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Comments 124201 to 124250:

124201. Ned at 14:27 PM on 13 February 2010
        Is CO2 a pollutant?
        RSVP writes: "In a way Riccardo, you are right. This is a bad comparison because it tends to show AGW is not related primarily to "anthropogenic" CO2, ..." We've been round and round this before. Elsewhere on this site there are multiple cogent explanations of the evidence that CO2 is the primary (but not sole) driver of anthropogenic climate change. It gets a bit tedious to have to keep answering the same spurious objections over and over again. See these links to other posts on this site: (1) http://www.skepticalscience.com/How-do-we-know-CO2-is-causing-warming.html (2) http://www.skepticalscience.com/empirical-evidence-for-global-warming.htm (3) http://www.skepticalscience.com/CO2-is-not-the-only-driver-of-climate.html The Martian climate differs from that of Earth in a number of respects, none of which contradicts the physics of greenhouse gases in the terrestrial atmosphere.
124202. Ned at 14:17 PM on 13 February 2010
        Is CO2 a pollutant?
        Jenik Hollan writes: "Maybe, no GCMs for Mars exist yet. So we don't know how many kelvins it is for Mars. Science may not need it, but education does." Actually, NASA-Ames has a Mars GCM. RealClimate has discussed the climates of Mars and Venus, though neither post is very satisfactory IMHO. When I was in graduate school we did a Earth/Mars/Venus comparison in one of my global climate courses, and it would seem like a natural topic for a post.
124203. RSVP at 13:26 PM on 13 February 2010
        Is CO2 a pollutant?
        Riccardo "There's no possible comparison between the earth and Mars " I just made one, precisely because using this example isolates factors such as the effect of water vapor. Mars is perfect laboratory for testing greenhouse theories, and yet, in reading replies of MattJ, jenikhollan for instance, one encounters resistance in the form of ...not enough atmospheric pressure, you need help from water vapor, Mars has a different albedo, dust storms....etc. In a way Riccardo, you are right. This is a bad comparison because it tends to show AGW is not related primarily to "anthropogenic" CO2, especially when you continue looking closer at this particular example, as CO2 on the Earth is thousands of times more diffuse, which means IR surface emissions have even less chances of being affected by it.
124204. Steve L at 12:45 PM on 13 February 2010
        Skeptical Science housekeeping: iPhone app, comments and translations
        Thanks for directing me to the html code for posting active links. I wouldn't have bothered to learn that if you didn't point the way.
124205. 40 Shades of Green at 12:00 PM on 13 February 2010
        There's no empirical evidence
        Thanks for a wonderful site. I do however have to take issue as I believe you are posting a strawman. The issue is not whether or not manmade CO2 is causing warming. It is whether or not it is going to cause catastrophic warming. No serious skeptic disputes observations 1 and 2. IE, manmade CO2 is indeed increasing and that increasing CO2, absent either positive or negative feedbacks, will increase the temperature of the earth. The consensus on all sides is that a doubling of CO2, absent feedbacks, will increase the earth’s temperature by one degree. The models assume substantial positive feedbacks and per the IPCC, predict 2 to 6 degrees of warming per doubling of CO2. We are told that the reason we should believe the models ability to predict the future, is because of their ability to predict (model) the past. IE, we should believe the forecast, because the hindcast is accurate. Up until recently, I was prepared to accept the models hindcasting abilities. Until I read extracts from the leaked Harry.Readme.txt file. For any of your readers who do not know. Harry was the University of East Anglia programmer who tried to make sense of the HADCRUT code. Here is my favourite extract. "Here, the expected 1990-2003 period is MISSING - so the correlations aren't so hot! Yet the WMO codes and station names /locations are identical (or close). What the hell is supposed to happen here? Oh yeah - there is no 'supposed', I can make it up. So I have :-) " Now if ever there was a clear case for an engineering audit, not to mention a public inquiry, this is it. See this link for more examples of the code. http://wattsupwiththat.com/2009/11/25/climategate-hide-the-decline-codified/ But let us put that aside and assume that the hindcast is correct. So the question then is how well have observations matched the forecast. Well to start with, I being skeptical, and having read the Harry.Readme.Txt file and looked at www.surfacestations.org, will not trust the surface measurements. That leaves me with the satellite measurements, UAH and RSS, and the ocean heat content measurements, as measured by the Argos buoys. The satellites give us 30 years of data and Argos buoys just 7. So what do they show. Well UAH shows that there has been no statistically significant warming for 15 years. See http://noconsensus.wordpress.com/2009/11/12/no-warming-for-fifteen-years/. (This data can be downloaded and you can plot it yourself to verify it) RSS’s no statistically significant warming period is slightly shorter. For some reason 30 years is talked about as being the timeframe required to measure climate, so no statistically significant warming in half a climate timeframe, strikes me as important. What needs to be also pointed out in a discussion on the Satellite temperature record is that three major volcanos, two of them tropical, occurred during the first half of it. Mt St Helens, El Chichon and Pinatubo. These lowered the global temperature during the first half of the record. (Tropical volcanos have a higer impact on temperatures) This is best illustrated in a graph created by Bob Tisdale here http://i44.tinypic.com/3442jo9.jpg. What he shows is that the 1982 / 1983 El Nino was almost as powerful as the 1998 El Nino that made 1998 the hottest year in recorded history. However temperatures were masked by the effects of El Chichon. What is interesting is that, even with the volcanoes skewing the earlier part of the record, global temperatures only rose by 1.3 to 1.7 degrees per century depending on which satellite record you want to choose (and by slightly more if you are happy to use the surface records.) Having said that, Global Warming theory states that the lower troposphere, where the satellites do the measuring, should warm faster than the surface, (by about 20% per John Christy) so a 1.3 degree per century rise in the Lower Troposphere is equivalent to 1.1 at the surface. And now to get to Ocean Heat Content. I do not trust any measurement before the Argos buoys were deployed in 2003. Since then ocean heat content has remained flat See http://bobtisdale.blogspot.com/2010/01/nodc-ocean-heat-content-0-700-meters.html . It should be pointed out too that the thermal mass of water is a lot greater than that of air, so the variability of Ocean Heat Content is less. Therefore conclusions can be drawn from much shorter periods of Ocean Heat Content than Surface Temperatures. We have 7 years which is a quarter of a climate timeframe, and so far, no warming. So to summarise. I will believe it when 1) An engineering audit is done on the surface temperature records and they are revised or confiremed. 2) The models continue to accurately hindcast and 3) 15 years of satellite measured temperatures match the model predictions, or 8 years of Ocean Heat Content measurements match the model predictions. Or they find the missing tropical hotspot fingerprint of manmade catastrophic global warming, but that is another days discussion.
        Response: "No serious skeptic disputes observations 1 and 2. IE, manmade CO2 is indeed increasing and that increasing CO2, absent either positive or negative feedbacks, will increase the temperature of the earth"
        
        I wish that were true. I list a selection of skeptic articles arguing that human contribution to atmospheric CO2 is tiny and that increasing CO2 doesn't cause much warming. Ian Plimer who I'm sure considers himself a serious skeptic argues both points in his book Heaven and Earth.
        
        You do make a good point though. I thought ending this article with 'the planet is accumulating heat' was sufficient to show humans are causing global warming. However, I think an extra step is now required, something to the effect of 'extra heat causes surface warming' (I'll work on a less clumsily worded version). In other words, that our climate is sensitive to radiative forcings. I would base this not on models but on the many papers looking at empirical data of temperature change versus forcings to calculate climate sensitivity.
        
        Re ocean heat, note that the Bob Tisdale webpage you link to looks at upper ocean heat from 0 to 700 metres deep. Upper ocean heat shows more variability than ocean heat calculated to greater depths as the upper ocean exchanges heat with deeper waters. Ocean heat content calculated to 2000 metres deep finds less variability and that oceans are still accumulating heat  (von Schuckmann 2009). Note - this analysis is based solely on Argo data, hence the 2003 to 2008 time frame:
        
        
124206. Tony O at 11:49 AM on 13 February 2010
        Skeptical Science housekeeping: iPhone app, comments and translations
        The recent comment on my profile is not mine. I am not in the pro pollution camp, I am much more in the beyond alarmist maybe even the doomsayer camp. I am not a scientist and acknowledge I might be wrong, in fact I hope I am wrong. Your house your rules. However, I see getting rid of the bile as a good thing. I don't recall that you have ever deleted a comment of mine, but they are often ignored. An observation not a complaint, you do have a day job. I regularly read your posts and find them very informative.
124207. Riccardo at 11:38 AM on 13 February 2010
        Is CO2 a pollutant?
        Mars is also very dry and subject to intense dust storms which have a cooling effect. There's no possible comparison between the earth and Mars just because there some CO2 in both atmospheres.
124208. jenikhollan at 09:53 AM on 13 February 2010
        Is CO2 a pollutant?
        On Mars: there is some greenhouse, but just a faint one, several kelvins only. This is due to CO2 being the only gas there, even if a bit more abundant (I mean mass per column) than on the Earth. And, due to the very low air pressure, so that spectral lines remain very narrow, lacking the so-called pressure (or collisional) broadening. Low pressure and almost no water vapour give but a faint greenhouse effect. Albedo has nothing to do with that effect, nor sunshine: the effect is the difference from such temperatures, which would result from the existing albedo and sunshine in the absence of GHGs. Still, it is amazing there is no paper which would evaluate the 'deltaT' due to CO2 for Mars... just some old, outdated crude estimates. Maybe, no GCMs for Mars exist yet. So we don't know how many kelvins it is for Mars. Science may not need it, but education does. jenik hollan, http://amper.ped.muni.cz/light
124209. MattJ at 08:59 AM on 13 February 2010
        Is CO2 a pollutant?
        RSVP writes: ...And yes, I am aware that Mars only gets about half the sunshine as the Earth, however, shouldnt all that CO2 be keeping the planet a little warmer? The short answer to your question is: No. There are too many other variables contributing to the "greenhouse effect" such as planetary albedo, which is very different in the case of Mars and Earth. Besides: -40C IS a lot warmer than the cold of space. So the greenhouse effect IS keeping Mars warmer than it would otherwise be. Just not by so much.
124210. MattJ at 08:54 AM on 13 February 2010
        Is CO2 a pollutant?
        Westwell writes: "Oceans don't acidify because of CO2 absorbed from the atmosphere". I have heard 'skeptics' make this claim before. The only argument they can make to support this claim is poor memories of high school chemistry coupled with unshakeable faith in the absolute power of buffers. Yes, of course it is 'buffered'. But even buffers can be overwhelmed. Did it ever occur to Westwell that this might be exactly what is happening? Nor is a large change in pH necessary to explain the current problem known as "ocean acidification". Even a very small change is enough to interfere with shell formation -- especially when the small pH change is accompanies by a large change in carbonate ion concentration. A detailed explanation of why Westwell is wrong is hard to find on the open Internet, but when the Royal Society says we already have a 0.1 reduction in pH due to atmospheric CO2, it takes more than the word of a biased skeptic to overturn their scientific authority.
124211. MattJ at 08:44 AM on 13 February 2010
        Is CO2 a pollutant?
        The article makes a lot of good points, but it still sounds like quite a 'stretch' to classify CO2 as a 'pollutant'. However, given the political climate, and the pressing need to regulate CO2 emissions (and other GHGS), it is a 'stretch' we should be willing to live with; the alternative is much worse.
124212. jenikhollan at 05:53 AM on 13 February 2010
        Is CO2 a pollutant?
        In my lectures on light pollution I say that light (man-made, at night) and CO2 are similar pollutants: both have been considered as harmless 30 years ago, both are very harming. The main cure for both is a large reduction of energy use. Needing to define such pollution properly, I wrote a text 'What is light pollution, and how do we quantify it?': http://amper.ped.muni.cz/light/lp_what_is.pdf It discusses the concept of pollution thoroughly, ending with a note on pollutants, commenting on religious connotations etc. Pollution in a modern sense should be not taken emotionally, being a rather scientific term. I touch the history of the concept at p. 2 of my paper. The very beginning of the paper reads: 'Generally, pollution is an impairment of the purity of the environment. As a pure,reference state of the environment, its natural state is to be considered, if applicable and adequate.' I owe that scientific, non-emotional approach to terminology, which is so useful if not indispensable to understand the problem properly, to Pierantonio Cinzano, see the hyperlink in the paper. I admit that it took me a year or more to identify myself with it. A good friend of mine, a topmost expert in LP, did not accept such attitude... I hope my text might help you in studying the issue and decide for yourself. Jenik Hollan, http://amper.ped.muni.cz/gw
124213. angliss at 04:17 AM on 13 February 2010
        Is CO2 a pollutant?
        One of the problems with geoengineering is one of logic. In order to accurately counteract the effects of anthropogenic CO2 on the global climate and biosphere, you need accurate models of what the effects are going to be, where's going to be hit the worst, where you get the most bang for your metaphorical buck. In other words, you need models that can project effects, the very thing that most AGW skeptics (and most geoengineering proponents) say we don't have at present. So if the current models aren't good enough to accurately project a problem, then they're not good enough to accurately project a solution either. And if they're good enough to project the problem, then they're good enough to accurately project a solution. And in fact, the "best" solution projected thus far is not geoengineering, but rather retooling human energy consumption to not be carbon-based.
124214. carrot eater at 02:54 AM on 13 February 2010
        Is CO2 a pollutant?
        suibhne: Those are extremely simplified cartoon illustrations, to help show people the basic concepts of the energy balance without having to write thousands of equations. Most people aren't interested in seeing the actual line-by-line radiation transfer codes, which indeed carry all the wavelength-dependent detail you are worried about, or the variation with altitude (a single-slab atmosphere is not sufficient for serious calculations). If you want to get into those details yourself, you can start with this interface with the MODTRAN model. http://geoflop.uchicago.edu/forecast/docs/Projects/modtran.orig.html You can see that the quantised nature of absorption and emission are very much considered. Note that this isn't a climate model, but just radiation code. In it, you fix the Earth's surface temperature and the composition of the atmosphere, and the code then figures out how radiation propagates around.
124215. suibhne at 02:27 AM on 13 February 2010
        Is CO2 a pollutant?
        carrot eater .................It doesn't, really. That's why detailed radiation transfer calculations are necessary, explicitly considering the full spectrum of wavelengths, and therefore those spectral lines. Planck's Law gives the maximum possible radiation at any given wavelength; S-B integrates that over all wavelengths. To deal with something with quantised bands in the context of Planck's Law, you'd have to introduce a wavelength-dependent emissivity...... I agree, but then why do advocates of AGW theory frequently cite an atmosphere radiating back to the Earths surface using the Stephan Boltzman equation to justify their calculations?
124216. joseph449008 at 01:50 AM on 13 February 2010
        Working out future sea level rise from the past
        The thermal expansion of water is also non-linear. It accelerates with increasing temperature over 4C. It looks pretty complicated to solve. It's also very slow. Sea level lags temperatures by thousands of years.
124217. Ned at 01:30 AM on 13 February 2010
        Is CO2 a pollutant?
        BP writes: If all else fails, we can put some limestone into oceans to balance CO2. There are several million gigatons of it in crust, a tiny little percentage would suffice. CO2 in the oceans and atmosphere will be out of equilibrium for a long time to come. By your suggestion we would need to start a long-term program of continuously manipulating the chemistry of the world's oceans. I guess that could be run by the same international agency that is responsible for continuously injecting aerosols into the stratosphere to increase the planetary albedo, right? This is ridiculous. We have two choices: (1) Burn lots of fossil carbon now, postponing the inevitable switch to nuclear and renewable energy for a few decades, and leaving future generations the burden of dealing with our mess (radiative forcing of climate, ocean acidification) for millennia to come; or (2) Start transitioning to a low-carbon energy economy now, thus creating less of a mess for future generations to have to clean up. It seems to me that advocating (1) is the height of selfishness. The other, ironic point here, is that BP and others ought to think seriously about the implications of their glib suggestion that we can geoengineer our way out of the climate and ocean-chemistry impacts of our wasteful fossil fuel consumption. In my experience many so-called "skeptics" make a big deal about the dangers of letting a big, impersonal agency control our lives via cap-and-trade systems, carbon taxes, or whatever. But planetary geoengineering would require an international entity with the power to "adjust" the climate by whatever actions it sees fit, and with the power to impose taxes to pay for its activities. So "skeptics" are essentially rejecting a market-based solution (reducing CO2 emissions by cap-and-trade or carbon taxes, thus letting the market itself develop more efficient ways of generating power) in favor of a command-and-control solution (geoengineering). Once we start injecting sulfate into the stratosphere and grinding up carbonate rocks to dump into the ocean, we need to keep doing that effectively forever. Who's going to take responsibility for that? And who's going to decide how much aerosols to put in the stratosphere, and thus what the global temperature should be? I imagine that India and Canada might disagree about that. Are we going to take a vote?
124218. carrot eater at 01:04 AM on 13 February 2010
        Is CO2 a pollutant?
        Actually, carbon is labeled in a way, as 12C, 13C or 14C, and that enables some interesting calculations for tracking carbon as it comes into and goes around the cycle. But that isn't really relevant to the point.
124219. carrot eater at 01:00 AM on 13 February 2010
        Is CO2 a pollutant?
        thingadonta: Your premise is actually wrong. The EPA can't regulate CO2 emissions unless they are found to be covered under the language of the Clean Air Act. Perhaps that has some philosophical consequence for you, but it's really just a legal question. Berenyi: Carbon atoms aren't labeled, but you know if any given activity is re-circulating carbon, or introducing new carbon. Breathing is recirculating carbon that was already in the climate system, so it's irrelevant to the discussion. Digging up and burning coal is adding carbon that had been removed from the climate system. This is a very simple concept. suibhne: It doesn't, really. That's why detailed radiation transfer calculations are necessary, explicitly considering the full spectrum of wavelengths, and therefore those spectral lines. Planck's Law gives the maximum possible radiation at any given wavelength; S-B integrates that over all wavelengths. To deal with something with quantised bands in the context of Planck's Law, you'd have to introduce a wavelength-dependent emissivity.
124220. suibhne at 23:07 PM on 12 February 2010
        Is CO2 a pollutant?
        I still cannot get my head around the idea that co2 gas with two significant quantised IR bands can radiate in a way explained by Stephen Boltzman equation!
124221. Riccardo at 22:17 PM on 12 February 2010
        How do we know CO2 is causing warming?
        clayco, the meaning looks pretty clear. "changes of 1 Watt per meter squared (or more) in the longwave fluxes that we examined in Pielke and Matsui (2005) are realistic" because it has been found by Philipona et al to be 1.8 W/m2. So it's quoted in support of their number. No sign of dispute at all.
124222. Berényi Péter at 21:50 PM on 12 February 2010
        Is CO2 a pollutant?
        #35 carrot eater at 12:13 PM on 12 February, 2010 "Breathing merely re-circulates carbon that's already in the system" Carbon atoms are not labelled. If you are to decrease CO2 levels, it is as good to push carbon into a resevoir as to stop pulling it out from another. Provided we stop breathing, we would not need freedom fries either. Potatoes could be dumped into anoxic abyss of the Black sea and the planet would be saved.
124223. rocco at 21:50 PM on 12 February 2010
        Is CO2 a pollutant?
        RSVP: "Again, keeping in mind the situation on Mars, try to imagine how much warmer the Earth would be with and without those 2 meters of CO2." Or better yet, lets use actual climate sensitivity estimates! http://www.skepticalscience.com/climate-sensitivity.htm :) Also this - "All AGW positive "radiative forcing" is coming from the extra 100 ppm, not 380 ppm" is untrue. There are even more powerful anthropogenic greenhouse gases (but their concentrations are much lower) http://en.wikipedia.org/wiki/File:Radiative-forcings.svg rrvau: You are at the right place - click "arguments" and find your answers.
124224. clayco at 21:48 PM on 12 February 2010
        How do we know CO2 is causing warming?
        J COOK say: "Pielke isn't disputing the results of Philipona 2004 - I suggest you read the post you link to." ???????? http://pielkeclimatesci.wordpress.com/2009/09/29/observational-evidence-of-a-change-of-surface-radiative-forcing-in-a-paper-philipona-et-al-2004/ "This paper (Philipona 2004) documents that changes of 1 Watt per meter squared (or more) in the longwave fluxes that we examined in Pielke and Matsui (2005) are realistic. The Klotzbach-Pielke et al. (2009) paper demonstrates that a significant bias is introduced in the land portion of the global surface temperature trend which is used in the assessment of global warming, that can be explained, at least in part, due to such changes in longwave radiative fluxes at night"
124225. Riccardo at 21:36 PM on 12 February 2010
        Could climate shifts be causing global warming?
        Patrick 027, if you look at Swanson 2009 paper (fig. 1B), you will see the various part of the oceans that influence multidecadal variability; the North Atlantic is included, although with a lower weight than the tropical pacific ocean. As for the synchronization of the modes of variability, it's purely empirical. The idea of climate shift itself, i.e. the climate system as a sort of bystable system, is just postulated. Given the complexity of the teleconnections between the various (so called) oscillations, they do not even try a deterministic approach nor a statistical analysis. They just rely on observations to calculate the influence of these oscillations on the global mean temperature and end up with their fig. 2B (Swanson 2009).
124226. CBDunkerson at 19:49 PM on 12 February 2010
        Is CO2 a pollutant?
        It is interesting to note that if the graph in the article extended back another 2000 years or so it would show that in that time period CO2 levels rose just about the same amount, 100 ppm, as they have in the past 200... which was the difference between the coldest part of the last ice age and the warmth of the current interglacial. We humans have now pushed CO2 that much higher again in 1/10th the time it took to happen naturally. At the current rate of increase it'll only take about 60 years to hit ANOTHER 100 ppm increase. Those insisting that this CO2 is not a 'pollutant' or that the effect it is having on the oceans should not be called 'acidification' are in truth attempting to redefine the longstanding accepted meanings of both terms.
124227. Timothy Chase at 19:27 PM on 12 February 2010
        Could climate shifts be causing global warming?
        Parallel Lines, Part II of II Looking on page 9 of Chou's presentation:

        Rationale of satellite water vapor retrievals * Radiation measured by the satellite in channels with various opacities comes from different regions in the atmosphere. * The radiation measured in more transparent channels originates from lower atmosphere, and the radiation measured in less transparent channels originates from higher atmosphere. * Therefore, radiation measured in a number of channels with different opacity provides information on temperature and water vapor at different levels of the atmosphere. ibid, pg. 9

        Stated in very basic terms, this is precisely what I concluded from my understanding of Kirchoff's law. Judging from this, no complex model is necessary. I see some mention of the use of "GPS Radio Occultation Measurements" where they need to identify the position of the satellite on the sweeps (pg.11) -- but one would expect that from a moving satellite. There are some complexities to that, for example, having to do with the bending of radio signals as they pass through the atmosphere at an angle. On page 10 there is mention of limb observations where the AIRS is being used to peer through the atmosphere almost parallel to the surface. There is some employment of geometry and some modeling (I presume) involved in limb observations -- with the air pressure and density of the atmosphere and the partial pressures of the greenhouse gases going from low to high to low. This, I presume, is a rarer use case. Page 13 is titled "AIRS and NCEP/NCAR Reanalyses (Global water vapor data sets)." It states that reanalyses "assimilate satellite and other observations." Seems accurate enough. In contrast what I take to be the more common use case would involve the air pressure and density of the atmosphere and the partial pressures of the greenhouse gases going strictly from high to low where the satellite is directly overhead of the atmosphere it is imaging. What was mentioned on page 9 and the use case to which I was applying Kirchoff's law. But it most certainly does not involve using a climate or weather model to interpret the sensory data of a satellite. I also notice that there are some comparisons of AIRS and FORMOSAT results on pages 16 (pretty much spot-on), 17 (same basic shape, but somewhat higher levels of water vapor from Formosat in the tropics). AIRS and FC differ by perhaps as much as 20% on water vapor as grams per kilogram at the 350 and 650 hPa levels. Particularly around the poles (which would be closer to limb measurements I presume) although to some extent in the tropics. The difference I presume is most likely a matter of the specific channels being used. Perhaps some sensitivity on the part of the instruments, orbital variation, etc.. Anyway, I see various somewhat vague assertions. Satellite microwave observations are referred to as "a priori" information. Would that be the same satellite? Are we talking about height? Orbit? Vague. I don't see much of anything in terms of actual references in Chou's presentation. Not really to be expected since this is only a presentation, not a peer-reviewed paper. * Berényi Péter wrote in 45:

        So. The question still stands. To what extent "measured" (actually: calculated) values are dependent on model? For the general idea, still used in AIRS reconstructions see: High resolution observations of free tropospheric humidity from METEOSAT over the Indian Ocean. R´emy Roca, H´el`ene Brogniez, Laurence Picon and Michel Desbois Laboratoire de M´et´eorologie Dynamique, CNRS, Palaiseau, France MEGHA-TROPIQUES 2nd Scientific Workshop, 2-6 July 2001, Paris, France.

        Regarding METEOSAT:

        The retrieval algorithm is similar to the operational algorithm run at EUMETSAT with slight modifications in the interpretation of the inverted signal. It relies on the use of local look up table and radiative transfer computations. The ancillary data needed for the algorithm are composed of the temperature profile taken from the ECMWF analysis. The final product is the weighting function weighted mean relative humidity over the free troposphere (FTH). Remy Roca, et al. (2001) High resolution observations of free tropospheric humidity from METEOSAT over the Indian Ocean, MEGHA-TROPIQUES 2nd Scientific Workshop, 2-6 July 2001, Paris, France http://meghatropiques.ipsl.polytechnique.fr/dmdocuments/proc_s2p06.pdf

        So if AIRS did things the same way as METEOSAT (as you tell us that it does) then the one thing it requires is the temperature profile from ECMWF analysis -- where ECMWF may be the weather model or:

        The European Centre for Medium-Range Weather Forecasts (ECMWF, the Centre) is an international organisation supported by 31 States, based in Reading, west of London, in the United Kingdom. http://www.ecmwf.int/about/

        ... the weather agency. Assuming it is the model we still aren't trying to identify a unique state that gives rise to the "radiation signature." Each Radiation line could be handled individually. And all that is required of your complicated model is the temperature profile. However, going back to Chou's presentation, page 20:

        Satellite observations of radiance and radiowave occultation are sensitive to both water vapor and temperature. It requires accurate retrievals of temperature prior to retrieving water vapor.

        It would seem that AIRS can calculate its own temperature profiles -- but perhaps he is simply referring to temperature being retrieved by "something" prior to the use of temperature in the determination of water vapor content. I dug a little further...

        Level 2 Algorithm Theoretical Basis Document (ATBD) Describes the theoretical basis of the AIRS Level 2 Products Algorithm. Many products are presented in one document because of the basic structure and approach of the Level 2 Products Algorithm. In order to achieve the basic requirement of temperature profile accuracy of 1K in 1 km thick tropospheric layers, a multi-spectral simultaneous retrieval of both the atmospheric thermodynamic state and atmospheric composition is attempted. Hence the Level 2 Products refer to the basic thermodynamic variables and trace gas abundance that control the outgoing infrared radiance. http://airs.jpl.nasa.gov/data_products/algorithms/

        Not saying that is what they generally use -- but it would appear that they do not need a weather model for the determination of temperature profile. And that sounds to me like "Consequently, given enough channels and enough unique absorption lines one could peel back the layers of the atmosphere like an onion.... Given my analysis it would seem that there is no need for some sort of all-purpose model for computing one unique physical state that would produce the specific full spectrum. All you need are a certain set of well-chosen frequencies for the particular problem at hand." That is, what I concluded given Kirchoff's Law. * Berényi Péter wrote in 45:

        As for the multitude of spectral channels. Some women are tetrachromats. I don't think they can grasp reality more accurately than anyone else. Myopic girls could do worse.

        I don't believe there has been even a single verified case of this -- although two women have been suspected tetrachromats. But maybe you know differently. I have to admit I was hoping you got that one right. Would have been fascinating. * Berényi Péter wrote in 45:

        As for doubting Descartes, consider the following tiny piece: ...

        Might want to re-examine what you wrote in step 2. Additionally, I somehow doubt that "senselessness" is an epistemic term. Would the law of identity be "senseless" since a contradiction does not make sense? What about 2+2=4? Does it fail to make sense since 2+2=5 fails to? In any case, I think Descartes' self-referential argument was the one thing he got right. Otherwise, my interest in him lies primarily in understanding his influence upon later thinkers -- including Kant.
124228. Timothy Chase at 19:23 PM on 12 February 2010
        Could climate shifts be causing global warming?
        Parallel Lines, Part I of II Berényi Péter wrote in 45:

        The tricky part is to restrict the definition domain so as to make the transform invertible. It is done by constructing a model that does not allow for just any combination of state variables, but only a tiny subset, and if you are lucky, all states conforming to model would generate different radiation output.

        In 47, I responded in part:

        By Kirchoff's law we know that what radiation emit they will also absorb, so if the radiation escapes to space along a given absorption line that is saturated below a given altitude, then it must be escaping where saturation gives way to transparency, that is, where the gas ceases to be "opaque" to radiation at that particular frequency. This should be independent of the radiation being transmitted at that frequency in the lower layers of the atmosphere as all radiation will be absorbed at saturation, and the emission of radiation, assuming conditions of local thermodynamic equilibrium -- will be strictly dependent upon the intrinsic properties of the matter -- including its temperature. Consequently, given enough channels and enough unique absorption lines one could peel back the layers of the atmosphere like an onion.

        * Berényi Péter wrote in 45:

        It is _actually_ the approach they are using to reconstruct upper/mid troposphere relative humidity distributions using AIRS spectra. The algorithm IS dependent on the (rather complicated) ECMWF global atmospheric model. European Centre for Medium-Range Weather Forecasts ECMWF general circulation model (TL799L91) Other than the hyperlinks to material on the weather model itself, the webpage you just referred us to states:

        The ECMWF global atmospheric model The ECMWF general circulation model, TL799L91, consists of a dynamical component, a physical component and a coupled ocean wave component. The model formulation can be summarised by six basic physical equations, the way the numerical computations are carried out and the resolution in time and space.

        I am not seeing anything on AIRS Atmospheric InfraRed Sounder or its "use" of a weather model in order to make sense of it sensory data. Nor does it make any sense whatsoever to expect such material. * Berényi Péter wrote in 45:

        It is not just philosophy, but a hard fact of life. Have a look at this recent presentation: Ming-Dah Chou(3 February 2010) Applications of Satellite Water Vapor Retrievals to Climate Studies, Presentation at the Research Center for Environmental Changes, Academia Sinica, February 3, 2010. http://www.rcec.sinica.edu.tw/Seminar%20files/Presentation%20files/100203(Dr.%20Edward%20Cook)Satellite%20Water%20Vapor%20Retrievals.pdf

        This would be Ming-Dah Chou, one of Richard Lindzen's coauthors in: Lindzen, R.S., M.-D. Chou, and A.Y. Hou (2001) Does the Earth have an adaptive infrared iris? Bull. Amer. Met. Soc., 82, 417-432 ... I take it. * Berényi Péter wrote in 45:

        From "Concluding Remarks": - Global distributions of water vapor can be best derived from Satellite observations. - However, satellite retrievals of water vapor in the upper and lower troposphere encounter inherent difficulties, and the satellite-retrieved water vapor in these important regions is not reliable.

        One of the coauthors of the adapted infrared iris? This conclusion doesn't seem that surprising -- given the unfavorable light that satellite observation has cast on the hypothesis. Please see for example:

        [23] The existence of a strong and positive water-vapor feedback means that projected business-as-usual greenhouse gas emissions over the next century are virtually guaranteed to produce warming of several degrees Celsius. The only way that will not happen is if a strong, negative, and currently unknown feedback is discovered somewhere in our climate system. A. E. Dessler, et al. (23 Oct 2008) Water-vapor climate feedback inferred from climate fluctuations, 2003–2008, Geophysical Research Letters, Vol 35, L20704, pp. 1-4 http://geotest.tamu.edu/userfiles/216/Dessler2008b.pdf

        However, did you look into the reasoning that went into the conclusions you quote?

124229. RSVP at 18:39 PM on 12 February 2010
        Is CO2 a pollutant?
        Referring to the graph, it should be noted that proponents of AGW do not attribute global warming to 380 ppm CO2, but to the 100 ppm difference in concentration relative to where it was 200 years ago. (All AGW positive "radiative forcing" is coming from the extra 100 ppm, not 380 ppm.) Going back to my spreadsheet, 100 ppm yields a 2 meter coverage of CO2 over the Earth (as calculated assuming 20 km of normal air). Again, keeping in mind the situation on Mars, try to imagine how much warmer the Earth would be with and without those 2 meters of CO2. As on Mars, for all practical purposes, the effect would be nil. However, since the Earth would be receiving more sunlight, and is covered with water, the situation would be very different. It would be a warmer place, not because the CO2, but because of the water.
124230. Patrick 027 at 15:56 PM on 12 February 2010
        Could climate shifts be causing global warming?
        ... Looks like a very interesting discussion, I look forward to reading some of the comments above. Just to mention a few things: 1. I thought the AMO might account for some of the unforced multidecadal variability in the record, but so far as I know, Tsonis et al did not look at AMO ... did I miss something? Supposing AMO turns out to be the big contributor, why would other modes synchonize specifically at the extrema of AMO or value ranges of the AMO index? Would AMO be the driver or would there be a more complex interplay? If it isn't AMO, how would synchronization at one time cause a temperature trend afterward and not just during? Where is the hysterisis/whatever mechanism? Is the idea that when in a cooling phase, the climate system has been reorganized such that equilibrium has dropped and it is approaching a cooler equilibrium (defined by short-term conditions, whereas the longer-term effects disrupt such an equilibrium but still allow a longer-term equilibrium state that encompasses the internal variability), but then at some point on this approach some negative feedback starts up that shifts the climate system so that the equilibrium is warmer, etc.? I recall once-upon-a-time reading something like the AMO might be caused by variations in salinity in the North Atlantic related to water exchanges with the Mediterranean; I don't remember the proposed mechanism, but trying to put something coherent together right now: perhaps faster flow through the Atlantic would reduce the salinity by diluting the Mediterranean contribution, which would slow the flow through the Atlantic, which would increase the salinity, etc, on a time scale characteristic of the residence time of water within the North Atlantic surface water??? ----- Question loosely related to water vapor feedbacks: I had been under the impression that with greenhouse-forced global warming in general, the tropopause level would tend to cool (the increased height would over-compensate for the surface warming + lapse rate change. Conceivably, this could cause (if the cooling is enough relative to the pressure change, because it is the mixing ratio and not the vapor pressure that actually matters here) some introduction of dryer air (lower specific humidity) into the troposphere (PS more severe thunderstorms?). I hasten to add that this could still be overwhelmed by the greater water vapor mixing ratios from lower level outflows from moist convection, etc, depending on the math... then again, the effect of warming at a given pressure level would be somewhat reduced by an increase in the height of the distribution of inflow and outflow from moist convection following (in proportion or not?) the thickenning of the troposphere. Of course, the thicker troposphere and the cooler tropopause level would both add positive feedbacks (including via cloud tops) - would they balance out the reduction in water vapor concentration they MIGHT cause? Well I wouldn't know enough of the input paramers, etc, to do the calculation, and sense this is purely hypothetical on my part, might as well go with the model output and the observations, and you know how those go... BUT I recently got the impression that am/was wrong about the tropopause level temperature trend, as I saw a paper abstract which suggested that ozone depletion would cause tropopause-level cooling but greenhouse forcing in general would leave the tropopause level isothermal (as stratospheric cooling is more pronounced at higher levels, but this still surprises me a little because I thought at least some nonzero stratospheric cooling was expected down to the tropopause level) (following equilibrium, presumably - disequilibrium might be otherwise)... So I'm wondering, what is actually expected for tropopause level (pressure) and temperature changes for 1. a doubling of CO2, 2. equivalent solar forcing? Berényi Péter Some women are tetrachromats. I assume this alludes to the two different kinds of red cones, and that some people have both types. I've wondered if they could tell, though, or if the two types are too similar in their spectrums and responses? Interestingly, many animals outside of mammals have tetrachromatic vision, while most mammals have less than (numerically) trichromatic vision.
124231. yocta at 15:42 PM on 12 February 2010
        Is CO2 a pollutant?
        There is a lack of carbon-14 in fossil fuels and the isotopic ratio of CO2 in the atmosphere due is changing as a result of its release into the atmosphere. If you could some how bring in the labeling of "pollutant" with regard to this changing ratio that would make more sense.
124232. neilrieck at 15:02 PM on 12 February 2010
        Is CO2 a pollutant?
        John Gribbin's book "He Knew He Was Right" states that one of NASA's criteria for off-Earth life involves "looking for planetary atmospheres with a low percentage of CO2". Mars doesn't have much of an atmosphere but what is there is mostly CO2 (so no life). Venus has a hot thick atmosphere with high levels of CO2 (so no life). On Earth, plant life far outweighs the animal life so low levels of CO2 along with high levels of O2 mean that the plant life is successfully converting the former into the latter (along with cool oceans sinking much of the balance of CO2). When temperature gets too hot, the oceans can't hold very much gas so CO2 gets much higher. Likewise volcanoes belch a lot of CO2 and this can add to the imbalance.
124233. Marcus at 14:07 PM on 12 February 2010
        Is CO2 a pollutant?
        The point, here, is that we're adding CO2 into the system which was *removed* from the system hundreds of millions of years ago. It is this CO2, alone, which we need to regulate. Its also much easier to do than some would have us believe. If we used bio-sequestration, we could significantly reduce the net CO2 emissions of coal & natural gas power stations. If we increase our use of non-fossil fuel derived sources of fuel & electricity (solar, biogas, wind, tidal etc etc) then we could significantly reduce the gCO2/kw-h that our economies create. Lastly, if we become much more *efficient* in our use of fuel & electricity, we can significantly reduce the amount of kw-h/$ of GDP necessary to sustain our economy.
124234. thingadonta at 12:34 PM on 12 February 2010
        Is CO2 a pollutant?
        re carrot eater "The EPA labeling something as a pollutant, under the language of the Clean Air Act and with the approval of the Supreme Court, has no particular philosophical implications". I disagree. It's labelling, and leads to systematic bias and dogma. You can regulate something without labelling it, eg cars arent labelled a 'dangerous moving object', and yet they are still regulated.
124235. carrot eater at 12:13 PM on 12 February 2010
        Is CO2 a pollutant?
        thingadonta: I don't follow your point. The EPA labeling something as a pollutant, under the language of the Clean Air Act and with the approval of the Supreme Court, has no particular philosophical implications. It merely sets the process towards the EPA being able to regulate its emissions. And Berenyi, breathing is completely irrelevant to the topic. What's relevant are activities that introduce extra carbon to the carbon cycle. Breathing merely re-circulates carbon that's already in the system.
124236. carrot eater at 12:06 PM on 12 February 2010
        Is CO2 a pollutant?
        Ugh. There's nothing worse than misplaced pedantry. Would somebody please inform the sceptics that they aren't being clever when they harp on the usage of the word 'acid'. If the pH is decreasing, something is becoming more acidic. Period.
124237. Doug Bostrom at 10:59 AM on 12 February 2010
        Is CO2 a pollutant?
        Not to belabor a point, but it seems we're continuing to make tangelos out of tangerines and oranges here. Fish oil in a fish is natural, part of the natural world, undoubtedly necessary and good. 5000 gallons of fish oil spilled in a harbor is a pollutant, damaging, and is under the purview of the EPA.
124238. foram at 10:49 AM on 12 February 2010
        Is CO2 a pollutant?
        "All the surface waters of the world are carbonate-saturated." Yes, you'll find a nice diagram illustrating just that on p.7 of the Royal Society report (link at 8, above). What's your point?
124239. Steve L at 10:46 AM on 12 February 2010
        Is CO2 a pollutant?
        People like to make a big deal of whether or not acidification can occur above pH 7. It's silly. As are claims that "acidification" was designed for alarmist purposes (look at the alternative labels for the phenomenon). What matters is deviation from conditions to which organisms have evolved. This is certainly changing, and rather rapidly too. Industrial activity has increased the activity of hydrogen ions near the ocean's surface by about 25% I believe. Whether or not carbonate is at saturating levels is not the only concern, although it is certainly something to consider. It's expected that for aragonite the saturation horizon will go from 730 m up to the surface over the course of this century and from 120 m up to the surface in the sub-Arctic Pacific (apparently in Orr et al 2005 -- I haven't read it yet). In the North Atlantic, 2600 m up to 150 m is expected. These changes pose a very serious challenge to many calcareous animals. But effects will be seen long before the saturation horizon ascends to shallower depths than where the creatures live. See this Wooten et al paper in PNAS for example: http://www.pnas.org/content/105/48/18848.full.pdf+html Look at Figure 2B. Now think about what's going to happen when atmospheric CO2 is at 500 ppm? Very big changes to ocean chemistry and consequent effects on ocean creatures. And we're headed there much too quickly.
124240. stevecarsonr at 10:44 AM on 12 February 2010
        Is CO2 a pollutant?
        I agree with thingadonta #28. It will end up being a net negative for those seeking to prevent "climate change".
124241. Craig Allen at 10:35 AM on 12 February 2010
        Skeptical Science now an iPhone app
        Once you have installed the app on your iPhone, make sure you go back into the iPhone application store and give it a rating!
124242. Doug Bostrom at 10:32 AM on 12 February 2010
        Is CO2 a pollutant?
        "Acidification is a misnomer, designed to conjure scare up." No, you're wrong. Regardless of where on the scale of pH a change takes place, a decrease of pH reading is best and most concisely termed "acidification". A lower pH reading is more acid, a higher pH reading is more alkali and there is no threshold for the use of either term. A change in pH reading from 10 to 9 is considered acidification even though the resulting number describes a base. Just so, a change from a reading of 2 to 3 is considered alkalinification (or the less used "basification") even though the result is still acid. Researchers using the term "acidification" have little choice in the matter. The alternative would be to use the more clumsy phrase "reduction of pH value" or a variation thereof. I don't think these folks care enough about politics to do that, they'll instead stick with the accepted parlance.
124243. thingadonta at 10:15 AM on 12 February 2010
        Is CO2 a pollutant?
        "The net result from increasing CO2 are severe negative impacts on our environment and the living conditions of future humanity." I agree with the general view that if most climate scientists are right, the net effects of c02 will be very negative. However, the issue here is a general philosphical one. By labelling and demonising something natural and essential to life as a 'pollutant', is a dangerous and misleading policy. It creates a dogmatic, one-sided political perspective. As David Haughton points out, you could also call water a 'pollutant' using this sort of labelling. If too much is ingested in the lungs, one drowns, it can form hurricanes which kill thousands of people, it can form tsunami waves that kill thousands, etc etc, so should we call 'water' a pollutant and form policies against it? Of course not. It is misleading and dangerous to do such a thing, regardless of its overall net positive or negative effects. Labelling C02 a pollutant may achieve political goals, but at the expense of also creating a dogmatic perspective. What this sort of general policy does to the mind (as also with Plato and with his concept of a Republic run by an elite-he never asked what such an arrangemnet does to the mind of those involved), is that is creates systematic bias and extremism. It is the same kind of problem with eg demonising dissent, dissent of course can be very wrong, but it can also have value, but the demonisation of dissent as a general policy is what is wrong. I'm sorry, but it is just another case of 'lumping' which is a general philosophical issue that some people have a valid disagreement with.
124244. Berényi Péter at 09:49 AM on 12 February 2010
        Is CO2 a pollutant?
        Posted by John Cook at 22:54 PM (main article): "as the oceans absorb CO2 from the atmosphere, it leads to acidification that affects many marine ecosystems" Seawater is nowhere near to being acidic, not even neutral. It is alkaline. No conceivable CO2 levels could turn it into an acid. Acidification is a misnomer, designed to conjure scare up. The process can honestly be described as dealkalinification, at best. All the surface waters of the world are carbonate-saturated. The lysocline, where calcium carbonate solubility starts to increase sharply is somewhere around 3700 m. The CCD (Carbonate Compensation Depth), below which no limestone deposition occurs is at 4200-5000 m. It didn't change much during glacial periods, when atmospheric CO2 levels are supposed to be considerably lower than today. Kinda enigma, see: Glacial/interglacial variations in atmospheric carbon dioxide (review article) Daniel M. Sigman & Edward A. Boyle http://www.up.ethz.ch/education/biogeochem_cycles/reading_list/sigman_nat_00.pdf With water warming, lysocline goes down, not up. If all else fails, we can put some limestone into oceans to balance CO2. There are several million gigatons of it in crust, a tiny little percentage would suffice.
124245. angliss at 08:32 AM on 12 February 2010
        Is CO2 a pollutant?
        Thank you for the explanation, RSVP. That's what I thought you probably were going for, but I wanted to be sure before I attempted to respond with a scientific rebuttal. However, CBDunkerson has already made the very points I would have made and I feel no need to reiterate his points. Ed Seedhouse - I think you meant carbon dioxide, not carbon monoxide.
124246. Doug Bostrom at 08:30 AM on 12 February 2010
        Is CO2 a pollutant?
        David Horton at 08:05 AM on 12 February, 2010 David, I get what you're saying, but the analogy with water from a tsunami or other natural event really does not work. I even disagree with our host when he says: "How we choose to define the word 'pollutant' is a play in semantics." The CO2 in question here is an effluent from human activities. Our C02 emissions are an outcome of our engineered products, something we now realize is a serious imperfection. As another example, C0 is found naturally occurring in the atmosphere yet we have spent a lot of money improving our motor vehicle engineering so that we do not emit too much C0. We do not accept that because C0 is a naturally occurring atmospheric constituent that we may ignore the C0 we produce as a byproduct of our activities. EPA's job is going to be explaining that simple fact, but the job of explanation is going to be very difficult given the call to confusion they'll be facing from industry.
124247. David Horton at 08:05 AM on 12 February 2010
        Is CO2 a pollutant?
        Thanks for putting in this topic John. It is one of those pieces of semantic nonsense (how many CO2 molecules could you fit on the head of a pin?) that are trotted out by deniers as if discovering some new universal truth hitherto covered up by the secret scientific brotherhood. On a practical level my understanding is that the American EPA, and possibly other countries are in the same position, can only regulate to reduce "pollutants" in air soil and water. It was never envisaged when such bodies were being established that CO2 would be become the most important issue of all and need controlling. The simplest thing would be to rewrite legislation to say "control pollutants AND CO2" and that would get us away from semantic games. I mean clearly CO2 isn't a pollutant in the classical sense. Nor is water. And yet water, after a flood, or a landslide, or a tsunami, damages human environments as much as any chemical released from factory or oil tanker. So too much water, too quickly, in the wrong place at the wrong time, is a damaging agent in the same way that pollutants from an oil tanker crash, or a factory fire, are damaging agents. It is all reminiscent of the old debate about what is a "weed". Definitions usually break down at some point and we are usually left with just the idea that a weed is a plant growing rapidly in the wrong place. So perhaps it would be helpful to refer to CO2 as a chemical weed rather than a pollutant. That might stop the deniers dancing on the heads of pins.
124248. Dennis at 07:52 AM on 12 February 2010
        Is CO2 a pollutant?
        Alexandre writes: "Anything can be a pollutant, in the wrong concentration." This is a good way to look at it, and an excellent analogy is to think of drugs and other medications. In the correct dosage, a drug can save your life. But too much of it can kill you. Same with CO2
124249. From Peru at 07:14 AM on 12 February 2010
        Is CO2 a pollutant?
        CO2 is toxic to subwater organisms, because the following reaction occurs: CO2(ac)+H20(l)=H2CO3(ac) H2CO3(ac)= H+(ac) + HCO3-(ac) Yes, seawater has a natural pH buffer thanks to all the salts there(the so-called alkalinity), but the quantity of CO2 we emit is so big that this buffer is overwhelmed. In consecuence, oceanic pH has dropped 0,1 pH units from pre-industrial times(pH used to be 8,2. now is 8,1). This is equal to roughly 30% increase in acidity!(don't forget that pH is a logarithmic scale). More acidic water means that shelled creatures like corals, pteropods, diatoms, etc, will lose their shells and die. This alone is more than enough to consider CO2 a pollutant, even if we ignore global warming!
124250. Doug Bostrom at 06:53 AM on 12 February 2010
        Is CO2 a pollutant?
        RSVP at 05:21 AM on 12 February, 2010 For chronic exposure, even lower. Some folks become symptomatic at less than 2,500ppm after a relatively brief time, but if we were to somehow hit that we'd all be cooked anyway.

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