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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 75501 to 75550:

  1. Just Deserts: Winning the 2011 Eureka Prize
    A big cheer for John and the whole SkS team! And I would add to that my sincere thanks for everything they've done to promote education about climate change and its ramifications. This site is a fantastic resource for anyone interested in the subject.
  2. Just Deserts: Winning the 2011 Eureka Prize
    Well done! A small reward for a lot of hard work.
  3. Just Deserts: Winning the 2011 Eureka Prize
    Encore! Encore!
  4. Just Deserts: Winning the 2011 Eureka Prize
    Congratulations on receiving a much deserved award!
  5. Just Deserts: Winning the 2011 Eureka Prize
    Congratulations to John and all other contributors!
  6. Just Deserts: Winning the 2011 Eureka Prize
    This is what happens when you create and share a website of public interest. Congrats to John and his team !
  7. CO2 is just a trace gas
    here is another comparison of trace gases. Hydrogen Sulfide - H2S. it occurs naturally typically in swamps and sewers as well as emmitted from volcanoes. 0.00047 ppm is the recognition threshold, the concentration at which 50% of humans can detect the characteristic odor of hydrogen sulfide,[14] normally described as resembling "a rotten egg". Less than 10 ppm has an exposure limit of 8 hours per day. 10–20 ppm is the borderline concentration for eye irritation. 50–100 ppm leads to eye damage. At 100–150 ppm the olfactory nerve is paralyzed after a few inhalations, and the sense of smell disappears, often together with awareness of danger.[15][16] 320–530 ppm leads to pulmonary edema with the possibility of death. 530–1000 ppm causes strong stimulation of the central nervous system and rapid breathing, leading to loss of breathing. 800 ppm is the lethal concentration for 50% of humans for 5 minutes exposure (LC50). Concentrations over 1000 ppm cause immediate collapse with loss of breathing, even after inhalation of a single breath. http://en.wikipedia.org/wiki/Hydrogen_sulfide
  8. Just Deserts: Winning the 2011 Eureka Prize
    Congrats. Well deserved.
  9. Just Deserts: Winning the 2011 Eureka Prize
    A heart warming endorsement for the hard work you and your team do. I have been referring confused friends and family to you excellent website for over a year now. Cheers to you.
  10. Lessons from Past Climate Predictions: IPCC TAR
    Is it possible to put a marker on the graphs for this and the other 'lessons from predictions' articles, that shows exactly what part of the graph was predicted? In this case, the TAR was in 2001, I presume it included data up until 2000, so forecast is from that date, with the prior being hindcasting. Might be helpful for folks to see exactly how much prediction there is - the rest indicates how well their model fits the measured data, but isn't an actual prediction, per se.
  11. Just Deserts: Winning the 2011 Eureka Prize
    Congratulations, well deserved.
  12. Just Deserts: Winning the 2011 Eureka Prize
    Congrats guys, well deserved. Kind of makes the WUWT best science blog voted by people who don't know what they are talking about look a bit silly now.
  13. Philippe Chantreau at 19:19 PM on 10 September 2011
    Just Deserts: Winning the 2011 Eureka Prize
    Congrats to John and all moderators. This is a well deserved accomplishement and a meaningful award, not the internet poll type.
  14. Just Deserts: Winning the 2011 Eureka Prize
    Well done - richly deserved!
  15. Just Deserts: Winning the 2011 Eureka Prize
    Good on ya John ! And the whole SKS Team ! You are very worthy recipients of this well deserved honour !
  16. Just Deserts: Winning the 2011 Eureka Prize
    A superb contribution to the understanding of this important science deservedly recognised by this highest of accolades. You are entitled to boast a bit!
  17. Just Deserts: Winning the 2011 Eureka Prize
    Well done all!
  18. Dessler Demolishes Three Crucial 'Skeptic' Myths
    Dana. I can't speak for climate modeling, but 'error bars' in my line of work are just a way of graphically representing deviation around the mean-to ensure that any results are statistically significant. The larger the deviation, the more likely it is that the mean is due to chance alone. That's why we often employ so many field replicates in our analyses-to reduce the total deviation by having a sufficiently large sample size!
  19. Just Deserts: Winning the 2011 Eureka Prize
    Congratulations, Team - well deserved.
  20. Just Deserts: Winning the 2011 Eureka Prize
    Well done John, your service to cause of dispelling the lies about Global Warming have been absolutely amazing. Keep up the fantastic work.
  21. Just Deserts: Winning the 2011 Eureka Prize
    Bravo from across the ocean.
  22. Climate's changed before
    stonefly @214, below is a proxy of temperature over the last 5 million years. As you can see, significant low temperature episodes (glaciations) only occur the last 3.5 million years, and the large glaciations which we are familiar with from popular culture are a feature only of the last on million years. Here is a temperature reconstruction of the last 65 million years to put that into perspective. Note that the oxygen isotope "thermometer" is differently calibrated depending on the level of ice, so the first section is not strictly comparable to the last section of the graph. Over the last 600 million years,, every period of glaciation has coincided with CO2 concentrations less than 1000 ppmv. Note that this graph has an effective resolution of 10 million years. The entire period of the recent glaciation (double the length of the first graph) would appear as just one point on that graph. Obviously a lot can happen in 10 million years, and more detailed measurements have indeed shown in the episodes of glaciation during high CO2 levels as shown above, the duration of the glacition was short (< 10 million years) and that during the glaciation, CO2 levels where low (< 1,000 ppmv).
  23. CO2 is just a trace gas
    Tom Curtis - 40 W/m^2 escapes directly through the atmospheric window. However, ~160 W/m^2 leaves the ground through various means (IR, evaporation, thermals, minus 333 W/m^2 back-radiation). And ~80% of that energy leaves the surface via IR. But yes, convection is a major contributor to that heated atmosphere being able to radiate to space. A good thing, too - an average temperature 10 degrees C under boiling would be, um, uncomfortable...
  24. Just Deserts: Winning the 2011 Eureka Prize
    Aye, congrats John -- and a hearty ditto to KR @ 3.
  25. Just Deserts: Winning the 2011 Eureka Prize
    And also congrats to the team supporting John here. A true labor of love (since, after all, you're not getting paid for it), and very well done - contributors, moderators, and the regulars who spend time posting.
  26. Just Deserts: Winning the 2011 Eureka Prize
    Thumbs up, John Cook! Well deserved. You've put a heck of a lot of work into this, and this is good recognition of an impressive effort.
  27. Just Deserts: Winning the 2011 Eureka Prize
    Please add my hearty congratulations to John and all at SkS on a thoroughly well-deserved win!
  28. CO2 is just a trace gas
    Just to add clarity, by using English, to the equations above: 1) A* + B -> A + B_ : excited GHG molecule A increases the velocity of non GHG molecule B (raising the temperature) 2) A + B_ -> A* + B : GHG molecule A collides with non GHG molecule B, becoming excited and robbing molecule B of velocity (lowering the temperature) 3) * + A -> A* : Infrared radiation strikes GHG molecule A, exciting it 4) A* -> A + * : Excited GHG molecule A emits infrared radiation, becoming de-excited
  29. CO2 is just a trace gas
    86, Dana69,
    So it appears that whatever some IR absorbing molecule A* (CO2 , H20 , CH4 etc) does , there is at least one thing it doesn’t and it is to “heat the atmosphere”."
    This is wrong for three reasons. First, your explanation assumes an unchanging system at equilibrium. But what we are talking about is adding more A to that system, which will change the balance of the equations (after raising the temperature). Second, the equations you've been given all work for a closed system in equilibrium, which leads us to the last point, which is... Third, there are more equations to consider (I've numbered them to be able to sort them out). These are what you've considered so far:
    (1) A* + B -> A + B_ (2) A + B_ -> A* + B The conclusion that follows is that the number of A* (vibrationnaly excited molecules) is constant."
    This conclusion is wrong unless the system is in equilibrium (which it can't ever be, because the sun sets and rises, adding more or less * to the system, so it is constantly changing). The big problem with this is that set of equations is incomplete. The system is not closed (it has differing amounts of IR entering and leaving) and is not in equilibrium until it has warmed (if you increase the amount of A (CO2) in the system). You have two more equations:
    (3) * + A -> A* (4) A* -> A + *
    Here, to be consistent with the previous notation, I am using * to represent the introduction of infrared radiation to the system, to excite a CO2 molecule (A). What is important to recognize is that these equations are not in a simple 1 to 1 equilibrium, and so the balance is more complex. First, equation 4 happens a lot less than equation 1 lower in the atmosphere, it balances more and more as you get higher up and the air is less dense, so collisions (Eq. 1 and 2) are less likely to happen, until you reach a point where equation 4 happens more than equation 1. So ultimately the balance in these equations depends on how often 1 and 2 occur, which is determined by the temperature and density of the atmosphere (since temperature affects average velocity of the molecules) and also the amount of A* in the atmosphere, which is altered since equation 3 elevates the amount of A*. The frequency of equation 3 depends on the amount of infrared coming into the system, which is dependent not only on the temperature of the surface but also the temperature and composition of the nearby layers of atmosphere. Equation 3 also depends on the amount of A/CO2 in the system. More A means more chances to intercept IR, and so more chances to become A*, and so more chances for equation 1 to occur (passing that energy on to B and heating the system). Equation 4 depends almost entirely on the amount of A* (excited CO2) in the system, which depends on the rates of equations 1, 2 and 3. Lower in the atmosphere, it doesn't get to come into play as much, because equation 1 robs the atmosphere of A* so quickly (100 such collisions [Eq. 1] occur on average before it is able to emit [Eq. 4]). Higher up the reverse is true, so that equations 2 and 4 happen more often, and in that case CO2 actually acts to cool the stratosphere. So I'm afraid, yes, CO2 does heat the atmosphere, but the interaction is far, far more complex than the simple two equation scenario that your chemist friend has presented, and the answer to how much requires understanding all of the factors, including how often collisions occurs (eq. 1 and 2), how much IR is entering the system (eq 3), and how long a CO2 molecule "waits" before emitting IR (equation 4) relative to the rates of equations 1 and 2. But most importantly, the question is not "does A heat the atmosphere?" but rather "does increasing A heat the atmosphere beyond what it was before the increase?"
  30. Climate's changed before
    Bibliovermis at 09:18 AM Sorry I missed your link. I went right to google. Your link explains the carbon 12 - carbon 13 deal right away. I'll read it now.
  31. Climate's changed before
    Tom Curtis at 09:47 AM on 10 September, 2011 stonefly @210, orbital forcings are only as significant as they have been when the Earth is cool enough to have ice caps. Throughout most of Earth's history CO2 has been the major determiner of the surface temperature (thanks to the remarkable stability of our sun). I can tell this is going to take a lot of studying, but I want to understand this. I looked at a chart which showed glaciations approximately every 100,000 years going back to about a half million. Are there any glaciation charts that go back further? **** I suggest you watch Richard Alley's 2009 lecture to the AGU for a brief summary of the details. I did watch that lecture. It was interesting and informative. Only I wish I could have seen the laser on the slides.
  32. Climate's changed before
    Bibliovermis at 09:18 AM The reading gets deep. I'm doing a lot of googling for definitions. After I struggle with it for a while, maybe I'll get an understanding. One question I have now, though. They talk about carbon 13. I know that carbon 13 makes up only between 1% and 2% of carbon. I don't understand that. Does carbon 13 separate from carbon 12 and form CO2 that is all carbon 13? I know I'm going off on a little bit of a tangent. Anything you know about it would help, or if you could steer me in the right direction. Thanks.
  33. Climate's changed before
    stonefly @210, orbital forcings are only as significant as they have been when the Earth is cool enough to have ice caps. Throughout most of Earth's history CO2 has been the major determiner of the surface temperature (thanks to the remarkable stability of our sun). I suggest you watch Richard Alley's 2009 lecture to the AGU for a brief summary of the details.
  34. CO2 is just a trace gas
    KR @89, a slight nitpick. 40 W/m^2 of the surface radiation escapes to space, so the energy absorbed by the atmosphere from the surface by radiation is 356 W/m^2. More importantly, Trenberth and Fasullo quantify energy transports from the surface to the atmosphere. They do not quantify energy transports within the atmosphere, and within the atmosphere, or more specifically the troposphere, convection dominates over radiation as a means of energy transport. As I understand it, the reason for this is that it would take weeks (?! certainly days) for the atmosphere to reach a purely radiative equilibrium while it only takes hours to establish a convective equilibrium. Consequently the troposphere has a lapse rate determined by convection rather than radiation. Dana89 is right if he thinks this face weakens the greenhouse effect. If the troposphere's temperature profile was determined by radiation rather than convection, the Mean Average Global Temperature would be closer to 90 degrees C than to 15! It is only because convection reduces the greenhouse effect that the surface of the Earth is inhabitable! But reducing the greenhouse effect is not eliminating the greenhouse effect. Since the 1960's, the effect of convection on the greenhouse effect has been fully taken into account by atmospheric scientists, and their predictions, including the prediction of increased surface temperatures as a result of increased CO2 concentrations incorporate that fact, and are based on it. The only way to find solace in the dominance of convection is to studiously pay attention to that one fact, and ignore all the others that you find inconvenient.
  35. Conspiracy Dog-whistling about GRL and the New Dessler Paper
    Is it just me, or is the Watts/Pielke Sr etc response an eerie microcosm/metaphor/analogy/whatever of the way denialism works? 1) Encounter inconvenient (ho ho) facts 2) Without checking for context (for obvious reasons) spray out tendentious 'facts' of your own 3) Sit back and wait for howls of outrage/sober-disproving-of-your-"hypothesis", and then wait for 1)...
  36. Climate's changed before
    The PETM event (Paleocene-Eocene Thermal Maximum). Skeptical Science: CO2 Currently Rising Faster Than The PETM Extinction Event
  37. Lessons from Past Climate Predictions: IPCC TAR
    Whoops yes, good catch michael, thanks. Getting anything published in the mainstream media is always a challenge. If I can get this published as a book, then hopefully it would at least get a little media attention (as was the case with John and Haydn's book).
  38. Climate's changed before
    I've been following global warming for quite a while, with growing interest. I have discovered many informative posts on this site and decided to register. I can grasp the idea that changes in orbit and solar activity can force climate change, and that greenhouse gases amplify the trend. I can also grasp that our massive dump of CO2 into the atmosphere could force a climate change. My question is this, can anybody point out a time in the past when CO2 did the forcing, rather than an orbital cycle or solar activity?
  39. CO2 is just a trace gas
    Dana69 - The Stephan-Boltzmann law applies everywhere, at all times. Objects always have an absorptivity, and an emissivity, and those spectra match at thermal equilibrium. Convection (thermals) accounts for ~17 W/m^2 of energy rising from the Earth. Evaporation is around 80 W/m^2, while IR averages 396 W/m^2 coming off the surface, meaning that thermal radiation is >20x convection. Please see Trenberth 2009, Fig. 1, for details. Note that without convection, we would be much warmer - convection helps move warm air up to where it can radiate to space. But the majority of that energy is carried by thermal radiation. And please, read that Trenberth article carefully - convection is very noticeable, but not dominant in terms of energy transfer when you actually run the numbers. There have been any number of posters on any number of blogs who make a common sense error in that regard, and it always seems to take quite some time to correct such misapprehensions.
  40. Spending A Week Above Arctic Circle On M.S. Fram Off Greenland’s West Coast
    Interesting that every pic has a lean to the right.
  41. Conspiracy Dog-whistling about GRL and the New Dessler Paper
    "for some reason clouds are going to stop major climate changes this time even though they never did so in the previous 800,000 years". Exactly Scott, or in all the millions of years before that. I have been asking this obvious question for some time. Past climatic changes tell us there is no short term feed back mechanism preventing climate change. Perhaps Plimer could explain this to Spencer. The point is so obvious that it is impossible to see any rational reason (excluding ideology) for Spencer to persist with it or for anyone to take it seriously.
  42. Lessons from Past Climate Predictions: IPCC TAR
    Immediately under figure 2 it says "mid 19th centuary" twice. Do you mean "mid 20th centuary"? Excellent post. How can a summary of these projections get published in the mainstream media?
  43. CO2 is just a trace gas
    KR, Thanks for your remarks. Just curious, isn't convection a stronger force than radiative force in the troposphere? My understanding is that the Stefan-Boltzmann law applies in the stratosphere where convection and conduction are weakest. Respectfully,
  44. Republican Presidential Candidates vs. Climate Science
    I think it's worth quoting Cardinal Bellarmine own words (taken from the post linked by Composer99):
    I say that if there were a true demonstration that the sun is at the center of the world and the earth in the third heaven, and that the sun does not circle the earth but the earth circles the sun, then one would have to proceed with great care in explaining the Scriptures that appear contrary; and say rather that we do not understand them than that what is demonstrated is false. But I will not believe that there is such a demonstration, until it is shown me. Nor is it the same to demonstrate that by supposing the sun to be at the center and the earth in heaven one can save the appearances [predict accurately], and to demonstrate that in truth the sun is at the center and the earth in the heaven; for I believe the first demonstration may be available, but I have very great doubts about the second, and in case of doubt one must not abandon the Holy Scripture as interpreted by the Holy Fathers.
    His position is the same that the Roman Church had maintained from the early times and explicitly stated by Saint Agustine. On the scientific positions taken by some christians of his times, Saint Augustine wrote "It is too disgraceful and ruinous, though, and greatly to be avoided, that he [the non-Christian] should hear a Christian speaking so idiotically on these matters, [...]". Those who like to identify themselves with Galileo should be more carefull, the risk of "speaking so idiotically on these matters" is high.
  45. CO2 is just a trace gas
    Dana69 An important element of radiative heating/cooling is that emissivity equals absorptivity when the object (in this case the atmosphere) is at thermal equilibrium. If the atmosphere is hot enough it will emit more energy than it is absorbing, and it will cool. If it's cool, and receiving more energy than it's emitting, it will warm up. this is governed by the Stefan–Boltzmann law. If the atmospheric temperature is not at the point where its emissions match incoming IR, it will change temperature.
  46. Spending A Week Above Arctic Circle On M.S. Fram Off Greenland’s West Coast
    I though it was "Pay attention to the Pine Island Glacier in Antarctica" Nice report.
  47. CO2 is just a trace gas
    Climate is a complex subject. GHG theory states “greenhouses gases” – water vapor, CO2 and methane (plus some others) - absorb longwave radiation and re-emit radiation both up out of the atmosphere and back down to the earth’s surface. And without this absorption of longwave radiation the earth would be 35°C cooler at its surface. (do I have this correct). If so how would you explain dynamical collisional equilibrium: CO2 emits infrared radiation not only of the same intensity but also of a very similar frequency as the one it absorbs. (this next part is not me, it is from my professor friend who indicates that the term "heating" with regards to vibrational activity of molecule collisions are wrong. Again, these are not my remarks, but seem persuasive. "What Happens when a Greenhouse Gas Absorbs Energy? Once a gas molecule has absorbed radiation from the earth it has a lot more energy. But in the lower 100km of the atmosphere, the absorbed energy is transferred to kinetic energy by collisions between the absorbing molecules and others in the layer. Effectively, it heats up this layer of the atmosphere. This is only half the story and because of seeing only the half story , the conclusion is wrong. What you say is the following : A* + B -> A + B_ In words – the vibrationnaly excited molecule A* interacts with a molecule B , its excited state decays to A and the molecule B increases its kinetic energy to B_ . This is right. But what you forget is that by time symmetry we have also : A + B_ -> A* + B The molecule A interacts with a molecule B_ , its vibrationnal state excites to A* and the molecule B_ decreases its kinetic energy to B. This is btw the process that makes a CO2 laser work . In LTE what is the basic hypothesis in all these posts we can even say more , namely that the rate of both processes is exactly equal and we have an equilibrium that can be written : A* + B A + B_ Please note the difference to the initial A* + B -> A + B_ ! The conclusion that follows is that the number of A* (vibrationnaly excited molecules) is constant . Also another way to say the same thing is that the distribution of the kinetic energy of the B molecules is constant too. Still another independent way to find again the same result because they actually all use same concept of energy equipartition , is to note that the distribution of vibrationnal energy levels is constant for a given temperature (Maxwell Boltzmann law). So it appears that whatever some IR absorbing molecule A* (CO2 , H20 , CH4 etc) does , there is at least one thing it doesn’t and it is to “heat the atmosphere”." Again, not my work, but it was explained to me, although I do not have the skills to verify.
  48. Republican Presidential Candidates vs. Climate Science
    Josh Rosenau of the NCSE has an interesting discussion of the Galileo comments made by Rick Perry. He finds that the primary objections, by the authorities of the day, to Galileo's work were theological (as per his quote by Cardinal Bellamine (Bellamino?)), while acknowledging other natural philosophers of the day disagreed with Galileo. He suggests that the natural philosophers' paradigm of the solar system was in flux at that time rather than a simple, toggle-like switch from geocentrism to heliocentris.
  49. Republican Presidential Candidates vs. Climate Science
    The only reason way people use the Galileo analogy is to try to portay science as a faith. To any informed person, it just shows a profound ignorance of history in general and of the Galileo trial in particular. To add to the NYT piece, even inside the Catholic Church some scientists supported Copernicus and Galileo views, like, for example, Benedetto Castelli, a benedictine friar.
  50. Lessons from Past Climate Predictions: IPCC TAR
    where will you publish the "booklet/..." ??
    Response:

    [dana1981] That depends if I can find a publisher willing to publish it.  If not, we'll probably just publish it on SkS.

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