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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 125551 to 125600:

  1. What ended the Little Ice Age?
    This is a good article. Firstly, it's hard to get much about the contributions from the sun out of most people advocating AGW. The period from 1880s to 1940s shows the sun has an important effect. From about the 1940s-1960s, those advocating the continuance of relatively strong warming effects from the sun have to resort to scrambling for 'unknowns' such as cosmic rays, long heat lag effects, and who knows what else (magnetic fields, UV etc etc), but they are still a possibility. One has to remember that the sun is not just a simple and unchanging ball of fire; it is still quite possible that solar effects, as yet not understood, contribute strongly to warming since the mid 20th century, although admittedly, there isnt any known mechanisms to account for this-at least not yet. Without these 'unknown' solar possibilities, including long heat lag effects, the skeptics arguments for warming since the 1950s are relatively weak. PS. Also, I think the papers advocating increased build up of heat in the oceans and various disequilibrium effects etc, are flawed because they generally rely on modelled forcings relating to greenhouse gases; like the hockeystick, these papers, the data and their conclusions are somewhat manipulated and unreliable. I dont trust them very much. A good example is Hansen 2005 (elsewhere on this site), where his 'warming in the pipeline' calculations are based on modelled effects and assumptions from greenhouse gases. Good article above though.
  2. Is the airborne fraction of anthropogenic CO2 emissions increasing?
    Riccardo - not to disrespect any scientist - but do you believe there are enough data points throughout the entire shell of the atmosphere to accurately model CO2? In my estimation there is not a computer model in the world that can predict future CO2 and future global temperatures. It is difficult to model a 2 dimensional system such as a river for pollutants with any degree of accuracy. Now, we are being told that the world can be modeled for a sneaky CO2 molecule. Complicating matters infinitely is the fact that CO2 is part of the carbon-based life-cycle on our planet. I can only guess how many assumptions need to be made in such a model - which starts out with bare-boned CO2 data to begin with. I think its an impossible task - and irresponsible of scientists to imply to the public that they know firmly anything at all about the climate other than what the weather channel can give us. BTW - I have extensive computer modeling experience and a graduate degree in environmental engineering and know that models of natural systems are nothing more than curiosities. I don't like to see others touting these models as truth - cause they're not. I would listen to a model of global CO2 that had 100 years of data tied with accurate temperature data and ground CO2 data at grid points of 5 miles including the oceans and air columns. Until that data arrives I'll be skeptical. No "tree rings" for me.
  3. Could CFCs be causing global warming?
    Riccardo, Agreed. Correlation is great for initiating an investigation, but not for demonstrating a cause and effect. The increase in Scotch whiskey consumption in Pennsylvania increased by 3.2% in 2009. The increase in teachers pay in Pennsylvania increased by 3.2% in 2009. Ergo..... Maybe a bad example; that probably is a cause and effect.
  4. Is the airborne fraction of anthropogenic CO2 emissions increasing?
    ralphiegm, "Riccardo - are you saying that Antarctica is releasing CO2 ?" Actually the opposite. CO2 is NOT emitted in Antarctica but it's there at roughly the same concentration as anywhere else because it is well mixed. And it is well mixed because it is long lived and it can not condense into liquid nor evaporate from an existing liquid. The very opposite is true for water vapour which infact is NOT (at all) an indicator of the mixing of the atmosphere. Hence your supposed "proof" (sic) of incomplete mixing is faulty. "A true scientist would be worried about such problems." Please do not suppose that all the scientists are not true scientist just because they do not agree with you. And do not think you can teach people how to do their job while you're nowhere near the field.
  5. Is the airborne fraction of anthropogenic CO2 emissions increasing?
    Jim - I think a particulate can be an indicator of mixing in the atmosphere. Why not? My point being only that the data appears to be so limited on the CO2 in the atmosphere since there are only 200 or so data sets. I think I have shown that there is proof of incomplete mixing in the atmosphere by merely viewing the variability of clouds. My observation is as (in)accurate an assessment as "tree rings" are for long term temperature models. Further, the NASA global CO2 map shows no correlation between industrial land uses and the highest CO2 values. A true scientist would be worried about such problems.
  6. Is the airborne fraction of anthropogenic CO2 emissions increasing?
    "are you saying that Antarctica is releasing CO2 ?" Easy enough to actually look up. Hmmmm, Mount Erebus, erupted in 2008 & 2009. Date of cited ARIS CO2 plot, July, 2008. I'm just sayin.
  7. It's freaking cold!
    What do you think about Anthony Watts' attempted debunking of the Meehl 2009 report by complaining that it "cherry picked" temp records from 1950 on when 1930 had more record lows than highs? See http://wattsupwiththat.com/2009/11/16/why-ncars-meehl-paper-on-highlow-temperature-records-is-bunk/ It looks to me like Watts is really looking at numbers of record highs and lows and not ratios of highs to lows, but nonetheless it would be nice to see a debunking of the debunking. Overall, it would be even nicer to see a global report on record highs vs record lows to see if the trend Meehl et. al. found in the U.S. is really a global phenomena.
  8. What ended the Little Ice Age?
    DeNihilist, if a small sun variation can induced detectable increases in temperature it can only mean that climate sensitivity is much larger than expected or that some fast feedback specifically related to the sun forcing must be acting. This would be good news for the "it's cosmic rays" belivers. Unfortunately (for them) we know it can not be it. Problems also arise when considering the big picture of the climate of the past, it would be hard to explain the temperature difference between glacial and interglacial with such a huge sensitivity (plus the slow fedbacks in action).
  9. Is the airborne fraction of anthropogenic CO2 emissions increasing?
    Ralph, clouds are not an indicator of mixing, they are an indicator of 1) a temperature low enough that water vapour will condense into water droplets and 2) the presence of sufficient nucleation particles for them to condense onto. "Assume I said pollen, or dust..." Then you would be talking about solids, not gases. CO2 is a gas.
  10. Is the airborne fraction of anthropogenic CO2 emissions increasing?
    RE: ralphiegm Clouds are made up of frozen droplets, that is each frozen droplet contains millions of water atoms bonded together. Water molecules have a strong dipole moment and so so will form crystals quite readily if given the right conditions, and if I quote wikipedia for water... "Oxygen attracts electrons much more strongly than hydrogen, resulting in a net positive charge on the hydrogen atoms, and a net negative charge on the oxygen atom. The presence of a charge on each of these atoms gives each water molecule a net dipole moment. Electrical attraction between water molecules due to this dipole pulls individual molecules closer together, making it more difficult to separate the molecules and therefore raising the boiling point. This attraction is known as hydrogen bonding." CO2 is very different when in the atmosphere not only is in the gas phase (so you won’t get them bonding together like water) but it has a zero dipole moment . Thus you would expect that its behavior to be different from water in the atmosphere given it being in a different phase and having a distinctly different electronic structure. The 'hard sphere model' which I think you’re trying to compare it to (ping pong balls, pollen or even billiard balls) is a good model for other more simpler molecules and systems but it will not adequately represent these molecules in the atmosphere.
  11. Is the airborne fraction of anthropogenic CO2 emissions increasing?
    ralphiegm, your reasoning is correct if two conditions are met: 1) no phase transitions (gas/liquid, liquid/solid etc.) 2) equally long lifetime and source/sink stength of the molecules in the atmosphere. Neither is met by water vapour; it condenses to form liquid droplets or solid crystals (clouds) and viceversa it can readly evaporate from the oceans or land; it's lifetime is quite short. If you accept that CO2 lifetime is long and that no liquid or solid CO2 can exisist in our real atmosphere, even common sense will indicate that it may be considered well mixed. One final remark, i'm sure you know that a lot of volatile substances has been found trapped in the antarctic ice even if they have been originated somewhere else in the planet. The same happens to CO2.
  12. Is the airborne fraction of anthropogenic CO2 emissions increasing?
    Ian - you avoid the point I am making, the ping pong balls are imaginary, an example - just something to indicate mixing. Assume I said pollen, or dust, or chlorine. If the atmosphere was completely mixed - there would be these indicators in equal concentrations everywhere. Clouds are an indicator of mixing in the atmosphere - and they show that the atmosphere is not well mixed.
  13. Could CFCs be causing global warming?
    Doug Cannon, the water vapour cause/effect relation is not with CO2 but with temperature and is well established from both basic physics and observations in the atmosphere. The magnitude of the effects is "just" radiation physics, not much uncertainty on this. On the contrary, clouds are still a weak point both for basic physics and observations. And this was the topic of Spencer talk at the AGU meeting. What i found most interesting is the (tentative) use of correlation to separate the "internal radiative forcing" (in Spencer words) from the feedback; but then it's necesessary to discriminate between the different types of clouds which has not been done. Anyway, good science and new ideas from anyone are always welcome.
  14. Is the airborne fraction of anthropogenic CO2 emissions increasing?
    ralphiegm said:
    the clouds could be made of helium filled ping-pong balls for my argument. If the atmosphere was completely mixed we would be seeing these ping pong balls (clouds) everywhere in the sky.
    Have you ever filled a balloon with helium and let it go? Please tell me what your engineering experience tells you. Will it fall to the ground, remain at head height or quickly rise into the sky and disappear from sight in the heavens? Any engineer worthy of the name should understand simple density.
  15. Is the airborne fraction of anthropogenic CO2 emissions increasing?
    Jim - I am only using clouds as an "indicator" of mixing - the clouds could be made of helium filled ping-pong balls for my argument. If the atmosphere was completely mixed we would be seeing these ping pong balls (clouds) everywhere in the sky with a 3% or less variance (as is reported for CO2). But we don't see clouds everywhere - we can agree to that I hope. So why would we expect CO2 to be so evenly spread out through the atmosphere? Something is amiss and I suspect it is the actual CO2 data which comes from so few actual CO2 samples, relatively speaking. In my estimation there are undiscovered CO2 cool spots laying about which may balance out reported rises in CO2.
  16. Could CFCs be causing global warming?
    Riccardo, Yes, I'm aware of the water vapor/temperature relationship. I'm also familiar with Dessler's work to which you referred. By "unproven" I refer to the direct cause and effect relationship to CO2 in the models and it's magnitude. I found it interesting that Dessler invited the Spencer paper at the AGU conference in SF. It's good that those on both sides of the issue agree it's an important one to debate.
  17. Is the airborne fraction of anthropogenic CO2 emissions increasing?
    ralphiegm wrote @18: I think the idea that CO2 is diffused evenly througout the atmosphere is bogus. If that were true then all molecules of any type would be equally distributed - including clouds. Ralph, as an engineer are you not familiar with the concept that temperature falls with altitude, thus limiting the amount of water vapour in the atmosphere as altitude increases? (Look up terms: lapse rate, moist adiabat, relative and absolute humidity, condensation) There is no such limitation on the mixing of CO2.
  18. Is the airborne fraction of anthropogenic CO2 emissions increasing?
    I assume clouds are water vapor - dense "clouds" of water "molecules". If the atmosphere was completely mixed then "clouds" would appear uniformly in all the sky. And the high concentration of CO2 over the Antarctica is really puzzling - it makes me skeptical when I see data that does not fit one's common sense. I thought all this CO2 was supposed to be coming from blast factories - I doubt penguins have mastered that technology.
  19. Could CFCs be causing global warming?
    Doug Cannon, it's hardly unproven that water vapour content depends on temperature. But you know, scientist always like to go back and check in any different situation. Here you'll find some general discussion on water vapour feedback while here you can find a list of scientific papers.
  20. What ended the Little Ice Age?
    As you are probably already aware, Prof. Svalgaard disputes that the sun actually has "warmed" up in the last few hundred years. http://www.leif.org/research/Seminar-SPRG-2008.pdf Not sure what this means to the early warming from the LIA, but something?
  21. Could CFCs be causing global warming?
    I agree with the concept of looking to the physics of CFC radiation forcing and that concept certainly supports the idea that Lu's conclusion is at least premature if not totally wrong. However, we also have to realize that the physics of CO2 radiation forcing doesn't support the results in the IPCC's models either. The majority of the forcing is due to a presumed, but unproven, amplification from water vapor/clouds. It seems the issue of these secondary effects of CO2 lie at the heart of IPCC model credibility. Other than Spencer's latest, I don't see recent evidence of anyone really getting to the meat of this issue.
  22. It's a 1500 year cycle
    Anyone interested in how a cyclical signal should be detected may want to read this short and nice explanation. And those who think that a natural cycle is superimposed on a linear trend may want to read this.
  23. Is the airborne fraction of anthropogenic CO2 emissions increasing?
    Ralph, it is not necessary for satellite measurements to be calibrated against a huge number of ground stations, for the same reason that thermometers to stick under human tongues do not need to be calibrated against a huge number of human tongues. The size and type of sample needed for calibration of any instrument is properly determined by combination of observation with statistics about those observations. That's what's done with satellite measurements. An engineer should know that.
  24. Is the airborne fraction of anthropogenic CO2 emissions increasing?
    As for clouds - I think the clouds indicate the LACK of uniformity of density in the atmosphere since they show visually how different the atmosphere can be - regardless of whether you consider water a molecule or not (it is)
    Well, Ralph, a glass of water is not a molecule. A raindrop is not a molecule. The droplets of water or bits of ice that make up a cloud are not molecules. That's just fact, Ralph. As far as the number of sensors needed to accurately sample CO2 in the atmosphere, you flat-out don't know what you're talking about in this case, either.
  25. Is the airborne fraction of anthropogenic CO2 emissions increasing?
    Bern - I don't think a satellite actually measures CO2 and certainly not throughout the column. It is more that they measure something else then calibrate those readings with ground station CO2 readings. So if the ground stations are limited so will the satellite data be limited. And the NASA map indicates only some final averaging of data - the highest CO2 values over Antarctica, Peru and Morocco me skeptical. As an Engineer I would like to see widespread, actual measurements throughout the air column around the globe before I make a judgement about the state of CO2. Satellites are cute - but I am not convinced that they are providing sufficient data to base climate models.
  26. Is the airborne fraction of anthropogenic CO2 emissions increasing?
    ralphiegm @ 27: no, we don't need millions of data sensors to get a handle on the total weight of CO2 in the atmosphere. We need millions of measurements by a sensor that moves around and covers the entire globe. Like a satellite in a polar orbit. That's how that NASA map you linked was produced. AIRS returns more than three million measurements per day, according to http://airs.jpl.nasa.gov/story_archive/Measuring_CO2_from_Space/Measurement_to_Science/ There's also a comment on that page: "...carbon dioxide concentrations turn out to vary by two to four parts per million. 'Before AIRS everyone thought carbon dioxide was well mixed above the boundary layer. We found that it is not.' It can vary by nearly a percent." So to you & I, CO2 is pretty evenly distributed. To scientists, a difference of a percent is quite significant - thus the choice of a scale for the graph that *highlights* that small variation. I thought it was interesting to note the comment further down about the coal-fired power plants on the Australian east coast being one of two major CO2 sources in the southern hemisphere, the other being a coal-to-liquids plant in South Africa that is the world's biggest single source of CO2.
  27. Was there a Medieval Warm Period?
    The Wikipedia item gives a link to a pdf of the Science article: http://www.meteo.psu.edu/~mann/shared/articles/MannetalScience09.pdf . The Supplementary Information can be obtained from the Science website for those who want to read the full details and methodology.
    Response: Thanks for the link to the full PDF of the paper - I've updated the link in this blog post as well as in the page addressing the skeptic argument: "Medieval Warm Period was warmer".
  28. What ended the Little Ice Age?
    re From Peru: if there's one thing I've learned in my reading on climate, it's that responses to changes in forcing are very non-uniform across the globe. Ocean currents, in particular, can result in some counter-intuitive results (like some areas actually cooling when everywhere else heats up). Your comment re Black Carbon, though, is interesting (as it's toward the end of the LIA when fossil fuel burning really took off, so it could be a factor). I'm not sure if John has already addressed this anywhere, but I did note that the graphs above start at 1890, though warming began around 1850. It does still help to reinforce the notion of sensitivity to forcing, though.
  29. What ended the Little Ice Age?
    Here something is missing: the 1910s-1940s warming is evident only in the Northern Hemisphere and there the pattern is strongest over the Artic. If the forcing is global, like Volcano+Solar, the pattern should be evident in both Hemispheres. This is not the case, so something else might have done it. I guess that the forcing in question is Antropogenic Aerosols. Important to note that the Meehl 2004 paper ignores Black Carbon forcing. This is an important flaw, as BC is now recognized as the second strongest warming forcing, only superated by CO2.
  30. Is the airborne fraction of anthropogenic CO2 emissions increasing?
    I'll certainly take your advice but I will see if there is any one that agrees with my assessment.
  31. Polar bear numbers are increasing
    UNPRECEDENTED LOSS OF SEA ICE RENEW CONCERNS FOR SURVIVAL OF THE WORLD'S POLAR BEARS July6,2009(Copenhagen,Denmark) At the 15th meeting of the IUCN Polar Bear Specialist Group...renewed the conclusions from previous meetings that the greatest challenge to the conservation of polar bears is ecological change in the Arctic, resulting from global warming. "The Western Hudson Bay subpopulation has been on the declilne for almost two decades...the body condition in polar bears is linked to the availibility of sea ice and time of spring break-up; and that when sea ice is available for less time, body condition declines ultimately affecting reproduction in adult female bears..."... ...Reviewing the latest information available, the PBSG concluded that one of 19 subpopulations is currently increasing, three are stable and eight are declining. For the remaining seven subpopulations, available data were insufficielnt to provide an assesment of current trend. The subpopulation increasing is located in Canada's high Arctic, an area that has not seen as much loss of sea ice as others, suppporting the Group's analysis of the critical relationship between the health of polar bears and the amount of sea ice... The IUCN (International Union for the Conservation of Nature and Natural Resouces) Polar Bear Specialist Group...each of the five circumpolar nations that signed the International Agreement for the Conservation of Polar Bears of 1973 - Canada, USA, Greenland(Denmark), Finland and Russia... polarbearsinternational.org Press Release ...(Nov3,2009): For the first time, researchers are studying...the summering ecology of polar bears of the southern Beaufort Sea who choose to migrate north to the sea ice of the polar basin when the winter ice pack melts, rather than return to the shores of Alaska... ...ice breaker expedition... ..."Polar bears need appropriate ice to hunt and survive. Young, thin ice can break up or disappear in a storm and older ice can actually be too thick for the bears to hunt seals..."... Polar Bears International
  32. Is the airborne fraction of anthropogenic CO2 emissions increasing?
    But Ralph, you're just wrong. Factually wrong. Empirically wrong. Seriously wrong. Go read Pierrehumbert's book. It's free. It's online so it's easy to search for key words.
  33. Is the airborne fraction of anthropogenic CO2 emissions increasing?
    I look at it this way - the earth surface area is about 200 million square miles. That means each CO2 sensor must account for about the equivalent of one million square miles (I think there are only 200-300 long term datasets). So, this is just one dataset for all of Alaska and California and Texas combined (almost). As for clouds - I think the clouds indicate the LACK of uniformity of density in the atmosphere since they show visually how different the atmosphere can be - regardless of whether you consider water a molecule or not (it is). All I am saying is we would need millions of data sensors to get a handle on the total weight of CO2 in the atmosphere and the data we have is just too weak right now.
  34. CO2 measurements are suspect
    Theo, a "single regime of measurement in the atmosphere (all the way up)" is not needed. Measurements from spacecraft are calibrated against measurements from aircraft and ground stations. Routinely. And different methods of measuring even at ground stations are calibrated against each other. Ditto for aircraft measurements. New spacecraft often are launched while the spacecraft they are replacing are still in service, so that the new spacecraft's measurements can be calibrated against the old spacecraft's measurements. You don't read about such things in the newspaper or even on blogs, because it's part of the mundane, routine, standard, detail of empirical science.
  35. CO2 measurements are suspect
    Theo, see my 13:49 PM on 4 January comment on the Is the airborne fraction of anthropogenic CO2 emissions increasing? thread. See also dhogaza's comments in that thread. "Well mixed" is not an assumption, it is a longstanding observation.
  36. Is the airborne fraction of anthropogenic CO2 emissions increasing?
    Ralph, you are incorrect that there are "no data on CO2 close to the Earth." Just no data at that level of the atmosphere from AIRS. There are lots of data at that level from ground stations and aircraft, all over the world. The fact that CO2 is well mixed is not an assumption, nor a theoretical prediction. It is an observed fact dating back to at least the U.S. military's measurements in the 1940s. The number of observing stations, and their distribution, have been settled on as a satisfactory sampling, based on those empirical observations. Read dhogaza's comments in this thread; the variation in the mid-troposphere is tiny--less than half of the already-tiny 3% that you claimed. That variation is inconsequential to the big picture of CO2's global warming effects. Climatologists and atmospheric scientists of course got all excited about that tiny variation, because that is their narrow, microscopic specialty. Why do you persist in insisting that clouds are indicators that the atmosphere is uniformly dense? dhogaza already explained to you that clouds are not made of gas molecules, so their distribution and even existence is not evidence of gas molecules being unevenly distributed. If you want more detailed explanations, blogs are not the right place. Go look at Ray Pierrehumbert's book on planetary atmospheres, to which I pointed you earlier.
  37. CO2 measurements are suspect
    Tom Dayton, Thanks much for the reference to Pierrehumbert's book.
  38. CO2 measurements are suspect
    Chris, Mizimi, and Tom Dayton, Thanks for a really interesting discussion of airborne CO2 concentrations. As a philosopher and not a scientist, I am more interested in assumptions that are made when measurements are taken. Chris' remarks seem to assume that CO2 is well-mixed in the atmosphere and that, for that reason, the fact that the measurement stations are located on the surface will provide an accurate picture of airborne CO2 concentrations. Now, I wonder if there are airborne measurement stations and if they are distributed throughout the atmosphere in a way that would make them as effective as the ground based stations. I doubt that they are because they would be very expensive. Satelites are very expensive too and they would use a different technique of measurement. So, my tentative conclusion is this: it seems that there is not a regime of measurement in the atmosphere (all the way up) that could serve to confirm the hypothesis that CO2 is well-mixed throughout the atmosphere. Am I right?
  39. Is the airborne fraction of anthropogenic CO2 emissions increasing?
    Theo, I don't know if there is a single article describing all the methods in detail, because different methods are used by spacecraft versus aircraft versus ground stations. But a description of the collection method on Mauna Loa is on NOAA's site. And on the AIRS site, click on the two links in the section titled "Measuring CO2 from Space with AIRS."
  40. Is the airborne fraction of anthropogenic CO2 emissions increasing?
    There is a 3% variation in the mid-troposhpere (5 miles) and no data on CO2 close to the earth. If the atmosphere is mixed well in that layer it is surely less well mixed at lower levels. If you are seeing a rise in CO2 levels how would you really know whether you were in a density wave or not? And as for clouds which reside at about 2 miles - they are indicators that the atmosphere is not uniformly dense. It appears that real CO2 data would be needed from literally millions of sampling points at varying strata not just the 200 or 300 stations that are used.
  41. Is the airborne fraction of anthropogenic CO2 emissions increasing?
    Tom Dayton and cbrock, thank you for answering my question, putting me to materials, and carrying on the conversation. If I may ask another, could you point me to an article on techniques of measuring airborne carbon dioxide concentrations?
  42. Is the airborne fraction of anthropogenic CO2 emissions increasing?
    Tom Dayton - the graphic from NASA depicts widespread, highly varying concentrations of CO2
    On what did you base your "highly varying" comment? Was it because they used a full spectrum of color (blue to red) to portray the +/- 1.3% variance (with most of the globe falling into a range of < 1.3% variance), or is it because you actually think the +/- 5 PPM range is really "highly variant"? Just curious.
  43. Is the airborne fraction of anthropogenic CO2 emissions increasing?
    If that were true then all molecules of any type would be equally distributed - including clouds. And since clouds are here and there - so must be molecules.
    Clouds are made up of droplets of water or small bits of ice, not individual molecules of H2O, so your comment regarding clouds is irrelevant.
    Also, the NASA CO2 map belies the idea that CO2 is evenly distributed.
    and
    http://sustainablog.org/files/2008/10/nasa_co2map.jpg
    Depends on your definition of "evenly distributed". The NASA AIRS plot you reference has a scale of 376-386 PPM, or 381 +/- 5 PPM. That's 381 PPM +/- 1.3%. That's extremely close to "evenly distributed". The press release is actually a bit weird, the AIRS data quantifies the "lumpiness". It's always been *known* that it takes time for CO2 (and other gasses) to become distributed by wind etc throughout the atmosphere - if you crack a tank of pure CO2 obviously the CO2 concentration near the tank will be higher than the average in the atmosphere. But once the tank runs out, the CO2 will rapidly disperse and that's it. So this isn't new knowledge at all. It's just quantification of how close to being 100% well-mixed the atmosphere is. We can measure it now, couldn't before, that's all.
  44. Is the airborne fraction of anthropogenic CO2 emissions increasing?
    NASA CO2 graphic http://sustainablog.org/files/2008/10/nasa_co2map.jpg Tom Dayton - the graphic from NASA depicts widespread, highly varying concentrations of CO2 - if CO2 was diffused evenly the color on the globe would be just one color.
  45. Is the airborne fraction of anthropogenic CO2 emissions increasing?
    ralphiegm, observations trump what you or anyone else "thinks." Also, you are incorrect that all kinds of molecules must be distributed to the same degree; just one example is water vapor's low concentration in the stratosphere versus lower, versus CO2's much more even concentration across those altitudes. Read the above comment by cbrock, and click the links in my above comment.
  46. It's cooling
    John Cook: Comparing the OHC results from the: 1)Upper 700 meters : 0.089 Wm^−2 (data source:http://climexp.knmi.nl/daily2longer.cgi, and the trend obtained in EXCEL) 2)Upper 2000 meters: 0.77 ± 0.11 Wm^−2 It is clear that the heat was sequestered in the Deep Oceans by the Termohaline Circulation, and that explain why the SST warming trend was near zero between 2003 and 2008. From this numbers is clear that if the Termohaline Circulation Shut Down then a BLAST OF HEAT will occur in the Upper Ocean and Atmosphere. Is there any current Climate Model of how much the warming will accelerate if the Termohaline Circulation Shut Down?
  47. Is the airborne fraction of anthropogenic CO2 emissions increasing?
    I think the idea that CO2 is diffused evenly througout the atmosphere is bogus. If that were true then all molecules of any type would be equally distributed - including clouds. And since clouds are here and there - so must be molecules. Also, the NASA CO2 map belies the idea that CO2 is evenly distributed. So the sampling for CO2 must be worldwide - not from few hundred stations.
  48. Is the airborne fraction of anthropogenic CO2 emissions increasing?
    Theo Goodwin: It is sometimes assumed by non-scientists that heavier gas molecules must be found closer to the earth's surface. However, for long-lived species such as CO2, atmospheric mixing (air motions) very effectively stirs up all the gases together so that they are not vertically separated. As one gets in the upper atmosphere (at very low pressures, approaching space), this is no longer true, but this region represents a tiny fraction of the mass of the atmosphere. This does not mean that all gases are perfectly evenly mixed, however. Obviously, near CO2 sources the concentrations will be higher, and near CO2 sinks (such as growing vegetation), the CO2 will be lower. So the end result is a patchiness to atmospheric CO2. There is a seasonality to this, since most vegetation is in the northern hemisphere. This seasonal cycle of CO2 is referred to as the "breathing" of the planet as the vegetation takes up CO2 during the growing season and gives it up during the fall and winter. The CO2 measurements report whatever the CO2 concentration is at a given place and time. Most of these measurements are extremely accurate and precise--a great deal of effort goes into assuring constant calibration standards and reproducibility. One has to average the CO2 measurements over the annual cycle and over the globe to get the global mean value. Hope this helps.
  49. Is the airborne fraction of anthropogenic CO2 emissions increasing?
    Theo Goodwin: CO2 is well mixed throughout the atmosphere--horizontally and (all the way up to the stratosphere). See the Skeptic Argument CO2 Measurements are Suspect. In addition to John's original post there, read the comments by Chris, John's "Response" in the green box within comment 16, and the new comment by me.
  50. CO2 measurements are suspect
    An AIRS press release noted that the AIRS data "complement existing and planned ground and aircraft measurements of carbon dioxide." Complement, not replace, because different tools measure CO2 in different vertical locations. More info on AIRS is available on the AIRS web site. The AIRS data for a recent two weeks can be seen on an interactive, rotating globe on JPL's "Eyes on the Earth 3D" web site. (On my Mac, it works properly in the Safari browser but not in Firefox; but my installation of Firefox doesn't work quite right, so it might be fine on your computer.) At the top left of the page, click the "AQUA" button. Then on the right side of the page, click the "CO2" button to show CO2 levels in the mid-troposphere as colors on the globe. The dates shown are above and to the left of the globe. Now drag the globe to rotate it. Click on the AQUA satellite to see the AIRS instrument. Discussion of CO2 being well mixed is on page 79 of Ray Pierrehumbert's book Principles of Planetary Climate, which is available free on line (and will be published in paper in 2010).

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