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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 123801 to 123850:

  1. Visual depictions of CO2 levels and CO2 emissions
    You're almost certainly correct, Phillipe, as we know how much people are destroying the rain-forests of Africa & South America. This isn't just putting CO2 into the atmosphere, it is also leading to reductions in regional rainfall, the loss of valuable soil nutrients, increased risk of exposure to disease vectors (like Ebola) & the endangerment of thousands of species of animals & plants. I don't like to sound pessimistic, but I suspect that Homo Sapien Sapien will be one of the shortest lived species on the planet to date!
  2. There's no empirical evidence
    Riccardo, Yes, I know there ''there's not just CO2 around''. That is exactly my point. Alarmists are currently blaming everything on just some added ppm:s of CO2, where there obviously also exist other explanations of, and reasons for, global warming. And no, I did not use 'wrong logic'. I did not claim that current warming 'can not' be due to CO2. I just said that there could be other reasons as well. Riccardo uses 'wrong logic' when he blames me of something I did not claim. Apparently Riccardo is not familiar with the language of logic (A implies B, and so on), or he would have seen my point, instead of jumping onto something I did not write. I was simply pointing out (as has others before me, se comments 2, 7, 10, 12) that you cannot prove backward implication, from the knowledge of existing forward implication. I will expand upon my own smoke example: We know that tyres burning cause black smoke. Suppose we know beforehand that burning of tyres is taking place in a suburb. Suppose we see enormous amounts of smoke from a distance. The alarmist would then say: 'Oh my, what a lot of tyres they must be burning!'. Yes, some smoke did come from the tyres, but what we did not know was that 98% of the smoke came from a chemical factory that was on fire.
  3. Is CO2 a pollutant?
    The site Sceptical science should offer a way out of the mud slinging that gets nowhere and is unfortunately all to common with this topic. So what have I picked up from the discussion! CBDunkerso ...........As to your convection hypothesis... it fails because, amongst other things, greenhouse gases do not retain heat within themselves. They absorb and then immediately re-emit the infrared radiation..... However this is contradicted by Carrot Eater ....By the way, CO2 doesn't always instantly radiate a photon as soon as it absorbs one. It can collide with neighboring molecules and thus warm up that pocket of air...... I would tend to side with carrot eater- but now the energy in the form of vibrational KE can be picked up by nearby molecules(most likely to be N2) Carrot Eater goes on to say But that's still fine; the CO2 will still emit at some rate set by the local temperature..... It can only radiate in one of two possible IR bands and it has just lost one ! Carrot Eater has reassured me by saying of the use of Stephan Boltzmann equation is not used in realistic calculations. .....Those are extremely simplified cartoon illustrations, to help show people the basic concepts of the energy balance without having to write thousands of equations. However thanks must go to Philippe Chantreau 151 who has given a link to Eli Rabbits final draft of his attempt to refute the G&T paper. However Eli uses in his refutation ....guess what....Stepthan Boltzman equation for atmosphere re-radiating back to Earths surface. Eli has been keeping quiet about this recent effort and I think I can guess why. I am disappointed with Ricardo when he tries to defend what must be a silly mistake. ...A molecule moving vertically up in a gravitational field for say 10Km in the absence of any other interactions would keep the same speed...-this is nonsense Not only does it contradict the conservation of energy it contradicts the force of gravity. From the Kinetic Theory of Gases The KE of a molecule is directly proportional to its absolute temperature In my post 101 ... I gave a typical question from any high school physics book in the planet I have also given answers-try it for yourselves-if you cannot cope then I think you will find it very difficult to understand this topic
  4. Dikran Marsupial at 21:08 PM on 18 February 2010
    Did Phil Jones really say global warming ended in 1995?
    One last comment on statistical significance, a more frequentist colleague kindly let me borrow his copy of "Statistical Inference" by Garthwaite, Joliffe and Jones (ISBN 0-13-847260-2), which says on page 72: "A related point is that rejection of H0 [the null hypothesis] implies a degree of disbelief in H0, but 'acceptance' of H0 simply means that there is little evidence against H0 and does not rule out other hypotheses. 'Failure to reject' is a better term than 'acceptance'" Of course if you cherry pick the start date then the hypothesis test is invalid in the first place as you have already looked at the data to select a period where the data don't supply sufficient evidence to reject the null hypothesis. Most of the "global cooling since X" or "lack of warming since X" are based on such cherry picking, for instance X is often 1998 or 2002, but not 2000. The reason why is fairly obvious. I suspect that 1995 was chosen as it is the earliest start date for which there is insufficient evidence to reject the null hypothesis; in which case it is in the same category. Phil Jones should be applauded for giving a straight scientific answer to the question without a trace of spin; that was left to the journalists to supply ;o)
  5. Skeptical Science now an iPhone app
    Great app John. I followed the Guardian thread yesterday and was pleased to see how many people had visited your site after reading the article. The best counter we have to propaganda are facts, and this is a superb channel through which to deliver rational arguments based on science.
  6. There's no empirical evidence
    guinganbresil, the increased absorption at 600 cm-1 due to CO2 together with the increase of the thermal radiation from the surface are indeed compatible. The former is a measure the extra heat trapped, the latter of the increased surface temperature. The overall OLR increases/decreases if the planet is out of equilibrium and is warming/cooling.
  7. Philippe Chantreau at 18:52 PM on 18 February 2010
    Visual depictions of CO2 levels and CO2 emissions
    Wow! Nice. I wonder what are the causes of plumes over equatorial Africa and South America in the NOAA vid. I'm leaning toward fires.
  8. Jeff Freymueller at 18:44 PM on 18 February 2010
    Visual depictions of CO2 levels and CO2 emissions
    The videos work now in Firefox. Fabulous.
  9. Visual depictions of CO2 levels and CO2 emissions
    John, I'm not seeing the videos in Firefox. The blocks of space where they should be are there, the object code is there behind the scenes, and I can copy the Youtube links into a new window and watch the videos directly, but nothing in this page.
    Response: Thanks for the heads-up, it's a glitch in my admin system that changes the YouTube code enough to break it in Firefox but not in Internet Explorer, hence I didn't notice the error.

    Yes, it's true, I use Internet Explorer :-(
  10. The Dunning-Kruger effect and the climate debate
    "if you sort it you are predisposing yourself to an expected outcome. Just pick pieces at random without any thought to what the outcome should be and see what you get" - I sense a fundamental failure of a science education here. We usually complain abut students graduating without learning some fundamental scientific facts and theories. But this comment (as is the case with so much of the denialism we see growing in volume) shows that a student has not been taught, or failed to learn, the scientific PROCESS. Still, you can always pick it up, effortlessly, from American crime shows on television.
  11. It's the sun
    It is arbitrary. I looked a little at other averaging methods. The general shape of the sunspot averaging results are similar. All show that an increase in global temperatures would be expected after 1920. I believe that the overall time period is of the order of 40 or more years. Other weighting factors may be more appropriate, but I don't know how to determine them. This approach is only for long term temperature studies. Short term temperature responses will neccessarily scatter around the longer trends. Since the Little Ice Age was likly the result of the lack of sunspot activity this shows that solar activity should not be ignored even though direct quantification cannot be derived. Is there any real reason to believe that greenhouse gasses are any more responsible for global temperatures than solar activity?
    Response: Is there any real reason to believe that greenhouse gasses are any more responsible for global temperatures than solar activity?

    This question is answered in The empirical evidence for an enhanced greenhouse effect. Just to clarify, greenhouse gases aren't the sole driver of climate but over the last few decades, the forcing from CO2 have been greater than any other climate forcing (as well as the fastest rising).
  12. There's no empirical evidence
    Figure 2C from Harries 2001 is being used to show that outgoing long wave radiation is decreasing as a result of CO2 and other greenhouse gases. Figure 2B (not shown) indicates an increase the range 750-1000 cm^-1. The net effect is an actual increase in OLR over time. This increase is shown spectrally in the other papers mentioned as well (Griggs 2004, Chen 2007). Although Harries 2001 writes it off as contaminated data - it is a real measurement and not an artifact (Griggs 2004). The increase has been measured in other satellite measurements of total OLR. The total OLR is increasing over time, not decreasing. The Earth's radiation balance is a function of the TOTAL OLR, not just the OLR in the CO2 band. It is a fallacy of composition to conclude that a reduction in the 15 um OLR is CAUSING Earth's warming when the TOTAL OLR is increasing. At most you could assert that the decrease in 15 um OLR would exacerbate warming caused by ANOTHER SOURCE.
  13. The Dunning-Kruger effect and the climate debate
    TOP at 13:31 PM on 18 February, 2010 That's most unfortunate. Having a grasp of the basic principles and at the same time a reluctance to accept the outcomes predicted by those principles is of course something only you can address. You might want to think of it all in the same way you do fastening your seat belt, or brushing your teeth. Failing those, Good Luck to you, I can't offer better!
  14. The Dunning-Kruger effect and the climate debate
    TOP, Spencer Weart's The Discovery of Global Warming is intended to be an overview--an introduction. If you want more detail, including the specific evidence backing up the experts' opinions, you are supposed to follow up elsewhere. One excellent place is here at Skeptical Science. But that addresses your objection only if you actually read the references that John (and others) provide. It sounds like you might benefit from, and appreciate, the overview by cce, The Global Warming Debate. But on that site, too, your objection to reliance on experts will be overcome only if you click on the links that cce provides to the sources of his info.
  15. The Dunning-Kruger effect and the climate debate
    doug_bostrom "You might want to get up to speed on this entire topic by reading Dr. Spencer Weart's excellent summary, here: The Discovery of Global Warming" I read through it. Thanks. But I still don't agree or better, I don't see what the point is. Doctor Weart frequently appeals to experts, in fact I see more appeal to experts than hard numbers and the equations and math models to go with them. I don't often go to popular TV series for wisdom, but a character on one of those crime scene investigation shows had a zinger when a colleague asked whether they should sort the pile of evidence first. She said, "No, because if you sort it you are predisposing yourself to an expected outcome. Just pick pieces at random without any thought to what the outcome should be and see what you get." I see Doctor Weart doing a lot of sorting based on an anachronistic disposition toward the outcome. I already had a grasp of the basic principles that those folks were using and haven't seen a compelling argument for the kinds of actions being proposed to combat it. Sorry, I still stick to my principles.
  16. The Dunning-Kruger effect and the climate debate
    In response to the emailed version of this article, and its reference to peer-reviewed papers even available by iPhone: peer-reviewed papers are great, the science MUST rely on them, but they are nearly useless for public policy debates. Why? Because they are too hard to read for people outside the field. But the whole point of the public policy debate IS to make the basic facts of the case accessible to the public, so that they can understand the truth of the matter: AGW is real, it is a real threat, we must deal with it by cutting GHG emissions NOW.
  17. The Dunning-Kruger effect and the climate debate
    TOP, as has been stated elsewhere, the ratio of carbon isotopes in natural CO2 is significantly different from that in CO2 from fossil fuels (due to the longer time carbon in fossil fuels has had to decay). Secondly, there probably is a saturation point above which increased CO2 will not lead to further increases in temperature, but are you prepared to bet your *life* on where that saturation point might be? The average temperature of the Carboniferous Era was 22 degrees C, compared to 14 degrees C today, so that suggests the threshold is very high indeed!
  18. Did Phil Jones really say global warming ended in 1995?
    Another point, RSVP, is that though base temperatures of cities might be warmer than their surrounding rural environments (by anywhere up to 1 degree C), there is absolutely *no sign* that cities are warming any faster-above that base-than the surrounding rural area. Indeed, if urban heat were the primary source of global warming, then the inversion layer/urban heat island should ensure that urban areas warm significantly faster than their surrounds. Yet this is clearly *not* the case. Many remote, rural areas are warming significantly faster than the nearest cities, which suggests a much less localized source of warming.
  19. Did Phil Jones really say global warming ended in 1995?
    Wow, #82 by RSVP really does show a complete lack of background knowledge. It's like when you enter 'chat' in some online video game and then suddenly realize the other person must be 13 or so. For the record RSVP, laying asphalt and emitting CO2 have the following similarity - both trap more of the incoming energy from the sun, increasing surface temperature. But the asphalt only does so over the area it is laid. The CO2 does it over the whole planet, and is the greater total effect by far. Your phrase "manmade solar energy being trapped that would otherwise not exist" is completely mixed up. (Is English your main language?) The correct thing to say about asphalt is "natural solar energy being trapped that would otherwise have been reflected back into space" Read the wikipedia article on urban heat islands. It's very clear that albedo, both in terms of the dark surfaces, and the geometry of the surface "urban caynon effect" is the main driver of UHI. Direct heating from human use of energy is less important. In other words, if you did an experiment where all the inhabitants of New York left the city for a year, it would still be an urban heat island while they were gone. As impressive as the UHI effect can be, not enough of the planet's surface is affected for UHI to make any noticeable contribution to global warming. Only truly global changes (like CO2) can cause that.
  20. Did Phil Jones really say global warming ended in 1995?
    RSVP, the amount of energy which is received by Earth-from the Sun-every year is 3.8 million *exajoules*. The total amount of energy generated from *all* human sources in a year is about 600 exajoules. So you see that your claim that our piddling thermal contribution is significant enough to warm the entire planet is like me saying that-if I pee in the ocean, it will turn yellow. No, where humans are impacting on global temperatures is on how quickly & easily *all* the planet's outgoing radiation can be re-emitted back out to space. In that regard, our contribution is *very significant*.
  21. Did Phil Jones really say global warming ended in 1995?
    RSVP said:
    What you just referred to as lower albedo due to asphalt is precisely manmade solar energy being trapped that would otherwise not exist. Conbustion (sic) energy is also man-made. For these reasons cities are warmer.
    Please go and read the Dunning Kruger thread. What you have just posted is absolute nonsense and shows that you know next to nothing about AGW.
  22. Did Phil Jones really say global warming ended in 1995?
    CBDunkerson "the energy generated by a city is absolutely minuscule in comparison to the energy of the solar radiation hitting that city... and the entire rest of the planet. Further, cities are not 'warmer regions' of the planet. They often (not always) tend to be slightly warmer than their immediate local surroundings due to lower albedo of asphalt and other factors, but this is nothing compared to places like Death Valley or the Gobi Desert. " The only source of global warming of concern (I thought) is that which precisely comes from humans. That of Death Valley or Gobi Desert have been around for ever and are not considered incremental. What you just referred to as lower albedo due to asphalt is precisely manmade solar energy being trapped that would otherwise not exist. Conbustion energy is also man-made. For these reasons cities are warmer.
  23. Did Phil Jones really say global warming ended in 1995?
    75, RSVP "SNRatio "Of course that is not the way we work in science, and I don't really understand where you have got these notions from." Answer. Maybe engineering. People who build the equipment you guy use. " So then, when there is a 94% chance a part is faulty, you say "no fault" because the null hypothesis of "ok" can not be rejected? That may actually explain a lot, but most engineers know better, and work mostly with confidence intervals when presented with estimation problems of the type we discuss here. And when they do tests, they care about the power. You are insisting on methods that cannot detect a 0.12 degC/decade warming trend. In a climatic context, that's insisting on blindness. But it is a strategy used to conceal facts: Running tests with too low power to detect effects, and with experiment repetitions that, like short time temperature series, tend to go both ways. "There is no effect."
  24. Philippe Chantreau at 08:11 AM on 18 February 2010
    Is CO2 a pollutant?
    The complete G&T09 comment sent to the journal that published it can be found here on top of the list: http://groups.google.com/group/rabett-run-labs?hl=en How G&T made it through peer-review is unclear. Perhaps something similar to the Soon-Baliunas piece.
  25. The Dunning-Kruger effect and the climate debate
    Well, this article has not necessarily increased the self-awareness of readers. We still see displays of this syndrome. Unfortunate.
    Response: Rome wasn't built in a day :-)
  26. Skeptical Science now an iPhone app
    I second the idea of an Android app. Kudos again to this site. It's been a bright spot in an otherwise dismal media onslaught of disgraceful misinformation in recent months/years. Thanks for the link, Doug. What a nonsensical tirade by Piers Corbyn. Contrarians don't like having their bunk arguments (or their "side" as he puts it) challenged.
  27. Dikran Marsupial at 07:03 AM on 18 February 2010
    Did Phil Jones really say global warming ended in 1995?
    From Peru @ 77 woodfortrees.org is a great site for generating plots for yourself, just the way you want them. For instance, here is the HADCRUT data from 1979 onwards, including the monthly data, 12 year running mean and the 1979-present trend. http://tinyurl.com/yf8729r The trends for RSS, HadCrut and GISSTemp are all very similar, the UAH one a bit less, but basically the surface trends look like they are in reasonable agreement with the satelite trends. A woodfortrees plot is available here, I have alterered the baselines to make the difference in trends easier to see (but the trends themselves are unaffected by the baseline) http://tinyurl.com/yh2vn4n woodfortrees is a great site, I recommend anyone interested in climate science to use it to test out what they read on the blogs. HTH
  28. Did Phil Jones really say global warming ended in 1995?
    RSVP, the energy generated by a city is absolutely minuscule in comparison to the energy of the solar radiation hitting that city... and the entire rest of the planet. Further, cities are not 'warmer regions' of the planet. They often (not always) tend to be slightly warmer than their immediate local surroundings due to lower albedo of asphalt and other factors, but this is nothing compared to places like Death Valley or the Gobi Desert. Thus, viewing cities as the 'source of heat' spreading around the planet, as with CO2, is incorrect. The heat contribution from cities directly is tiny compared to solar energy, greenhouse effects, and hydrological effects (i.e. heat going into or coming out of the oceans due to weather). With CO2 isolated sites like Mauna Loa, American Samoa, Barrow Alaska, and the South Pole all show the same results... but temperature series taken at those locations would be completely different.
  29. Skeptical Science now an iPhone app
    Touched a nerve, it seems. In the Guardian: "Deniers queue up to lambast Skeptical Science application developed by solar physicist John Cook. ... I'm not sure this is going to quell the climate wars raging at present, but it's an interesting development nonetheless. An Australian solar physicist called John Cook, who runs the popular Skeptical Science website, has developed an app which "lets you use an iPhone or iPod to view the entire list of skeptic arguments as well as (more importantly) what the science says on each argument". So the next time you're caught at the fag end of a wedding reception in an interminable one-way conversation with a reactionary uncle who's boring on about how "the climate's always changed", just switch on this app, hand them your iPhone, and proceed to the bar. In reality, of course, this is hardly likely to win round any sceptic, least of all your worse-for-wear uncle who, with or without the evidence presented to him by this app, will still continue to swear blind that climate change is a fiction made up by a clandestine world government-in-waiting because he's read about it all on his favourite blog, which just so happens to be frequented by an army of other reactionary uncles. One suspects this app will only act to increase the polarisation between the two sides of this "debate". (Still think a debate's going on? When was the last time you heard someone from either side say, "Thank you for this information. Actually, I'd never thought of it like that before. I'm now prepared to change my mind on climate change.") ... " More: iPhone app pitches climate change science against scepticism
  30. Did Phil Jones really say global warming ended in 1995?
    This is a great article. I am glad Phil Jones is getting some answers into print. Actually I think he chose his words very carefully and well. The tone of his points is right - being a scientist means having doubts and being skeptical. While some of the things might be seized on by whatever camp it is good for science to show what is known and what is not.
  31. Did Phil Jones really say global warming ended in 1995?
    Mr John Cook: Could you show the RSS and UAH lower troposphere data to compare it with the hadCRU and GISSTEMP data? And also show the MONTLY and 12-month moving average of all of them? Seeing the trends and variability of all our surface temperature metrics will be a great thing. Specially the LOWER TROPOSPHERE vs. SURFACE temperature trends!
  32. Did Phil Jones really say global warming ended in 1995?
    Wow this site is getting loads of comments these days. Deservedly so. The only significance of the question was how transparently, carefully, chosen it was to provide the answer required. But Prof Jones answered correctly, even if it was a bit of a trap. Those with more than one brain cell to rub together will appreciate the "significance" of his full answer.
  33. Did Phil Jones really say global warming ended in 1995?
    SNRatio "Of course that is not the way we work in science, and I don't really understand where you have got these notions from." Answer. Maybe engineering. People who build the equipment you guy use.
  34. Did Phil Jones really say global warming ended in 1995?
    CBDunkerson Sometimes it takes questions like this to realize how differently people can be thinking. My thinking is that since energy can't be destroyed, heat from warmer regions (cities for instance) makes its way around the planet contributing to an overall global warming effect. This explains my question about why not sample temperatures as is done for CO2. There is of course the upward IR ratiative cooling path to consider. If this path dominates, and basically "shorcircuits" any convective heating, local temperature increases wouldnt represent global warming at all, but instead isolated regional warming which would be completely dependent on the amount of energy discharged locally. It would seem therefore, that the only global warming that really matters, is that which is associated with measurements in locations that are far from human populations. The problem of course is that when making historical comparisons, a lot of the data has likely been taken from areas that have since become part urban sprawl.
  35. Working out future sea level rise from the past
    The polar ice caps would be GROWING if there were global warming, not shrinking. Sea levels would FALL, not rise.
    @JM: This is completely at odds with historical sea level and ice coverage reconstructions. Also, what you said can be refuted in a simple manner. Temperature varies with latitude, evidently. This means there's essentially a temperature threshold for the ice caps. The threshold can be thought of as existing at specific north and south latitudes. These threshold latitudes change if the temperature of Earth changes. Hence, if the temperature increases, the polar ice caps shrink. If the temperature drops, the polar ice caps grow.
  36. Did Phil Jones really say global warming ended in 1995?
    RSVP: [i]PS Addressing JonMoseley's comment "To be valid science, one must state that a measurement that is not statistically significant is equivalent to ZERO." Agreed. And personally, with all these spots on communication blunders, one notices that its the reader or audience that is always portrayed as at fault for not understanding or misinterpreting explanations. [/i] By that logic, we would have "science" declaring the trend is zero one month, and, for example, 0.15 the next month, because the trend persisted, but p-value moved from 0.0505 to 0.0490. Of course that is not the way we work in science, and I don't really understand where you have got these notions from. Except for them fitting very well in a denialist "paradigm". When we look at temperature trends, for example in the UAH series, we extend it backwards till we eventually can get some stability (we do), and then, using it as a raw estimate, check for significance. With the current level of fluctuations, we typically need more than 15 years to be sure. The stability is essential, otherwise we could talk about "significant cooling" every winter. It surely is significant where I live, but that has got nothing to do with climate. I have no problems accepting the possibility of global cooling, if you present stable and sigificant cooling trends for me. But it seems to be vary hard for many self-declared "skeptics" to accept the possibility of global warming, in spite of very stable warming trends. That's the difference between skepticism and denialism. I also wonder if a number of people are somewhat logically challenged, as they tend to take over-estimations of warming as "proof" that warming doesn't happen. Or failure of models to correctly predict the processes going on as "refutations of AGW". You can die from a gunshot regardless of the people involved in the incident having a correct understanding of the trigger mechanism or not.
  37. Dikran Marsupial at 05:11 AM on 18 February 2010
    Did Phil Jones really say global warming ended in 1995?
    RSVP (69) Jon Moseley's comment demonstrated a common fallacy in interpreting the result of a frequentist hypothesis test. Being unable to reject the null hypothesis is not the same as showing the null hypothesis to be true. Absence of (compelling) evidence is not (compelling) evidence of absence. Here are some musings on the way this misunderstanding arises: The way published research should proceed is very much the same way a good chess player plays chess. A weak chess player will simply play the most promising move he sees, without really considering his opponents reply. A good chess player on the other hand plays the strongest move he can find that his opponent can't counter. Likewise a good scientific paper doesn't advance a strong claim that is not solidly supported by the data. In this way the paper is likely to result in scientific progress as it can't be easily refuted. A good scientist therefore makes the strongest claim that he considers to be irrefutable, rather than the strongest claim that merely *could* be supportable given the evidence. So like chess it is a min-max game. Thus we are INITIALLY taught to treat statistically insignificant results as "being equivalent to ZERO" as a guard against making any claim based on statistically insignificant evidence (and indeed Jones does not). As a first approximation, that is reasonable, however once your education progresses to the point where the principles of hypothesis testing, rather than simply the practice, are better understood, it becomes clear that this is just an approximation, and the meaning of the p-value is actually rather subtle (and doesn't really answer the question you thought you were asking, at least that is the Bayesian position). However that is how we should treat the evidence for OUR claims, not how we should treat the evidence for the claims of OTHERS we would like to REFUTE, as it is a min-max game for both sides. So while "is equivalent to ZERO" is a reasonable maxim if we apply it to our own claims, it is a very poor maxim for refuting the claims of others as instead of the difference between maxim and truth being a useful safeguard, it becomes a fallacy. The reason that the reader or audience is portrayed as being at fault for not understanding or misinterpreting explanations is because of the Dunning-Kruger effect discussed on a previous thread sadly means it is often true. The impression is given by posters and/or journalists that make strong claims, quite obviously on the basis of a very shaky understanding of the facts. Were they to post questions asking for explanations of claims, rather than make easily refuted counter claims, and be open to the responses, the portrayal would not have resonance that it currently does.
  38. Skeptical Science housekeeping: iPhone app, comments and translations
    Actually, any plans to make this for the Pre? Given I'm about to buy one (I much prefer its interface to that of the iPhone), I'm a totally disinterested party. ;)
  39. Is CO2 a pollutant?
    angliss: If you want a really simple way to show somebody that not everything is a perfect grey body: just ask them to look around the room. Some things appear red, some blue, some green, even though they're being illuminated by the same light source. If the absorptivity were always constant over wavelength, this wouldn't be possible. You'd just see different shades of grey.
  40. Did Phil Jones really say global warming ended in 1995?
    RSVP, obviously CO2 and temperatures are different things and behave in different ways. For CO2 what is being measured is effectively the 'baseline' CO2 level... there are actually higher levels of CO2 downwind of industrial centers all over the world, but by the time winds would carry that CO2 to Mauna Loa (or any of the other remote measuring stations) the CO2 has diffused throughout the atmosphere and you are looking at effectively the MINIMUM value worldwide... which is why the different stations get matching values. For temperatures on the other hand there is no 'global minimum' which can be consistently detected at specific points. Instead, the global temperature values we get are 'averages' computed by taking readings at thousands of sites around the world and applying them geographically. In theory CO2 levels could similarly be computed as a global average in the same way that temperature is. This would result in values slightly higher than the baseline figures currently used. However, it would also require alot more monitoring stations and be subject to greater potential for error.
  41. The Dunning-Kruger effect and the climate debate
    TOP at 22:56 PM on 17 February 2010 C02 in ciculation as part of the natural carbon cycle versus C02 contributed to the atmosphere as part of fossil fuel combustion is easily distinguished by isotope ratios. You might want to get up to speed on this entire topic by reading Dr. Spencer Weart's excellent summary, here: The Discovery of Global Warming A few hours and you'll have a basic grasp of the phenomenon, warts and all.
  42. Did Phil Jones really say global warming ended in 1995?
    RSVP, it is called global warming becasue it is, well, global. This means the any region of the planet counts proportionally to its area; if it's large it will have a relatively large effect, if it's small it will be small. As easy as the definition of average. If the Earth was like Venus the temperature would have been "well mixed" like CO2 and we could have implemented just one station at Mauna Loa or anywhere else. Unfortunately (or maybe luckly ;)) it is not, so the tempeature at one single point tells nothing about the global average.
  43. It's the sun
    Cliff Oates, can you attribute any physical meaning to your linear weighting function? It looks a bit arbitrary.
  44. Did Phil Jones really say global warming ended in 1995?
    In comparing data, article states: "the areas omitted by HadCRUT are some of the fastest warming regions in the world" If this is about detecting "global" warming, why does regional warming even enter into the equation? If taking "proxy" CO2 measurements from a volcano in Hawaii makes sense, why not apply the same idea for measuring temperature? PS Addressing JonMoseley's comment "To be valid science, one must state that a measurement that is not statistically significant is equivalent to ZERO." Agreed. And personally, with all these spots on communication blunders, one notices that its the reader or audience that is always portrayed as at fault for not understanding or misinterpreting explanations.
  45. It's the sun
    Since sunspot activity is observed for numbers, energy and radiation charistics a complete thermal balance with the earth is a very difficult if not impossible task. I believe that the oceans with their tremendous heat capacity are the key to the earths global temperature. The sunspot numbers count could be used as an indication of the sun's variation from a nominal output. I plotted an a weiighted sunspot number vs time from 1770 to the present. The average sunspot was developed using weighting factors of .4, .3, .2 and .1 for the periods of 0-10, 10-20, 20-30 and 30-40 years before the date of the data point. The resulting plot is consistant with observed long term temperature trends. It would predict the rapid temperature increase of the past century.
  46. Is CO2 a pollutant?
    Suibhne, yes the G&T paper covers EM radiation (incorrectly) in subsequent sections. However, at the start they define a premise that rising CO2 can only be causing warming if it significantly changes the thermal conductivity of the atmosphere as a whole... and then go on for a few pages to show that it doesn't... but then no proponent of the greenhouse effect ever claimed it did because that's not how the greenhouse effect works and G&T are simply, in that section, ignoring radiation physics. In later sections, when they do discuss radiation, they incorrectly dismiss radiative transfer on the grounds that it doesn't conform to thermal conductivity... in essence repeating their original false premise. Again, show me something in their paper which proves that the greenhouse effect does not exist. You insist it is in there, but have repeatedly refused to cite it.
  47. Did Phil Jones really say global warming ended in 1995?
    theendisfar, please follow the comment policy: "No off topic comments. Stick to the subject at hand. If you have something to say about an unrelated topic, use the Search form in the left margin to find the appropriate page."
  48. Is CO2 a pollutant?
    suibhne, i didn't reply to your accuse to Smith on the air molecule behaviour because it's irrelevant to our discussion. Not sure what you are quoting. I assume it was this: "Molecules don't know what the local temperature is, so "hot" molecules happily travel from cold regions to hot ones, and vice versa." If you have followed the whole reasoning, he was contrasting single molecule behaviour with macroscopic "averages". In this sense, it's absolutely correct and does not violate any law of thermodynamics. Indeed, temperature itself is a thermodynamic quantity and can be properly defined only as an ensamble average. Let me quote from a good old book (Terrel L. Hill, "Statistical Thermodynamics", chapter 1, the very first paragraph): "The object of thermodynamics is to derive mathematical relations which connect different experimental properties of macroscopic systems in equilibrium - systems containing many molecules, of the order of, say, 10^20 or more. However useful, these interconnections of thermodynamics give us no information at all concerning the interpretation or explanation, on a molecular level, of the observed experimental properties." With this in mind, we can go one step further and easily see that there's no violation of any law of thermodynamics (as too often claimed in certain quarters) when a molecule radiate a photon toward a warm object simply because thermodynamics does not apply at the single molecule level. A molecule will not choose the direction of the emitted photon, it can not. Still, thermodynamics applies at the macroscopic level, or, in terms of statistical thermodynamics, to the ensamble averages of the mechanical or thermodynamic quantities. So it should come as no surprise that the net overall flux will always be in the right direction.
  49. Is CO2 a pollutant?
    Riccardo Point well made ..For this discussion to go anywhere you need to deal with the actual physics involved. I have to sign off as time presses. But what did you think of Smiths howler?- surely we can agree on that.
  50. Is CO2 a pollutant?
    CBDunkerson You imply by saying ... we must look at two factors; thermal conductivity and isochoric thermal diffusivity..that G&T do not deal with EM radiation. Most of their paper deals with em radiation! To selectively misquote and then prove a point will not further anyone's understanding.

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