. John Hartz at 05:00 AM on 10 September 2010
        Pielke Sr and scientific equivocation: don't beat around the bush, Roger
        My apologies for the double post. I thought my initial post did not go through because of the URL I had embedded in it.
110518. KR at 04:59 AM on 10 September 2010
        The empirical evidence that humans are causing global warming
        T2000 - regarding your comments on these 10 points: 1) We know the amount of CO2 we're generating. The enhanced amount of CO2 in the atmosphere is found through direct measurements, and indicates that ~half the human generated CO2 amount remains in the atmosphere. That limits ocean exchanges. 2) Supporting point for 1, see comments for 1. 3) Known, measured increases in CO2, from 280 around 1850 to 380 now. 3) Supporting evidence related to 1, 2, etc., your comment on 'circumstantial' is incorrect. 5) The key is "at the precise wavelengths which CO2 absorbs", which your comment doesn't include. Decreased energy at CO2 wavelengths, along with increased energy elsewhere (from higher surface temperatures), is exactly what is expected with greenhouse heating. 6) Known and measured downward radiation, exactly as expected due to the physics involved, and with measured temperature increases from multiple data sets and independent instruments. 8) Actually, CO2 traps energy, meaning that stratospheric cooling is just what is expected - and measured. The mean CO2 radiation altitude is only 6km. 9) Warming troposphere means expanding troposphere, increasing tropopause height. It's a sign of warming no matter what the cause, but when tied to stratospheric cooling it's a fingerprint of greenhouse gas heating. 10) Your relevance in this comment? Ionospheric shrinkage is congruent with CO2 heating. All of these observed signs accompanying global warming are consistent with increased CO2 leading to an enhanced greenhouse effect. If you feel that some other cause is responsible for the warming trend over the last 150 years, in particular the last 35, then by all means I would love to hear your suggestion. However, you would need to supply both a different cause matching these fingerprints AND some reason why the CO2 enhanced greenhouse effect due to measured CO2 levels is NOT happening. So - two new things to believe in (one of which, CO2 not having an effect, is contrary to physics), versus one known change having predicted effects? I think I'll stay with the CO2 hypothesis...
110519. Yvan Dutil at 04:50 AM on 10 September 2010
        How we know the sun isn't causing global warming
        One point to mention. Some astrophysicist are trying very ahrd to understand the interaction between the Sun and the Earth climate. This is why they are asking for grant and are paid. In consequence, they have no reason to dismiss the importance of greenhouse gases. Nevertheless, their studies indicate that the sun impact, while be real is not the cause of the actual climate change. By the way, the sun-climate relationship as been studied astronomers way before the impact of greenhouse gases was understood. Herschel speculated in 1801 that when the sun was highly spotted, it “may lead us to expect copious emission of heat and therefore mild seasons,” while few spots suggested “spare emission of heat” accompanied by “severe seasons”. In order to test his speculation that the observed changes on the sun might affect climate, Herschel turned to records of the price of wheat in England as a proxy for climate, because meteorological measurements were lacking. Herschel imagined that costly wheat would result from “severe seasons,” while the “mild seasons” would moderate the price of wheat. Herschel found in records of wheat prices support for his speculation—five lengthy periods of few sunspots were tied to costly wheat.
110520. John Hartz at 04:47 AM on 10 September 2010
        Pielke Sr and scientific equivocation: don't beat around the bush, Roger
        Kudos to Dr. Pielke for posting on this comment thread. Both he and the author of the article should apologize to each other for being human and making disparaging remarks about each other. Unfortunately, the hard-core members of the Anti-AGW spin machine will never read this thread and will not benefit from it. Most of them belong to the "I've made up my mind, don't confuse with the facts" school of thought. To the anti-AGW crowd, this website is anathema and is an integral part of a "grand conspiracy." Some questions and a suggestion from a layman who wants to learn more about the topic of discussion, i.e., the measurement and distribution of the heat content of the oceans. 1. Where does the heat content of the upper layer of the Pacific go when an El Nino event dissipates? Does this heat transfer occur entirely within the boundaries of the upper layer being measured by the Argos buoys? 2. Where does the heat content come from when an El Nino event builds up? Does this heat transfer occur entirely within the boundaries of the upper layer being measured by the Argos buoys? 3. Is heat transfer the primary driver of the major ocean current systems? NOAA’s computation of the "Annual Global Oceanic Heat" has a considerable amount of statistical noise associated with it. Judging from the above exchanges, it seems there is a ongoing debate about the actual width of the statistical noise band. Perhaps the National Research Council should appoint a special committee to examine this issue.
110521. T2000 at 04:36 AM on 10 September 2010
        The empirical evidence that humans are causing global warming
        Re 1: There is little doubt about the contribution of anthropogenic CO2 emissions. But our understanding of the natural CO2 cycles is insufficient to estimate the size of its contribution. We don’t know, for instance, the size of CO2 outgassing from the deep sea into the atmosphere and the return flux (order of magnitude: 100 – 150 GtC/y). The statement as such bears no relevance to an expected enhanced greenhouse effect by CO2. It is only suggestive, circumstantial evidence. Re2: Agreed. It would be surprising if this CO2 was not present. But see comment under 1 and its conclusion: The statement as such bears no relevance to an expected enhanced greenhouse effect by CO2. It is only suggestive, circumstantial evidence. Re 3: Of course, fossil fuel burning will use oxygen from the atmosphere. But again: The statement as such bears no relevance to an expected enhanced greenhouse effect by CO2. It is only suggestive, circumstantial evidence. Re 4: This is to be expected as under 2. But again: The statement as such bears no relevance to an expected enhanced greenhouse effect by CO2. It is only suggestive, circumstantial evidence. Intermediate general conclusion: Wight’s reasoning is so far exclusively based on circumstantial evidence. Not a single proof is presented that CO2 can affect the natural greenhouse effect. But we have to take a closer look at his additional arguments. Re 5: This observation is incorrect. Satellite measurements have shown that more total radiation energy has been transported into space. Re 6: It is, of course, to be expected that with increasing CO2 in the atmosphere, more radiation from it contributes to downward radiation at its specific wavelength. But that is no proof that it contributes to additional warming because the authors who claim such an effect, are insufficiently aware of physical forces other than radiation, which remove heat from the atmosphere (e.g., evaporation and forced convection). Re 8. This has nothing to do with the greenhouse effect in the troposphere. CO2 is a gas that goes higher up in the atmosphere than water vapour. Consequently, it facilitates the radiation out into space. Re 9: The altitude of the tropopause differs depending on latitude. It is low at the poles and high at the equator. It is determined by the vertical convection. When it rises, it is a sign of warming at the surface – not that this warming is caused by CO2. Re 10: The underlying reference states: ‘The increase in global surface air temperature during the 20th century has been attributed mainly to the increasing atmospheric concentrations of greenhouse gases.’ It states that it is ‘attributed’ to greenhouse gasses of which water is the most important one – not that CO2 is the cause. Conclusion The AGW hypothesis is still exclusively based on the fact that CO2 is absorbing and emitting infrared radiation in a narrow band and the expectation that this will enhance the greenhouse effect. Point 5 is not correct. The outgoing radiation increased by 2.6 per cent or 6 W/m^2. Points 6 to 10 can be explained today without attributing an enhanced greenhouse effect to CO2. Written by Arthur Rörsch http://fp.dagelijksestandaard.nl/2010/09/eindelijk-empirisch-bewijs-voor-menselijke-broeikashypothese/#more-101195
110522. John Hartz at 04:29 AM on 10 September 2010
        Pielke Sr and scientific equivocation: don't beat around the bush, Roger
        Kudos to Dr. Pielke for posting on this comment thread. Both he and Graham should apologize to each other for being human and making disparaging remarks about each other. Unfortunately, the hard-core members of the Anti-AGW Spin Machine will never read this thread and will not benefit from it. Most of them belong to the "I've made up my mind, don't confuse with the facts" school of thought. To the anti-AGW crowd, this website is anathema and is an integral part of a "grand conspiracy." Some questions and a suggestion from a layman who wants to learn more about the topic of discussion, i.e., the measurement and distribution of the heat content of the oceans. 1. Where does the heat content of the upper layer of the Pacific go when an El Nino event dissipates? Does this heat transfer occur entirely within the boundaries of the upper layer being measured by the Argos buoys? 2. Where does the heat content come from when an El Nino event builds up? Does this heat transfer occur entirely within the boundaries of the upper layer being measured by the Argos buoys? NOAA’s computation of the "Annual Global Oceanic Heat" content as plotted on the graph posted at: http://www.nodc.noaa.gov/OC5/3M_HEAT_CONTENT/ has a considerable amount of statistical noise associated with it. Judging from the above exchanges, it seems there is a ongoing debate about the actual width of the statistical noise band. Perhaps the National Research Council should appoint a special committee to examine this issue.
110523. Jim Prall at 04:12 AM on 10 September 2010
        Ocean acidification isn't serious
        Also, lately I'm seeing frequent repetitions of the argument that ocean pH is still > 7 and so it is not "acidic", and that somehow precludes or invalidates use of the term 'Acidification' for lowering pH (even though this is perfectly valid and common scientific usage). Do we need to define this as a new "skeptic argument", or at least include a direct refutation of that move under this "it isn't serious" topic?
110524. Jim Prall at 04:09 AM on 10 September 2010
        Ocean acidification isn't serious
        I got to wondering if anyone had estimated the numeric relationship between atmospheric CO2 concentration change vs. ocean pH change. The dots in the graph you show suggest the glacial-interglacial difference of 100 ppm corresponded to a pH variation of 0.2 units of pH, so about 50 ppm / (0.1 pH) A bit of searching in Google Scholar yielded: K Caldeira, ME Wickett - Nature, 2003 "Anthropogenic carbon and Ocean pH", cited by 499 http://crecherche.ulb.ac.be/facs/sciences/biol/biol/CaldeiraWickett2003.pdf A key finding of theirs is that large but slow pCO2 changes led to somewhat smaller final ocean pH response, thanks to geologic-scale "buffering" effects (top 1/4 of their figure 1(b)). However, over shorter time spans, "[w]hen a CO2 change occurs over a short time interval (that is, less than about 104 yr), ocean pH is relatively sensitive to added CO2" So, just how sensitive, I wondered? I tried to glean from their graph whether ocean pH response to changes in pCO2(atm) is basically linear or logarithmic (they don't state either way). The X axis of figure 1(b) is log (or semi-log?) while the vertical bands for each pH level are spaced about equally, suggesting a logarithmic relationship. If so, the response for a doubling of CO2 along the bottom of fig. 1(b) (i.e. over short, human-scale time spans relevant to ACC) looks like roughly 0.3 pH units per doubling of pCO2. I'd appreciate if others would review the article and see if my takeoffs make sense of what's there.
110525. werecow at 03:50 AM on 10 September 2010
        A detailed look at climate sensitivity
        CBDunkerson: That makes sense. Thanks for clearing that up.
110526. CBDunkerson at 03:37 AM on 10 September 2010
        A detailed look at climate sensitivity
        Werecow, yes the values for 'climate sensitivity' that the article describes are all predicated on the assumption of the current climate. Whatever the 'true' value is would not hold exactly the same after multiple 'doublings' of CO2 over a span of thousands of years. You may notice that most of the paleoclimate studies which attempt to figure out climate sensitivity are focusing on time periods where conditions were relatively close to those we have today. If sensitivity were a constant it wouldn't really matter what time period you looked at. That said, the single largest climate sensitivity factor we have identified is water vapor... and that is tied directly to temperature over a very wide range. Basically, this largest aspect of climate sensitivity wouldn't show significant variation unless the temperature got to the point where all water froze or all water evaporated.
110527. Roger A Pielke Sr at 03:33 AM on 10 September 2010
        Pielke Sr and scientific equivocation: don't beat around the bush, Roger
        robhon - Thank you for your comments. With respect to changing metrics to diagnose global warming, if one elects, the global average surface temperature trend, of course, could be retained. However, we now have sufficiently robust analyses of the global annual average upper ocean heat content (since 2004 according to the experts, such as Josh Willis who work directly with this data) which permits us to adopt it as the primary global warming metric. This metric provides heat in its proper units - Joules, and the difference in heat content between time periods (i.e. the time slices) permits a diagnosis of the global annual average radiative imbalance in units of Watts per meter squared. Comparing the surface temperature trends and upper ocean heat content can itself be informative. In an earlier study Barnett, T.P., D.W. Pierce, and R. Schnur, 2001: Detection of anthropogenic climate change in the world's oceans. Science, 292, 270-274. http://pielkeclimatesci.files.wordpress.com/2010/04/barnett.pdf part of their conclusion reads "Perhaps the most important aspect of this work is that it establishes a strong constraint on the performance and veracity of anthropogenically forced climate models. For example, a climate model that reproduces the observed change in global air temperature over the last 50 years, but fails to quantitatively reproduce the observed changed in ocean heat content, cannot be correct." This was written in 2001 and applies even more so today since the upper ocean heat data is more accurate.
110528. MattJ at 03:31 AM on 10 September 2010
        The Little Ice Age: Skeptics skating on thin ice
        This "basic version" is pretty good; I really love the title. But again, as I have said so often, a "basic version" has to avoid the fancy vocabulary that repels the target audience: 'thermohaline' and 'forcing'. It is especially bad that 'forcing' is used with no preparation for the technical sense of the word, which is SO different from the sense the reader is likely to assume -- if he assumes any meaning for the word at all. Also, I would have put much more emphasis, using bold fonts and the like, on "But since WW2 the sun has slowly grown quieter, yet the temperature on Earth has gone up." Such emphasis goes a long way to prepare the reader for the conclusion that the skeptics argument is completely groundless. That, by the way, is what the article should be saying instead of pathetically weak conclusion like, "the skeptical argument... is unlikely". We can say a lot more about it than just 'unlikely'. The skeptical argument is wrong, very wrong. We should say so in no uncertain terms.
        Moderator Response: [Graham] Sorry, but this is the statement that's wrong: "We can say a lot more about it than just 'unlikely'. The skeptical argument is wrong, very wrong". That may be your opinion, but there is no scientific evidence to support it. If there was I'd be more than happy to use it, but in this instance we really must be candid, and admit the uncertainty that pervades this whole issue. Fact is, if the cause and effects of the LIA and MWP were not so equivocal and our knowledge so sketchy, the skeptics wouldn't keep bringing it up. The argument is weak, but so is any rebuttal that relies solely on scientific evidence.
110529. Daniel Bailey at 03:27 AM on 10 September 2010
        The Little Ice Age: Skeptics skating on thin ice
        Re: Cornelius Breadbasket (4) Many factors are in play regarding temperature balance, with solar activity being just one. If solar activity ramps up and other forcings and feedbacks stay uniform, then yours would be a reasonable assumption. So, yes, you would be correct in that event. But remember that solar forcing, compared to other forcings, is not the main actor on this stage. CO2 is the big dog. If, at the same time, man reduces the quantities of sulfate aerosols injected into the atmosphere (which act to reduce the GHG warming coming from the CO2, then temperatures could rises even more. Factoring in albedo changes in the Northern Hemisphere if, as expected, the Arctic sea ice melts out in the next few years, then expected changes could get very "pronounced". All of these converging together = bad news. Worst case scenario: If on top of all this a methane hydrate/clathrate release initiates... ...then the Earth pinball game goes TILT. What is certain: many uncertainties exist. And we're all in this together. The Yooper
110530. muoncounter at 03:18 AM on 10 September 2010
        How we know the sun isn't causing global warming
        "solar magnetic field has not changed appreciably over the past three decades" By way of a partial update, see Solar wind loses power, which notes that "the sun's underlying magnetic field has weakened by more than 30% since the mid-1990s". The weaker solar (and hence interplanetary) magnetic field should mean higher incidence of galactic cosmic rays (GCRs) -- which matches observation. GCRs are the high-energy particles that should seed clouds and thereby cool the earth in the Svensmark model. However, we have persistent warming during this period. So weaker magnetic field = more GCRs and warming is indeed 'a nail in the coffin' for this idea.
110531. tobyjoyce at 03:12 AM on 10 September 2010
        The Little Ice Age: Skeptics skating on thin ice
        A feature of the Little Ice Age were Frost Fairs on London's Thames, when it froze in the winter. I have heard claims that these were annual occurrances, but they were not, but were quite infrequent and were often of short duration. The last one was held in 1814, and lasted 4 days. Frost Fairs
110532. Rob Honeycutt at 02:54 AM on 10 September 2010
        Pielke Sr and scientific equivocation: don't beat around the bush, Roger
        I've been reading this whole exchange with great excitement. It's rather like having a box seat at the big game. We should all thank Dr Pielke for taking the time to post his responses here. Something disturbs me about this notion that Dr Pielke seems to be putting forth that OHC should supplant global temperature readings as a proxy for global warming. Please correct me if I have that wrong. When he says "global warming has halted" based on OHC measurements I read a rhetorical leap that may not yet be justified. I believe I understand that OHC should be a better metric being that such a larger volume of the actual energy is resident in the ocean. But it's also strikes me as an act of changing the rules of the game at half time. It's almost even like saying, "Well, we've been playing football the first half, but really baseball is a much better game so let's play that the second half." The part that makes me suspicious of this attempt to change the game is that, while baseball might be the better game, it sounds like we're still figuring out how to build baseball mitts and bats, and measuring how far apart the bases should be. The uniforms aren't yet even stitched up and we're making grand statements about the score? Is the ARGO buoy network really robust enough to completely change how we define climate change? Think back 20 years ago. Where were we with satellite readings? We had big battles going over the UAH reporting cooling while ground stations were reporting warming. Right? There were a lot of kinks to work out to get to the understanding of atmospheric temperature we have today. I don't want to jump to conclusions about any ulterior motives that Dr. Pielke might have in this. I accept that he is an upstanding scientist, just as the others opposing him here are also upstanding scientists. Each scientist is still human and has personal motivations. From my box seat I would suggest it's a mistake to make the rhetorical leap in referring to OHC as "global warming." If baseball truly is the better game, get all the gear and all the rules right first, then change the game. In the mean time, be careful with your words. The stands are full of very rowdy fans.
110533. Cornelius Breadbasket at 02:38 AM on 10 September 2010
        The Little Ice Age: Skeptics skating on thin ice
        What is really worrying is that solar activity has been so quiet since 1950, yet temps are still increasing. This implies that once solar activity starts up again, global warming will speed up - is this right?
110534. Tom Dayton at 02:26 AM on 10 September 2010
        Pielke Sr and scientific equivocation: don't beat around the bush, Roger
        RSVP, the mechanisms by which the atmosphere heats the ocean certainly are known. For example, a Google search for "heat transfer from atmosphere to ocean" returns a Columbia University class lecture page, which explains that conduction and radiation do that. Regarding radiation:

        "The infrared radiation emitted from the ocean is quickly absorbed and re-emitted by water vapor and carbon dioxide and other greenhouse gases residing in the lower atmosphere. Much of the radiation from the atmospheric gases, also in the infrared range, is transmitted back to the ocean, reducing the net long wave radiation heat loss of the ocean. The warmer the ocean the warmer and more humid is the air, increasing its greenhouse abilities. Thus it is very difficult for the ocean to transmit heat by long wave radiation into the atmosphere; the greenhouse gases just kick it back, notably water vapor whose concentration is proportional to the air temperature."

110535. Lars Karlsson at 02:17 AM on 10 September 2010
        A detailed look at climate sensitivity
        Figure 1 displays temperatures for two Antarctic sites. I think it might confuse readers that they are called "global" in the caption.
110536. werecow at 02:16 AM on 10 September 2010
        A detailed look at climate sensitivity
        Also the link to Knutti & Hegerl 2008 is broken (there'a %20 tagged on at the end).
110537. Daniel Bailey at 02:13 AM on 10 September 2010
        The Little Ice Age: Skeptics skating on thin ice
        Re: doug_bostrom (2)

        "Nobody on the Internet would be wrong, if we were all bachelors."

        If we were all bachelors we wouldn't be on the Internet. Catch-22. Nice post Graham! You may want to reiterate that, while the LIA was an intensely "personal" event to those in Northern Europe, there is a lack of evidence to extend its effects to the rest of the globe (thus no "global cooling" during the LIA). The Yooper
        Moderator Response: [Graham] Thing is Dan, when we lack evidence - and this applies to the MWP as well as the LIA - introducing the global argument serves to muddy the waters, and may be construed as over-egging the issue. A lack of evidence is not grounds for suggesting further problems with the skeptical argument in my opinion.
110538. JMurphy at 02:11 AM on 10 September 2010
        Pielke Sr and scientific equivocation: don't beat around the bush, Roger
        NETDR wrote : "A 5 year pause cannot happen if Catastrophic AGW is real." It would depend on what 'Catastrophic AGW' is. What does that mean ?
110539. werecow at 02:07 AM on 10 September 2010
        A detailed look at climate sensitivity
        I've been wondering about this for a while, but doesn't climate sensitivity depend on your initial conditions to some degree? For example, if you start of with a positive forcing under glacial conditions, you need to take into account ice albedo feedback. On the other hand, if you start of in hothouse conditions where no significant ice caps exist, it seems that the same forcing would not be amplified in the same way. Am I missing something, or is it just that we focus on sensitivity under conditions comparable to those of today?
110540. Doug Bostrom at 02:04 AM on 10 September 2010
        The Little Ice Age: Skeptics skating on thin ice
        Chris: And my wife has soundly taken me to task for hanging round the blogosphere at 1.30 am when I'm meant to be finishing a psych report :-) Nobody on the Internet would be wrong, if we were all bachelors. :-)
110541. Albatross at 01:56 AM on 10 September 2010
        Pielke Sr and scientific equivocation: don't beat around the bush, Roger
        All, My last post on this. I would encourage everyone concerned to read the summary on global OHC by Palmer et. al (pages 60-61)in the "2009 state of the climate report"
110542. dana1981 at 01:55 AM on 10 September 2010
        How we know the sun isn't causing global warming
        Ned @ 19 summed it up well. Yes, there are nuanced solar influences which can impact local temperature and weather, but the Sun is not responsible for the long-term increase in the average global temperature. It's important to distinguish between not understanding all solar effects and understanding the big solar effects. As for the format of the article, there's a reason I linked to the Intermediate version at the beginning. It has a very thorough list of peer-reviewed studies on the subject, and in fact that's primarily what it's devoted to. Thus it doesn't make sense to also devote the Advanced version to a long list of peer-review references. Instead I thought it would be a worthwhile endeavor to go through how the solar radiative forcing is calculated so that people can see the numbers for themselves. It's all well and good to read the IPCC's range of possible solar forcing values, but personally, I like to go through the calculations myself. And I think that's appropriate for an 'Advanced' rebuttal.
110543. chris1204 at 01:52 AM on 10 September 2010
        How we know the sun isn't causing global warming
        Thanks for clearing up an urban myth Ned (that's the crisis and opportunity one). As an interesting aside, there's a similar confusion around the Greek word 'stasis' which today we use to mean 'coming to a halt' but to the ancient Greeks meant a political crisis (no - I'm not showing off my non-existent erudition in classical Greek - my 21 year old son is the seriously bright Greek scholar who is now dipping into Mandarin!). Plate tectonics is fascinating. In Darwin's 'Voyage of the Beagle,' there's a fascinating description of major earthquake in South America - Darwin speaks of a big chunk of land rising. Darwin can't explain it but notes the phenomenon. I recall reading his description and having a huge 'Aha' moment - Darwin had just observed a shift which to a modern observer is all too obviously plate tectonics at work. So actually, the evidence for plate tectonics today is a little bit more than circumstantial. Indeed, we can measure its operation. Darwin's by contrast explained the phenomenon he observed in terms of volcanism (if my memory serves me correctly) citing the apparently near simultaneous eruption of a volcano some many (but not too many) miles away. In fact, of course, we recognise today that volcanic activity has heaps to do with plate tectonics. So Darwin proved was working on a good hunch - he just didn't know how to integrate the information because he didn't have all the bits of the jigsaw. I definitely don't reject evidence just because it's circumstantial - I merely argue for greater caution as would any defence barrister. But I don't hold a 'brief' for 'scepticism' even if my mind tends that way.
110544. NETDR at 01:45 AM on 10 September 2010
        Pielke Sr and scientific equivocation: don't beat around the bush, Roger
        Re Daniel Bailey [59] As I stated earlier Did anyone post that the Atmosphere was cooling at the same time that the oceans were cooling according to both the GISS and UAH satellite temperature readings. http://www.woodfortrees.org/plot/uah/from:2005/to:2009/plot/uah/from:2005/to:2009/trend So the heat isn't in the oceans and it isn't in the atmosphere, where did it go ? To the Lithosphere ? I doubt it. ****** The charge of cherry picking is inadequate because if the measurements are correct, which is an issue which has been addressed elsewhere heat cannot leave the system for a 5 year period. It could go between the atmosphere and the oceans and back again due to El Nino's and La Nina's but it must keep increasing. A 5 year pause cannot happen if Catastrophic AGW is real. When huge positive feedback is shown not to be happening currently the defense is that the heat is being stored in the oceans to come back and cause rapid warming later. If it hasn't been stored during a 5 year period the rapid warming probably won't happen. No cherries involved if the data is correct.
110545. chris1204 at 01:29 AM on 10 September 2010
        The Little Ice Age: Skeptics skating on thin ice
        This is a fascinating follow up from dana1981's post. The C14 data cited show a solar activity level just around 1950 that is greater than that of the putative mediaeval warm period. If we go back to dana's post, we find a graph taken from Lockwood (2001) which shows maximum coronal source flux in the mid 1990s 1.5 times greater than the 1750 maximum. Lockwood's paper is rich in data - the abstract says coronal source magnetic flux had risen 34% since 1963 and 140% since 1900. If I understand her correctly, flux is a good measure of TSI. Her 10Be isotope data which she says is also a good proxy for flux suggest peaks in 1500 with a trough around 1520 and a huge trough in 1700. 10Be peaks dramatically around 1950 as best as I can make out from her graphics. I'm not quite sure how her data translate into the current decade with its 'quiet' sun. Alas, I haven't yet mastered (and probably never will) the art of posting links and graphics but then I always was a technological dinosaur :-( But I would be interested if anyone wanted to have a closer look and see how these data play out in the overall picture. And my wife has soundly taken me to task for hanging round the blogosphere at 1.30 am when I'm meant to be finishing a psych report :-)
110546. Tom Dayton at 01:18 AM on 10 September 2010
        Pielke Sr and scientific equivocation: don't beat around the bush, Roger
        Excellent rephrasing, MrJon!
110547. Albatross at 01:13 AM on 10 September 2010
        Pielke Sr and scientific equivocation: don't beat around the bush, Roger
        GPWayne @77, Well stated. I was going to address comments made by HR directed at me, but what is the point? They and Pielke have made up their mind, you and I and others have made up ours based on the data and caveats associated with such data, and thought son this matter by experts working closely with the data (Lyman, Tremberth, von Shuckmann, Levitus, Willis etc.) It would have been nice to say at the end of this exchange that Pielke Snr recognized and acknowledged what he said on OHC (and other climate metrics) was misleading and perhaps even revised his public statement/s on those issues. But sadly other, less scientific, factors seem to be standing in his way. All I will say to HR regarding his/her comment: "Really, enough of the morality tales! Stick to the science." First, those two points are not mutually exclusive. Second, maybe your second sentence should be directed at Pielke Snr and not me and others here (and elsewhere) who have (with very good scientific reason) criticized Pielke.
110548. Ned at 01:02 AM on 10 September 2010
        How we know the sun isn't causing global warming
        It's said that the Chinese use the same character to represent 'crisis' and 'opportunity.' And apparently, one Chinese curse goes, 'May you live in interesting times!' The "crisis" and "opportunity" thing is a bit of a misunderstanding, at least as most Westerners use it. The words for "crisis" (wēijī) and "opportunity" (jīhuì) both incorporate the character "jī" but it doesn't really convey any sense of connection between the two. "Jī" is combined with lots of other characters to make bisyllabic words with all kinds of different meanings. Bringing this back within hailing distance of the topic of this site, Al Gore unfortunately repeated this fable about "crisis/opportunity" on a couple of occasions in speeches about climate change. For example, from his 2007 speech accepting the Nobel Prize:

        In the Kanji characters used in both Chinese and Japanese, "crisis" is written with two symbols, the first meaning "danger," the second "opportunity."

        So, chriscanaris, you've got good company on that one!
110549. Ned at 00:44 AM on 10 September 2010
        How we know the sun isn't causing global warming
        chriscanaris: I know I make this comparison a lot, but climate change is very similar to plate tectonics in a lot of ways, one being the importance of "multiple converging lines of evidence." Both theories seek to explain very slow planetary-scale processes that can't be completely replicated in the lab and that aren't amenable to the traditional controlled-experiment that people in certain other fields get to use (there's only one Earth!). Thus, both theories rely on modeling, observational studies ... and multiple converging lines of evidence. We all accept plate tectonics (I hope), but some are reluctant to accept anthropogenic climate change. Of course, it's possible that in this case the particular lines of evidence for climate change are individually or collectively not as impressive as those for plate tectonics. Alternatively, one could speculate about other reasons that would explain people's willingness to accept one theory while rejecting the other, but I'd prefer not to wander that far off-topic. My point is just that we don't generally object to the reliance on "multiple lines of evidence" in principle, when it comes to complicated theories about planetary-scale physical processes.
110550. Eric (skeptic) at 00:34 AM on 10 September 2010
        A detailed look at climate sensitivity
        Daniel Bailey (#25) said "in order for the air to hold increased moisture over time it must have warmed." True for an ideal situation (the C-C relationship), but certainly does not hold for a global average. If that global average increased moisture is evenly distributed then the world must be warmer on average. If not, then not necessarily depending on how uneven water vapor is (as a whole, not just the increase). This is an very common misconception here, and your second point is a good starting point: "Water vapor acts as a feedback to the warming". How? By absorbing and emitting IR, some of which returns downward. The distribution of water vapor is what determines the amount of GH warming from WV. There is more GH warming from WV on average if WV increases on average. But that is only true if the distribution of that WV stays the same (meaning weather stays the same on average). There are many threads here insisting that weather is changing and that the distribution of WV is more highly concentrated (increased precipitation extremes as one common example). When WV is highly concentrated, the areas with greater concentration reach saturation for IR absorption. The areas with less have less absorption than if the WV were more evenly distributed. The result is less warming (sensitivity) than if the weather remained constant with the increased warming from CO2.

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