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Comments 124351 to 124400:

  1. 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.
  2. 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.
  3. 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?
  4. 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.
  5. 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.
  6. 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.
  7. 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.
  8. 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.
  9. 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.
  10. 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.
  11. 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.
  12. 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.
  13. 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?
  14. 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.
  15. Is CO2 a pollutant?
    I agree with thingadonta #28. It will end up being a net negative for those seeking to prevent "climate change".
  16. 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!
  17. 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.
  18. 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.
  19. 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.
  20. 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.
  21. 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.
  22. 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.
  23. 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
  24. 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!
  25. 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.
  26. Is CO2 a pollutant?
    RSVP, it is true that the atmosphere of Mars is 95% carbon dioxide... but the mass of the Martian atmosphere is only 0.5% that of Earth. Further, Mars does not have any significant component of water vapor in its atmosphere. That, combined with Mars getting about 43% as much sunlight is responsible for its cold temperatures. The high percentage of CO2 in the Martian atmosphere DOES provide a greenhouse effect. Just not enough to overcome the low amount of sunlight and lack of much more potent water vapor greenhouse warming.
  27. Is CO2 a pollutant?
    Anything which causes damage to an ecosystem when it grows too concentrated is a pollutant. Thus we have "light pollution" and "noise pollution" despite light and sound being 'naturally occurring' and generally harmless things. Early in the planet's history "oxygen pollution" wiped out alot of species. A single molecule of CO2, or just about any other substance, is not going to noticeably harm the environment in any way... but 80,000 ppm CO2 would kill off most life on the planet. Thus, somewhere between those extremes CO2 logically MUST be considered to become a pollutant. It is a measured fact that increased CO2 emissions have changed the pH of the shallows of the world's oceans. This change has clearly had an adverse impact on species living there. Thus, human CO2 emissions have become a pollutant for the ecosystems of the upper portions of the world's oceans. Likewise, rising global temperatures have been linked to the increasing atmospheric carbon dioxide level... and those rising temperatures are having adverse impacts on countless ecosystems all over the world. Thus, atmospheric CO2 has reached levels where it has become a pollutant for many parts of the planet. Granted, there are many other areas which have suffered no significant adverse impacts from increasing CO2 levels yet. However, since CO2 released in one part of the planet can mix throughout the atmosphere in a matter of mere months this means that release of CO2 anywhere on the planet is contributing to the harm in areas being polluted by it... similar to acid rain from sulfur dioxide (another naturally occurring substance which only becomes a pollutant at high concentrations) appearing far removed from the emissions source.
  28. Is CO2 a pollutant?
    "angliss at 05:35 AM on 12 February, 2010 RSVP - I don't see what the point of your Mars atmosphere comment was. Can you clarify your purpose with that comment?" While I believe there is such a thing as thermal environmental pollution, I am personally not convinced (yet) that anthropogenic CO2 is the main cause of global warming. One way to look at this is by comparing the situation on Mars, which happens to also have a 24 hr day, and an atmosphere of pure CO2 that is just about the same as would exist on the Earth if all other gases from our atmosphere were removed (which is the point of explaining my calculations). On Mars, the average temperature is down around -40C. And yes, I am aware that Mars only gets about half the sunshine as the Earth, however, shouldnt all that CO2 be keeping the plantet a little warmer?
  29. Is CO2 a pollutant?
    Venus, too, like Mars, has an atmosphere of nearly pure carbon monoxide. Yet it, unlike Mars, is hellishly hot. RSVP, do you suppose, that, just maybe, distance from the sun has some slight influence here?
  30. Is CO2 a pollutant?
    As with so many other aspects of the climate change debate, the question of whether CO2 should be regarded as a pollutant has become more an issue of politics and ideology than of science. An interesting analysis and discussion can be found in the United States Supreme Court decision in Massachusetts et al. v. EPA et al.: http://www.law.cornell.edu/supct/pdf/05-1120P.ZO At the time, the U.S. Environmental Protection Agency, acting on behalf of the Bush Administration, declined to regard CO2 as a pollutant that could potentially be regulated under the Clean Air Act. The Supreme Court split 5-4, along ideological lines. See p. 26 for discussion of the term "pollutant". The political nature of this dispute is further evident in that the plaintiffs included 11 (2004) "Blue States" plus one Red State (New Mexico), while the EPA was joined by 9 (2004) "Red States" plus one Blue State (Michigan, capital of the auto industry!).
  31. Is CO2 a pollutant?
    RSVP - I don't see what the point of your Mars atmosphere comment was. Can you clarify your purpose with that comment? CoalGeologist - as you point out, "pollutant" also depends on source. An example I like to use is fixed nitrogen. It's a vital soil nutrient - but becomes a pollutant when there's too much of it spread on fields and the excess flows down the Mississippi and into the Gulf of Mexico, where it fuels algae blooms and a massive dead zone.
  32. Is CO2 a pollutant?
    This entire discussion is missing the required context. People may differ on how they use the word 'pollutant', but in the US the issue goes back to this Supreme Court case: http://en.wikipedia.org/wiki/Massachusetts_v._Environmental_Protection_Agency The Supreme Court found that CO2 qualifies as a pollutant, as defined by the Clean Air Act. Regardless of whether you want to use the word 'pollutant' or not, increased CO2 levels have adverse effects which qualify them for regulation under the Clean Air Act.
  33. Is CO2 a pollutant?
    In many posts on many websites, deniers try constantly to make the people concerned about human impact on the climate admit that they think of CO2 as a pollutant (which is of course why John addressed the question here). Their reasons then become clear when, with denier's glee, they come back with, "...but it's necessary to support life on Earth!" It's just another of the many carefully rehearsed tricks that deniers use against those with a shaky understanding of the causes of climate change, in order to undermine their trust in the findings of climate scientists. Unfortunately at the moment the science of the 'blindingly obvious*' used by deniers seems to be winning the battle for public opinion. *'blindingly obvious' is the phrase used by arch-denier Lord Monckton to describe the evidence against AGW.
  34. Is CO2 a pollutant?
    CO2 can actually be toxic to humans at or above 50,000 ppm. See link: http://www.inspectapedia.com/hazmat/CO2gashaz.htm
  35. Is CO2 a pollutant?
    Part of the ambiguity in the term "pollutant" is that a distinction needs to be made between the [quantity of] CO2 represented by the flat part of the curve above versus the incremental CO2 introduced as a by-product of human activity ("anthropogenic CO2"): same molecule, different origin. We encounter an analogous (intentional?!) ambiguity when skeptics use the term "global warming" to describe all warming that has occurred: a) since the last glacial maximum (~22,000 years before present) or b) since the LIA. It is not simply CO2 but A-CO2 that is interpreted to be driving anthropogenic warming (AGW), and thus is acting as a "pollutant". The other potential ambiguity is that the harmful impact of A-CO2 needs to be measured relative to the "status quo", which refers specifically to the climate and environment that has existed for the several thousand years prior to human impact on climate. This is a "blink of an eye", geologically. During the time period preceding the curve shown depicted above, both CO2 and temperature varied substantially in response to natural drivers. This partly explains why many geologists see climate change in different context.
  36. Berényi Péter at 03:37 AM on 12 February 2010
    Could climate shifts be causing global warming?
    #47 Timothy Chase at 17:58 PM on 11 February, 2010: "Initially sounds like it could be a reasonable approach" 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) It is not just philosophy, but a hard fact of life. Have a look at this recent presentation: Applications of Satellite Water Vapor Retrievals to Climate Studies Ming-Dah Chou Department of Atmospheric Sciences National Central University 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 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. 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. --- At another site, another time I would happily discuss the intricacies of phylosophy. However, it looks a bit off-topic here. 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. Anyway, image processing skills of the soul are not understood. On the other hand, things in science are supposed to be understandable. As for doubting Descartes, consider the following tiny piece: 1. If a subphrase of a phrase does not make sense, the entire phrase is senseless. 2. Senselessness is preserved by negation. 3. The negation of "I think (therefore) I am" is "I am not (therefore) I don't think". 4. The phrase "I am not" does not make sense Therefore: Chartesian philosophy is based on nonsense. Google for it. http://www.google.com/#hl=en&q=%22I+am+not%22 --- AIRS fact sheet
  37. Is CO2 a pollutant?
    Republican Rep. Mike Noel (Utah): "Are you stating on record that CO2 is a pollutant? Are you saying that CO2, carbon dioxide, is a pollutant, are you saying that?” Professor Joseph Andrade: "I'm saying that carbon dioxide has a unique molecular structure which absorbs infrared radiation, and that that is in part responsible for the effects that you're concerned with, Representative Gibson is concerned with, and Representative ...." Noel: "I want to get this on the record, ok? Are you saying that we have to rid the planet of carbon dioxide?" Andrade: "Of course not!" Noel: "It's not a pollutant then, it's not going to kill you. It's not going to kill plants. Is that correct? I also have a degree too, professor. So I want to get this straight. Is it a pollutant?" (The conversation becomes a verbal skirmish, and the committee chairman breaks it up.) Noel: "I'm sorry, I'm sorry ... It got out of hand."
  38. Is CO2 a pollutant?
    Argh, typo. Should just say "acidification is a decrease in pH". Relatively small changes in pH are associated with significant alterations to ocean carbonate chemistry, which affects the ability of calcifying organisms (such as corals) to build their skeletons
  39. Is CO2 a pollutant?
    Westwell, a acidification is a decrease in pH. Nobody is suggesting the oceans will become acidic! You could take a look here (http://royalsociety.org/Ocean-acidification-due-to-increasing-atmospheric-carbon-dioxide/) if you are genuinely interested in learning about the issue.
  40. Is CO2 a pollutant?
    I think a key factor here is timing. We tend to think of something being a pollutant or poison if it has an immediate negative effect, as someone mentioned above. I think this is a precarious view, though. When we're talking about a substance that hangs around in the atmosphere (at least the portion not absorbed by the oceans, plants, etc.) for a very long time and can therefore build up over decades and centuries to a dangerous level, I would say that still qualifies as a pollutant. As for the "too much of anything is bad" idea--of course that's true, but if we consistently apply that guideline it leaves us doing nothing about any pollutant. The only rational approach is to distinguish between critical and non-critical levels of substances. If we call the damaging levels of something a pollutant, regardless of its source *e.g. sulfurous emissions from volcanoes), then I think that's fine. Westwell: Oceans don't acidify because of CO2 absorbed from the atmosphere? Really?
  41. Is CO2 a pollutant?
    Using figures from the graph, one can estimate the comparable height of a pure CO2 Earth atmosphere removing all other gases. For intance, if you assume an air atmosphere 20 km high, with a concentration of 0.0274 CO2 (how it used to be), you would have a CO2 atmosphere of 5.5 meters covering the Earth. If you assume 0.0387 vppm, that pure CO2 atmosphere grows to 7.8 meters. Assuming continual doubling, to 0.0774, you get 15.5 meters. If you dont like 20 km and wish to consider a higher atmosphere of 40 km for instance, then these results simply get multipled in linear fashion, so that at worst, you get roughly around 30 meters of pure CO2 covering the Earth. Ironically, that basically describes the atmosphere of Mars, which has a composition of nearly pure CO2. http://www.daviddarling.info/encyclopedia/M/Marsatmos.html ... and Mars is a very cold place. PS I derived these figures assuming the Earth as a perfect sphere, using the formula for calculating the volume of a sphere and applying it to an assumed Earth radius of 6378.1 km. No rocket science required, but I did use a computer spreadsheet.
  42. Is CO2 a pollutant?
    Yes it is semantics. But playing politics is something we do everyday, wether at work, school, internet, etc. It seems like in the USA and UK we do it for sport. But the bottom line is we have to move foward so it doesnt matter if you call it klem kaditlehopper as long as something gets done
  43. Is CO2 a pollutant?
    Re:"as the oceans absorb CO2 from the atmosphere, it leads to acidification that affects many marine ecosystems." This is not true. The oceans are buffered and the acidification does not rise from increased absorption of CO2.
  44. Berényi Péter at 00:56 AM on 12 February 2010
    Is CO2 a pollutant?
    I would reserve the term "pollutant" to stuff that 1. has got an immediate, direct harmful effect to human health and/or to quality of local environment in a way that substantially decreases property value 2. can be traced back to individual polluters, actual deed and the damage done being provable at court None of these conditions hold for carbon dioxide. If CO2 is "pollutant" what term would you reserve for e.g. dioxin, the stuff involved in the Union Carbide disaster, Bhopal, India, 1984? Thousands perished. http://lists.essential.org/dioxin-l/msg01318.html There should be a difference in legislation and multilateral treaties regarding the two kind of substances, otherwise not even overt criminals can be brought to justice. Cases like that can never be cured by taxation, virtual bonds, persuation & speeches. Also, humans do breathe out CO2, a substantial amount of it (up to 300 kg/year/person, ~2 Gt/year for mankind). If polluting is declared a criminal act (as it should have) and human breath is a pollutant, then it follows the very act of breathing should be punished. Each living person is amenable to law, judge included. Forget freedom, establish breathing permits ("breathing is not a right, it is a privilege"). More likely this policy would meet some resistance. It could bring down all legislation against "pollutants" and evil/irresponsible guys involved in the act of "polluting" (i.e. killing/robbing people). Collateral damage of the most undesirable kind. Invent another term, please.
  45. Is CO2 a pollutant?
    Got to agree with Alexandre. Somewhere along the way we have forgotten the concept of enough.
  46. Is CO2 a pollutant?
    Anything can be a pollutant, in the wrong concentration. Even if it´s a naturally occurring substance. Take any substance that´s part of a biological cycle, vary it significantly and voila! You get undesirable consequences. Double Oxygen, anyone?
  47. Working out future sea level rise from the past
    Berényi Péter, a possible mechanism for glacial termination has been described elsewhere in this site.
  48. Berényi Péter at 00:04 AM on 12 February 2010
    Working out future sea level rise from the past
    Well, 125 ky ago axial tilt was close to its low value, somewhere around 22.5°, a degree smaller than today. If we take it into account, irradiation at North Pole summer solstice could not be substantially higher than present day Antarctic peaks. Still 7% higher than current arctic values, but is it enough to melt seventy million cubic kilometer of ice, then increase ocean temperature furher? At the tropics, where the bulk of ocean warming is done, neither eccentricity nor tilt has much effect. Are we missing something?
  49. Why does CO2 lag temperature?
    jisabi, read the part of the post after fig.2, it describes the mechanism of glacial termination with several links to relevant papers. In particular i'd suggest Caillon 2003.
  50. Berényi Péter at 23:05 PM on 11 February 2010
    Working out future sea level rise from the past
    RSVP, Bern, SNRatio it turns out you are right and I am wrong. Sorry for that. I should have payed more attention, narrative with no math can be misleading. Areal velocity is "constant" indeed, as I have assumed, but only as long as orbit is not changed. With increased eccentricity, it should decrease. So. If A is area of orbital ellipse, T is orbital period, areal velocity is A/T. Let w be angular velocity, r distance to Sun. Instead of r^2w = const (1) (WRONG! in a sense) I should have written r^2w = A/T (2) For an ellipse with semimajor axis "a" and eccentricity "e" A = (1-e^2)^0.5a^2 (3) From (2) and (3) r^-2 = wT(1-e^2)^-0.5a^-2 (4) Since instananeous energy flux is proportional to r^-2, integrating (4) for an orbital cycle (from 0 to T) and dividing it by T gives average radiation power flux. P = 2Pi(1-e^2)^-0.5a^-2 (5) Solar input does depend on eccentricity after all, it is proportional to (1-e^2)^-0.5, so increases with decreasing eccentricity. For small values of e (1-e^2)^-0.5 ~ 1+e^2/2 (6) There is no first order dependence, that much is true. Present day value of e is 0.0167, 125 kyears ago it used to be somewhere around 0.04. Illinois State Museum Milankovitch Factors/Orbital Eccentricity http://www.museum.state.il.us/exhibits/ice_ages/eccentricity_graph.html If we assume "solar constant" (~1367 W/m^2) to be constant over such a timespan, it means a 226 mW additional average radiative "forcing" at TOA (Top of Atmosphere). Not much. Short term variations in solar constant are slightly larger than that. However, annual peak-to-peak irradiance variation due to eccentricity is proportional to 4e(1-e^2)^-2. It was 2.4 times more 125 ky ago than it is now. This year peak daily iradiance at the North Pole is 526.49 W/m^2 (on June 20-21) while it is 561.90 W/m^2 for South Pole (December 22). http://aom.giss.nasa.gov/srlocat.html Since at present perihelion occurs in early January, southern summer irradiation is considerably higher than its northern counterpart. With ancient eccentricity value and right phase of precession, peak daily irradiation at North Pole would be as high as 590 W/m^2 (12% higher than today). Of course axial tilt is also changing, making things a bit more complicated. Illinois State Museum Milankovitch Factors/Axial Tilt http://www.museum.state.il.us/exhibits/ice_ages/tilt_graph.html Anyway, enough to melt ice ferociously. On the other hand, polar winters must have got a lot more chilly back then, probably drier as well (just the opposite of what is observed in recent decades). I was also trying to deceive you (unintentionally, due to my usual hastiness) about the reasons behind constancy of semimajor axis. In fact, as we have seen, orbital angular momentum does change with changing eccentricity, even if there is no first order dependence. On the other hand, semimajor axis (which is inversely proportional to orbital energy and proportional to the two-third power of orbital period, irrespective of eccentricity) is fairly stable. For a different reason however than I was trying to push. It was worked out in late eighteenth century by Lagrange & Laplace. See link for details, amazing stuff. http://www.scholarpedia.org/article/Stability_of_the_solar_system

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