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Comments 124101 to 124150:

  1. Is CO2 a pollutant?
    CBDunkerson "The vast difference in mean temperature is because Venus has a very thick dense atmosphere and Mars a very thin diffuse atmosphere." What about the distance from the Sun? Should I continue reading?
  2. Is CO2 a pollutant?
    Science and Skepticism, Part II of II But there are rather severe limits to what someone can be taught if they have no desire to learn, and beyond a certain point flood of requests for details and data that no one is likely to use simply becomes an instrument by which to waste people's time. As Gavin Schmidt wrote in a private letter to Ben Santer:
    The contrarians have found that there is actually no limit to what you can ask people for (raw data, intermediate steps, additional calculations, sensitivity calculations, all the code, a workable version of the code on any platform, etc) and like Som-ali pirates they have found that once someone has paid up, they can always shake them down again. Elizabeth May: An Informed Look at the East Anglia Emails 3 December 09 http://www.desmogblog.com/elizabeth-may-informed-look-east-anglia-emails
    ... and this seems very much to be the case given certain orchestrated campaigns. And it has recently been taken to any entirely new level by the Competitive Enterprise Institute:
    Here's just one part of the request: 1. of all records, documents, internal communications, and other relevant covered material created by, provided to, received, and or sent by an official or employee of NASA including but not limited to NASSA GISS, that in any way relate to the, receipt, handling, processing, or disposition of "Freedom of Information Act," or "FOIA" requests;... CEI requests a significant percent of all records produced by NASA Thursday, February 04, 2010 http://backseatdriving.blogspot.com/2010/02/cei-requests-significant-percent-of-all.html
    It is helpful to keep in mind the fact that many of the same organizations which are "encouraging" skepticism with regard to global warming are the same organizations that were encouraging skepticism with respect to the link between tobacco and health problems. I put together a list here:
    For those who are interested, here is a list in alphabetical order of 32 organizations involved in both the denial campaign surrounding tobacco and that surrounding Anthropogenic Global Warming: 1. Acton Institute http://www.sourcewatch.org/index.php?title=Acton_Institute http://www.exxonsecrets.org/html/orgfactsheet.php?id=5 2. American Legislative Exchange Council (ALEC) http://www.sourcewatch.org/index.php/American_Legislative_Exchange_Council http://www.exxonsecrets.org/html/orgfactsheet.php?id=10 ... Comment 855 of Real Climate's "Unforced Variations" http://www.realclimate.org/index.php/archives/2009/12/unforced-variations/comment-page-18/#comment-151461
    Guess what? The Competitive Enterprise Institute is on there as number 10. With respect to skepticism regarding the conclusions of established science, it is helpful to keep the following quote from an internal Brown and Williams document in mind:
    Doubt is our product, since it is the best means of competing with the “body of fact” that exists in the mind of the general public. It is also the means of establishing a controversy. Smoking and Health Proposal (1969) http://tobaccodocuments.org/landman/332506.html
  3. Is CO2 a pollutant?
    suibhne wrote in 45:
    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!
    carrot eater wrote in 46
    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.
    suibhne wrote in 78:
    Thanks for your explanation carrot eater. I will try to examine the more sophisticated model. You must admit though that people are entitled to be sceptical when they are told of; A greenhouse effect which we are then told is nothing like a greenhouse at all. An atmosphere radiating back to the Earths surface explained by using the Stephan Boltzman equation, but then saying that this was not meant to be taken seriously.
    suibhne, when you write, "You must admit though that people are entitled to be sceptical when they are told of; A greenhouse effect which we are then told is nothing like a greenhouse at all," it helps to realize that the greenhouse effect is actually a lot like the way that a greenhouse works -- in that while it permits energy to enter the system due to transparency to visible light (in the case of the greenhouse by means of transparent glass but in the case of the greenhouse effect due to the transparency of the atmosphere itself), it reduces the rate at which thermal energy is able to leave. Yes, of course there is the difference between the greenhouse that reduces moist air convection and the greenhouse effect which reduces the loss of heat due to "gasp!" invisible light. No, the earth's atmosphere doesn't have a glass roof -- but using such images (or the image of a blanket -- whether it is made of wool or one of the reflective space blankets that works primarily by reducing the loss of heat by thermal radiation) but people typically find such images and metaphors more helpful than an explanation that typically presumes a bachelor's degree or higher in physics. When you write, "You must admit though that people are entitled to be sceptical when they are told of; ... An atmosphere radiating back to the Earths surface explained by using the Stephan Boltzman equation, but then saying that this was not meant to be taken seriously," judging from carrot eater's explanation it is meant to be taken seriously -- but it is the Stephan Boltzmann law of blackbody radiation -- and this presupposes an absorptivity/emissivity of 1 (meaning that the object is completely black at all wavelengths). If you want to apply it to objects that are grey then you need to take into account how the absorptivity will be less than 1. If you want to apply it to realistic bodies that have an absorptivity that varies with wavelength then you need to take into account the fact that the absorptivity isn't a constant with respect to wavelength. The absorption and emission of radiation by a true black body as a continuem of constant absorptivity and emissivity lies at one end of "the spectra," the absorption and emission lines of certain alloys, crystals, dusts and greenhouse gases at the other end. But from one end to the other it is all thermal radiation. You want to really understand the reasons for the differences? Be prepared to take courses in thermodynamics, quantum mechanics, statistical mechanics and radiation transfer theory. You aren't really interested in going that far? Then you really don't have much reason for complaining that the science is opaque. Nevertheless...
    I think that we can all agree on open science with open data and traditional honesty where criticism is welcomed and not seen as a threat. As Mao once said "let a hundred flowers bloom, and a thousand thoughts contend"
    ... there is a great deal of science that is online. For example, the infrared imaging of the AIRS (Atmospheric InfraRed Sounder) instrument has an entire website devoted to it here: AIRS http://airs.jpl.nasa.gov ... and extensive catalogue of online images here: AIRS: Multimedia http://airs.jpl.nasa.gov/multimedia/multimedia_toc/ ... documentation, specifications, an online database of all the peer reviewed articles that have made use of its data, a selection of available articles -- all of which I have linked to here. All documentation and data is open access and free to the public -- or at least those members of the public that are willing to take the time and look for it. You have climatologists making available detailed explanations for the laymen, a number of which I linked to here specifically regarding how thermal radiation laws apply to greenhouse gases. You can even download entire climate models -- one version after another as they are developed by NASA GISS. Heck, one recent go at explaining the radiation transfer theory that underlies our understanding of the greenhouse effect by a climatologist was made less than a week ago and can be found here: Another Try MONDAY, FEBRUARY 08, 2010 http://rabett.blogspot.com/2010/02/another-try.html
  4. Is CO2 a pollutant?
    RSVP, I don't understand why you're still on this 'Mars has carbon dioxide so it should not be cold' bit. Look at effective temperatures, that is the temperature the planet would have based solely on the amount of radiation hitting it and its albedo, vs mean surface temperatures; Eff Mean Venus: 227 K 735 K Earth: 255 K 287 K Mars: 217 K 227 K So, all three planets have some amount of additional heat which has to come either from internal thermal activity (which is VERY low on Mars) or a 'greenhouse effect' in the atmosphere, which is in fact responsible for nearly all the 'extra' heat in all three of these cases. Like Mars, the atmosphere of Venus is over 95% carbon dioxide. The two planets also have very similar effective temperatures. The vast difference in mean temperature is because Venus has a very thick dense atmosphere and Mars a very thin diffuse atmosphere. Earth's atmosphere bears virtually no resemblance to that of either of these two other planets... either in density or composition. The 32 C of greenhouse warming observed here is primarily due to water vapor. If all greenhouse gases with overlapping spectra were removed than CO2 would contribute about 26% of the Earth's greenhouse effect. The usual estimate of how much it actually contributes currently is about 9%... or a little under 3 C. On Mars CO2 is responsible for virtually all of the 10 C greenhouse warming. So where is the problem? Mars is warmer than it would be without the CO2 greenhouse effect. If the atmosphere were not so thin it would have a stronger greenhouse effect (cf. Venus), but even as it is Mars experiences much more warming from CO2 than Earth does.
  5. Is CO2 a pollutant?
    RSVP:
    Mars and Earth have "equivalent" amounts of CO2
    Earlier you've been told:
    Due to the very low air pressure, so that spectral lines remain very narrow, lacking the so-called pressure (or collisional) broadening.
    Either you don't understand what is meant by collisional broadening, in which case you should go read one of the links provided above ... Or you're intentionally throwing out well-known, 60 year old, physics, pretending it doesn't exist. Which is it? The first possibility is curable.
  6. Skeptical Science now an iPhone app
    Windows Phone app too please! Would be very handy!
  7. Is CO2 a pollutant?
    RSVP at 02:08 AM on 14 February, 2010 Even letting aside Phillipe's good point regarding the whole issue of net albedo effects of solar capture systems, we don't really need to worry about the little ways we can redirect or reject energy arriving from the sun at various solar capture systems. Any changes we can make in that department are a microscopic iota compared to others we're already accidentally promoting. Here's an illustration. Considering the loss of Arctic sea ice since circa 1980, on a typical summer day in the present the Arctic ocean is absorbing more additional energy than the entire world electrical generating capacity, by a large amount. Total global electrical demand is about 16TW. Back of the envelope calculation by a favorite skeptic of mine shows -at least- 40TW of additional energy being sucked up by the Arctic ocean on a summer day as a result of ice loss. What that tells us is that the amount of energy sloshing around here is so gigantic that any effects we may cause by tweaking a few km2 of albedo with capture systems are vanishingly small. This confusion probably has a little to do with the white roof/pavement schemes being promoted for reducing energy demand. Those are aimed at cutting air conditioning costs so as to reduce fossil fuel consumption thus reducing C02 pollution. They're not about increasing the total albedo of the planet.
  8. Is CO2 a pollutant?
    Thanks for your explanation carrot eater. I will try to examine the more sophisticated model. You must admit though that people are entitled to be sceptical when they are told of; A greenhouse effect which we are then told is nothing like a greenhouse at all. An atmosphere radiating back to the Earths surface explained by using the Stephan Boltzman equation, but then saying that this was not meant to be taken seriously. I think that we can all agree on open science with open data and traditional honesty where criticism is welcomed and not seen as a threat. As Mao once said "let a hundred flowers bloom, and a thousand thoughts contend"
  9. Is CO2 a pollutant?
    PS to 74 If anyone is wondering, yes, the address on the Plass paper... Strong, J. & Plass, G. N. (November 1950) The Effect of Pressure Broadening of Spectral Lines on Atmospheric Temperature. Astrophysical Journal, vol. 112, No. 3, p.365-79 http://articles.adsabs.harvard.edu//full/1950ApJ...112..365S/0000365.000.html ... actually has those dots in it. There is a pdf available as well. Incidentally, one of the points that I find interesting is that while they understood that quantized states of molecular excitation are responsible for the absorption bands and lines -- they mention a pure rotational bands (as opposed to rovibrational) of water vapor in "the region beyond 17μ on page 368 -- they were relying upon a fair amount of in the field observations as well as laboratory studies which were being carried out at the same time. For example, they state:
    Data on Absorption in the Infrared in the Stratosphere We are fortunate in having certain high-altitude measurements of the transmission characteristics of the upper atmosphere in the infrared which shows the bands that are important for our considerations. Figure 2 gives a curve representing the transmission of the atmosphere from 8 to 26 μ above 33,000 feet altitude... ibid., pg 368
    ... and:
    50 μ H2O Band Experimental studies of the absorption of this band in the region of 10-30 μ, which will be adepquate for the purposes of this calculation, are just now being carried out. It is uncertain whether the main absorption in this region is from lines or from the wings of very strong lines at 50 μ... ibid. pg375.
    The lack of convection in the stratosphere is explained as a consequence of pressure broadening (or lack thereof) and high rate thermal emission, mention of how absorption takes place according to the square root rather than the logarithm at lower pressures. I would assume that the high altitude measurements were being performed by the military at the time for the development of fighter infrared vision or something along those lines. If anyone knows... * One other point that may be of interest. In: Pressure broadening Thursday, July 05, 2007 http://rabett.blogspot.com/2007/07/pressure-broadening-eli-has-been-happy.html ... Eli gives a link to the Spectral Calc. It is no longer there at that address. The new address is: Spectral Calc http://www.spectralcalc.com/calc/spectralcalc.php There if you are so inclined you can calculate their own absorption spectra if they are so inclined. The graphs that get produced are below the fold. Anyway, hard to imagine people arguing with physics and data which is more than half a century old. Then again, some of the science behind the greenhouse effect is more than a century old, and they will argue with that as well, and I was on the evolution/creationism front for several years... I guess I really shouldn't find it that hard to believe.
  10. Is CO2 a pollutant?
    Philippe Chantreau What is my point? Mars and Earth have "equivalent" amounts of CO2, (plus Mars also an almost 24 hr rotation), the difference being that on Mars the CO2 is not diluted as on Earth. These conditions appear to lend themselves to a useful comparison. Aside from this potential, given that at average temperature of the planet is around -43C, (and gets to around -120C) on the outset, it doesnt appear that the CO2 is doing a whole lot of warming on its own other than buffering temperatures any gas would.
  11. Is CO2 a pollutant?
    Timothy Chase, great! I really love this good old papers. Thanks a lot.
  12. Is CO2 a pollutant?
    jenikhollan wrote in 56:
    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.
    I just bumped into a classic from 1950, almost 60 years ago: Strong, J. & Plass, G. N. (November 1950) The Effect of Pressure Broadening of Spectral Lines on Atmospheric Temperature. Astrophysical Journal, vol. 112, No. 3, p.365-79 http://articles.adsabs.harvard.edu//full/1950ApJ...112..365S/0000365.000.html Of course if others are interested in something more recent: Pressure broadening Thursday, July 05, 2007 http://rabett.blogspot.com/2007/07/pressure-broadening-eli-has-been-happy.html High Pressure Limit. . . . Sunday, July 08, 2007 http://rabett.blogspot.com/2007/07/high-pressure-limit.html Its great what you can find online nowadays. For example, I have found several of the classics in pdf on Spiegelman's monster by Sol Spiegelman and Manfred Eigen from the 1960s-70s. (One of my interests is the RNA world and the role of retroelements in evolution.)
  13. Philippe Chantreau at 03:49 AM on 14 February 2010
    Is CO2 a pollutant?
    RSVP, your reference to Mars' atmosphere is obtuse. What are you trying to say? Mars' surface is warmer than it would otherwise be without its CO2 atmosphere. Earth benefits from the GH effect of CO2, water vapor and other gases. Obviously, if it had only CO2, it would be a lot colder, yet still warmer than space, so what exactly is your point? On this: "What would the world be like if everyone setup solar panels?". Solar panels actually trap solar radition that would otherwise reflect back into space my friend." Interesting idea. By all means, elaborate. That radiation actually would be relected only if it strikes a high albedo surface, which makes up little of the total surface and virtually none of the suitable areas for solar panel installation. So, in fact, it would heat up the surface and be re-radiated upward as IR. If instead that energy is captured, transformed and converted into various kinds of work, does it somehow add to the total energy? Will it somehow inject more heat into the system? Where will the "trapped" energy end up going, eventually?
  14. Medieval Warm Period was warmer
    "The Medieval Warm Period was warmer than current conditions. This means recent warming is not unusual and hence must be natural, not man-made." The argument is also logically invalid, even if the premise were true. Otherwise the following argument of the same form would be correct: 'The Black Death in the middle ages is estimated to have killed more of Europe's population than World War 2. This means that deaths during World War 2 were not unusual, and hence must be due to natural causes, not man-made'
  15. Is CO2 a pollutant?
    SNRatio Replacing old technologies with new technologies on a global scale can not happen in a vacuum. To name just a few issues: 1) Actual benefits of new technologies (to what extent can they allay global warming or other negatives to the environment) 2) Time for transition. Is the rate possible to make a difference while fossil fuels are running out anyway. In other words, what is the optimal pace for minimizing global warming. 3) Which technologies should we actually be choosing? 4) ETC. Assessing these questions lends itself very much to science (or engineering if you will). I never advocated any measures, in fact, just the opposite. On the other hand, you have already prescribed howt others might follow your lead. A very scientific question would be, "What would the world be like if everyone setup solar panels?". Solar panels actually trap solar radition that would otherwise reflect back into space my friend.
  16. Is CO2 a pollutant?
    RSVP, 70: "Obviously, you could start however by reducing tourism for example. Cut out frivolities such as the movie industry. Motocross and car racing. What else? You dont see much talk about this here. All you see are blank statements about the need to reduce CO2. " This is not a forum for discussion of social and economical issues, and, luckily, what it takes to develop in a sustainable way is no longer a scientific or technological problem - so that's really not in the scope of what is important to discuss here. Basically, we have no lack of resources, not really of knowledge either, what we have is a lack of skills and will. And it's not about not using energy, it's about the forms and the smartness. Therefore, please stop talking about bans on motocross or whatever. It's complete nonsense. What you _could_ talk about, is incentives to electrify the transport sector faster. Like some money to make me complement my solar collectors with a few solar panels. So I could, for instance charge my car from them. The collectors, flat plate and vacuum tubes in series, work like magic. Right now: -5 outside, the sun sets in a few minutes, and it's still 10 degC in and 50 degC out from the collectors. (Latitude 60.20 N) Pre-heats domestic water, heats the house, regenerates the soil collector for the heat pump. Please don't talk about this being so difficult. Either you haven't really tried, or you lack skills.
  17. Is CO2 a pollutant?
    SNRatio "We just don't know how big it will turn out to be " Making that determination is one excercise. The other would be a series of projections in seeing how mankind could fare by actually following a prescription for reducing CO2 emissions into the near future. Has anyone done this, with detailed consideration to all its consequences? There was this book called The Limits to Growth. It only looks at the negatives of growth but provides no recipes nor describes the actual consequences of pulling back on fossil fuel consumption. We are already seeing problems with a floundering world economy without even starting. Obviously, you could start however by reducing tourism for example. Cut out frivolities such as the movie industry. Motocross and car racing. What else? You dont see much talk about this here. All you see are blank statements about the need to reduce CO2.
  18. Is CO2 a pollutant?
    Bob Armstrong: "While the effect of a little more CO2 on the spectrum and therefore mean temperature of the planet is minor ( see http://cosy.com/Science/LogCO2effect.jpg ) , its enhancement of plant growth is profound : http://cosy.com/Science/CO2-pineGrowth100120half.jpg ." OK. "a little more" CO2 would be fine with most, I think. What we are discussing, is how to avoid a doubling, we are already about 40% on the way. If you are saying that a 40% increase in CO2 has minor impact on the mean temperature, and think that is backed by physics, you should do a careful checking of the physics. Because it does not seem to be backed by observations. Assertions of CO2 saturation, almost complete overlapping with H2O etc seem to be, in general, false. On the contrary, observations so far indicate a CO2 sensitivity far above the basic 1 degC/doubling, i.e. a considerable positive feedback. We just don't know how big it will turn out to be - far too little observations on the radiation balance of Earth for that.
  19. Is CO2 a pollutant?
    Mike, the atmosphere on Mars is nearly pure CO2. As I explained in my first post in this article, I calculated the height of what a pure CO2 atmosphere would be on Earth if all other gases were removed. This would leave a CO2 cover on the entire Earth with between 7 and 30 meters, much as exists on Mars. In any case, greenhouse effects of water vapors would be apples, and that CO2 oranges. Are you implying that CO2 acts as a greenhouse catalyst for water vapor?
  20. Is CO2 a pollutant?
    I do not believe I have just read the "Mars atmosphere" argument again. Aside from the massive difference in solar flux it experiences due its comparative distance from the sun, it also lacks much of an atmosphere at all. Certainly it doesn't have any significant amount of water vapour - the other important greenhouse gas on Earth. So the feedback effects are just not even in the same ballpark. It doesn't even qualify as an "apples vs oranges". It's comparing apples with.....durian!
  21. There's no empirical evidence
    40 Shades of Green, the strength of the AGW theory and the reason why no one has succeded to falsify it and and make a new one is that there many lines of evidence pointing to the same conclusions. You do not like models? Take the CO2 forcing and a climate sensitivity from observations and you'll still end up there. Don't like surface stations? Take satellites, same story. And so on ... I don't need to continue, John already did the dirty job ... ;)
  22. Is CO2 a pollutant?
    What I perhaps left out in #63... I mean to distinguish heating of the atmosphere through 1) convection from surface, 2) IR emanating from surface that is picked up by atmosphere Only #2 should be considered greenhouse heat. The result of #2 is: a) slightly warmer atmosphere, b)a slightly higher surface temperature (due to slightly less convection, which in turn (by definition) can only be attributed to #2). I was convinced by poster Gord, that an item c) is not real (so I leave this out here). It has to do with IR emanating from the atmosphere and warming the surface (those arrows that point down out of the sky in greenhouse diagrams).
  23. Is CO2 a pollutant?
    should read "i think no one has ever said that CO2 is the MAIN greenhouse gas
  24. Is CO2 a pollutant?
    RSVP, i think no one has ever said that CO2 is the greenhouse gas. You are arbitrarly assigning this role to it. Indeed, CO2 is responsible of roughly 30% of the whole effect. Even considering AGW, we all know that CO2 alone would not lead us to 3 °C of warming, may half of it or even less. So it is the interaction between the various part of the whole earth climate system that matters. On the contrary, Mars has an almost "dead" climate system. This is why your parallel between the two is wrond, not becaus it "is a bad comparison because it tends to show AGW is not related primarily to "anthropogenic" CO2", which it does not show. "CO2 on the Earth is thousands of times more diffuse, which means IR surface emissions have even less chances of being affected by it." You should look a little bit closer at how the radiative balance in the real atmosphere works. Even the zeroth order aproximation would tell you that as far as the absorbtion is concerned what matters is the integral over the whole atmosphere. On this respect, it does not matters if it is diffuse or not.
  25. Is CO2 a pollutant?
    MattJ said "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. " When you say "greenhouse effect" are you talking about the rewarming of the surface of Mars due to the CO2(i.e. the slowing down of loss of heat), or simply the heat that the atmosphere there acquires? These would be separate I assume. If for instance, Mars had an atmosphere of pure Nitrogen, and the average temperature was -39.5C, the only "greenhouse effect" would associated with the 0.5 C temperature difference. This is what I am talking about when I refer to "primary" contributor. Maybe the definition gets used too loosely in these discussions.
  26. Skeptical Science housekeeping: iPhone app, comments and translations
    Tony O, the 'Recent Comments' section at the bottom of the profile page looks like it may just be the most recent comment posted to any discussion on the site. Thus, not intended to have anything to do with you. It IS a bit odd that the only things on 'our' profile pages are an esentially random comment, a link to add a new skeptic article, and a link to update the profile... so absolutely no information about the user on their profile page. Maybe the username and address could be displayed, or the 'profile' page somehow merged with the 'update profile' page.
  27. There's no empirical evidence
    40 Shades of Green at 12:00 PM on 13 February, 2010 It sounds as if you've been badly misinformed. In order to get a basic understanding of this topic, start with reading Spencer Weart's work, here: The Discovery of Global Warming Next, before accepting and counting on what you read on Anthony Watts' site, take into advisement that Mr. Watts was unable to discern the difference between temperature trends versus absolute temperature measurements. He thus was misled into making many embarrassingly wrong statements regarding the temperature record in the United States, as well as launching a large volunteer effort in an attempt to prove his fallacy. Output of his project actually helped to cement the simple wrongness of his incorrect hypothesis. You should also take a closer look at the ARGO buoy data, from an authoritative source. Ocean heat content has actually increased since the inception of the ARGO program. It's rather inexplicable that anybody should think otherwise at this late date. Having taken all that on board, it would be good to rethink your conclusions.
  28. Is CO2 a pollutant?
    Ned wrote in 60:
    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
    Thank you. I will check them out. There are usually some pretty good links -- and the writing usually isn't that bad, either.
  29. Is CO2 a pollutant?
    I'm surprised my comment which was numbered 8430 was removed . The second half presents the relevant data : While the effect of a little more CO2 on the spectrum and therefore mean temperature of the planet is minor ( see http://cosy.com/Science/LogCO2effect.jpg ) , its enhancement of plant growth is profound : http://cosy.com/Science/CO2-pineGrowth100120half.jpg . Interested people will have to go to my forum to see the first half which is effectively they conclusion and consequences .
    Response: Note that this version of your comment, which has been stripped of the political rhetoric, has not been deleted.
  30. 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.
  31. 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.
  32. 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.
  33. 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.
  34. 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:

  35. 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.
  36. 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.
  37. 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
  38. 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.
  39. 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.
  40. 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.
  41. 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
  42. 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.
  43. 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.
  44. 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?
  45. 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.
  46. 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?
  47. 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.
  48. 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.
  49. 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!
  50. 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.

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