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All IPCC definitions taken from Climate Change 2007: The Physical Science Basis. Working Group I Contribution to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change, Annex I, Glossary, pp. 941-954. Cambridge University Press.

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Comments 124151 to 124200:

  1. Is CO2 a pollutant?
    RSVP, the '3 C increase from CO2 on Earth' is only partially correct. It is impossible to give an exact figure because many of the bands of radiation retained by different greenhouse gases overlap... so did a particular photon get retained by CO2... or water vapor... or ozone? The 9% estimate is computed by looking at average concentrations, location (e.g. CO2 can be found higher in the atmosphere than water vapor and thus accounts for more IR absorption there), circulation, and so forth. However, if we could somehow magically remove the overlapping IR bands from other greenhouse gases (while retaining all other bands they absorb) then CO2 would account for 26% of the 32C greenhouse warming... 8.32 C. That is a better comparison for Mars in terms of greenhouse potential since there are few other greenhouse gases there. Of course, Mars also has more CO2... but less atmospheric pressure. So you've got alot of conflicting variables in play here. Also, it was the greenhouse effect itself which disguised Venus for so long. All that CO2 in the atmosphere preventing heat from escaping means that the surface of Venus is very hot... but that heat doesn't escape out to space where we could observe it. The greenhouse effect keeps the heat contained and the upper layers of Venus's atmosphere actually seem quite hospitable and Earthlike. It was the probes which showed otherwise.
  2. Is CO2 a pollutant?
    RSVP at 18:39 PM on 14 February, 2010 "What fundamental science was missing at that time to have required the loss of so many space probes? " Not science, data, such as what was the atmospheric pressure at the surface, the temperature, things like that.
  3. It hasn't warmed since 1998
    VinceOZ at 17:17 PM on 14 February, 2010 Try as the Mail did to spin the interview, there's really not much there. Here's the part I found most shocking: "Discussing the interview, the BBC’s environmental analyst Roger Harrabin said he had spoken to colleagues of Professor Jones who had told him that his strengths included integrity and doggedness but not record-keeping and office tidying." Tut-tut. Lots of integrity but he can't keep his office tidy. Surely he must go. Vince, what say you to the graph in #40, here?
  4. Is CO2 a pollutant?
    CBDunkerson So where is the problem? Riccardo prompted me to "go back reading". I did. This is what I understood. On Mars, the greenhouse effect due to CO2 contributes to a 10C increase in temperature. On Earth a 3C increase. If I didnt get that right, please correct me. Now, my turn. I was saying earlier that Mars and Earth actually have "equivalence" of CO2 in their atmospheres in the sense that if you remove all other gases from that of the Earth, you would have about the same coverage of CO2 on the Earth as on Mars. In fact, as Earth is a larger planet (perhaps, and in this I am not hold my hand to any flames), there is even more CO2 volumetrically. But at any rate, these planets are at least par in some sense. Furthermore, both planets have the same rotation of around 24 hrs. Even though Mars is further from the Sun, according to you, the greenhouse effect is 3 times as high. Other posters have actually alluded to there not being enough pressure to activate the CO2 for spectral broadening etc. Perhaps the albedo is lower on Mars than the Earth, which I assume would favor more surface IR and more greenhouse heating. So, I dont think there is any problem, however, I do think it rather unfair to dismiss these questions as irrelevant, especially when a lot of the marketing behind the deleterious effects of CO2 has been based on image of the greenhouse effect on Venus. By the way, one last comment. With all that rocket science, astronomy, physics, chemistry, etc., apparently the situation on Venus came as a surprise when they actually sent probes over there. It should have been predictable. What fundamental science was missing at that time to have required the loss of so many space probes?
  5. Is CO2 a pollutant?
    Mike Air is what we breath here on Earth. "Air" by definition is a specific a mixture of gases, which by the way is changing over time as we can see from the graph.
  6. It hasn't warmed since 1998
    How does this jive with what Phil Jones is saying now that there has been no warming since 1995. Climategate U-turn as scientist at centre of row admits: There has been no global warming since 1995 http://tr.im/O7vd How can it be both?
  7. Is CO2 a pollutant?
    CORRECTION: I meant "Thank you CBDunkerson. You've got the right figures -- and my attempt was seriously out of wack...." Jesh!
  8. Is CO2 a pollutant?
    CBDunkerson wrote in 81:
    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
    Thank you CBDunkerson. You've got the wrong figures -- and my attempt was seriously out of wack. 1 minus the albedo for the absorbed, fourth power of the temperature for the watts implying fourth root of watts to get the temp... I found the following that shows the right approach to calculating what the temperature of a planet minus the greenhouse effect = the effective temperature. What is the Effective Temperature of Venus Atmoz 18 Jul 2007 http://atmoz.org/blog/2007/07/18/what-is-the-effective-temperature-of-venus/ I shoulda known better. Would have if I hadn't been in such a hurry.
  9. It's the sun
    Dan, I've seen that writeup elsewhere. Could you go through it step-by-step, being especially careful to help us understand the following things written by the author: --"The proportionality constant, 6.36E-9, was adjusted to get a fairly constant net energy from 1700 to about 1940"; Why? --"The up trend or down trend periods ascribed to the Pacific Decadal Oscillation (PDO) are taken as 32 years long for all periods." Why 32 years for all periods? --"The temperature range for the PDOs alone was taken to be 0.45 K for all of the PDOs." Why? For a PDO downtrend, the value added to the above sunspot calculation is 0.45 minus 0.45 multiplied by the fraction of the PDO time period that has taken place." Why?
  10. What the IPCC and peer-reviewed science say about Amazonian forests
    Charlie A at 13:41 PM on 14 February, 2010 Telegraph: "Yet it has now come to light that the IPCC, ignoring the evidence of its own experts, deliberately published the claim for propaganda purposes." An opinion piece, apparently, and odd that the Telegraph should consider unsubstantiated claims by the IPCC worse than what they themselves publish.
  11. What the IPCC and peer-reviewed science say about Amazonian forests
    http://www.telegraph.co.uk/comment/columnists/christopherbooker/7231386/African-crops-yield-another-catastrophe-for-the-IPCC.html is an article with lots of details on the IPCC claim of 50% reduction in rain-fed agriculture in Africa by 2020. It includes info on how the lead author had a company that accepted government money to study potential problems and came up with conclusion that there were no significant potential problems. Then that same lead author wrote the alarmist claims that don't jibe with his own company's studies.
  12. It's the sun
    A graph of sunspot count vs. time shows that some cycles are high for short periods and some are not as high but for longer periods. The relevant measure is energy which is the combination of both magnitude and time as in the time-integral of sunspot count. Subtracting the energy radiated from the planet results in the net energy retained by the planet. An appropriate scale factor relates net energy to average global temperature anomaly. Combine this with the Effective Sea Surface Temperature and the result is a model that accurately predicts average global temperature anomalies since 1895. That is 114 years…and counting. It is not necessary to include changes to the level of CO2 or any other ghg. Anyone that can use EXCEL can do this. Or, see it done already at http://climaterealists.com/attachments/database/TwentiethCenturyTemperatureCorrelationupdate.pdf which has links to the source data. (Replace all references to PDO with ESST which is short for Effective Sea Surface Temperature).
  13. Philippe Chantreau at 12:56 PM on 14 February 2010
    Is CO2 a pollutant?
    RSVP, Mercury is closer to the Sun than Venus, yet it's not as hot. Also, if I recall right, although Venus always presents the same side to the Sun, there is not that much difference between the sunny and shady side temperatures.
  14. Is CO2 a pollutant?
    RSVP: "Air on Mars?" That's interesting. I guess I know what you meant. Why should you find that "interesting" unless you knew nothing about Mars in the first place? Is there no "air" on Mars? If so, photographs from the Mars rovers showing dust storms and dust-devils on the surface are indeed mysterious. There is already plenty of information in the responses here and elsewhere on this website to show that the Mars/CO2 sceptical argument is wrong, or misleading, or irrelevant (actually a bit of each). What is interesting, is that you still want to use it.
  15. The IPCC's 2035 prediction about Himalayan glaciers
    Steve, the authors refer explicitly to the negative mass balance component averaged over one year. This surely means that on an annual basis the contribution is small and the eventual water scarcity we see now is not due to glaciers retreat. But, given that they are indeed retreating (they say 20% in 40 years), in the long run you will miss the whole seasonal melting during the arid season. And that will be a problem.
  16. Is CO2 a pollutant?
    PS That's right: just going off of the albedos and distances from the sun, Venus should be just one degree warmer than the earth -- where we omit the greenhouse effect of both planets due to their greenhouse gases.
  17. The IPCC's 2035 prediction about Himalayan glaciers
    Maybe we need more hydrologists and fewer glaciologists on the case. At the December 2009 AWG Conference in San Francisco - Jeff Kargel from the University of Arizona presented on behalf of a number of experts on the Himalayan Glacier controversy. I was struck by their conclusion that the glaciers only contribute 1.2% of the water flow in the three principal river systems. If that is accurate or close to being accurate, would it not call into question whether the complete disappearance of the glaciers would have any significant effect on the river flows? Following is the quote, and following that the link to the full presentation. Page 41 “9. As we have calculated, melting glaciers (specifically, negative mass balance components of the melt) contribute an estimated 1.2% (perhaps factor of 2 uncertain) of total runoff of three of the most important drainages, the Indus, Ganges, and Brahmaputra combined. The seasonal flow regulation influences and the negative mass balance is more important in local drainages close to the glacier sources, w[h]ere glaciers can dominate the hydrology in arid regions, but on the scale of the subcontinent, glaciers are secondary players in looming hydrologic problems, which stem more from population growth and inefficiency of water resource distribution and application.” The full presentation may be found at http://web.hwr.arizona.edu/~gleonard/2009Dec-FallAGU-Soot-PressConference-Backgrounder-Kargel.pdf
  18. Is CO2 a pollutant?
    RSVP wrote in 84:
    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?
    Here is the distance of Venus from the Sun:
    Orbital Semimajor Axis: 0.72 AU (Earth=1 AU) Venus Statistics http://www.windows.ucar.edu/tour/link=/venus/statistics.html
    The albedo of the earth:
    For example, the albedo of the Earth is 0.39 (Kaufmann) and this affects the equilibrium temperature of the Earth. Albedo of the Earth http://hyperphysics.phy-astr.gsu.edu/HBASE/phyopt/albedo.html
    The albedo of Venus due to the highly reflective sulfuric acid in its upper atmosphere:
    The bond albedo of Venus is 0.75. Albedo is a measurement of the reflectivity of an object. Albedo of Venus http://www.universetoday.com/guide-to-space/venus/albedo-of-venus/
    Put those numbers together and the temperature of Venus without a greenhouse effect would be roughly the same as earth's without a greenhouse effect: -16°C as opposed to -17°C. The actual temperature of Venus is 457°C and the actual average temperature of the earth is 14°C.
  19. Is CO2 a pollutant?
    One commenter said: //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.// It seems that you are confusing "pollutant" with "toxin". They are not the same thing, and "toxic" may or may not both apply to a pollutant.
  20. Is CO2 a pollutant?
    RSVP, distance from the sun is included in the calculation of the mean effective temperature CBDunkerson showed; just for info, planetary albedo is also included. Go on reading then, or should i say go back reading?
  21. Is CO2 a pollutant?
    dhogaza "Earlier you've been told: Due to the very low air pressure" "Air on Mars?". That's interesting. I guess I know what you meant. Why not just quantify the difference pressure makes and we can get on with it. However a poster name Gord was saying, that only CO2 at a lower temperature would absorb IR. This would be CO2 at higher altitudes which I assume would also be at a lower pressure. And, by the way, I never said CO2 isnt a greenhouse gas. All I have ever challenged is the idea that such a rarified gas in our atmosphere is modulating ice age cycles, and or acting as the main cause of a current global warming trend.
  22. 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?
  23. 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
  24. 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
  25. 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.
  26. 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.
  27. Skeptical Science now an iPhone app
    Windows Phone app too please! Would be very handy!
  28. 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.
  29. 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"
  30. 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.
  31. 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.
  32. Is CO2 a pollutant?
    Timothy Chase, great! I really love this good old papers. Thanks a lot.
  33. 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.)
  34. 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?
  35. 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'
  36. 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.
  37. 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.
  38. 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.
  39. 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.
  40. 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?
  41. 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!
  42. 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 ... ;)
  43. 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).
  44. Is CO2 a pollutant?
    should read "i think no one has ever said that CO2 is the MAIN greenhouse gas
  45. 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.
  46. 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.
  47. 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.
  48. 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.
  49. 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.
  50. 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.

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