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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 87601 to 87650:

  1. Cosmic ray contribution to global warming negligible
    rhj, and when you're outside on a clear, frosty morning do you notice the difference when cloud cover moves in? I notice that it gets a bit less nippy at those times.
  2. Cosmic ray contribution to global warming negligible
    I bought Svensmark’s book because I like to expose myself to both sides of an argument and I wanted to get the “best” of the pro-GCR side. When I pointed out to other readers (on Amazon) how biased the book’s review of scientific literature was I was truly amazed at how quickly I was “voted down” (I never even got into Calder’s (the real author) dubious history of scientific reporting). I admit that it is an interesting hypothesis, but only folks highly selectively biased by personal belief could possibly believe that galactic cosmic rays have a climate effect greater than that of the change we have seen in atmospheric CO2 levels. Little in the scientific literature supported it then and even less does now.
  3. A Convention for Persons Displaced by Climate Change
    Some attempt to quantify the number of Climate Change displaced (or migrating) people, ie, those displaced or migrating for environmental reasons that would not have been displaced or migrated were it not for climate change. The simplest and crudest way to make such an estimate is to eliminate population growth from the equation. World population is growing at just over 1% per year, with growth in even the fastest growing regions barely exceeding 2% a year. We can optimistically estimate population growth in environmentally degrading regions as being at 3% per annum, or 55.8% over 15 years, 142.7% over 30 years, and 408.2% over 55 years. With 25 million environmentally displaced in 1995, that would lead to an expectation of 39 million environmentally displaced by 2010; of 61 million environmentally displaced by 225; and of 127 million environmentally displaced by 2050. This compares to Myers predictions of 50, 100 and 200 million environmentally displaced for each of those years. That means he is predicting 28% more environmentally displaced in 2010 than can be accounted for by population growth alone, with 64% more in 2025, and 57% more in 2050. From the figures provided in posts above the 2010 prediction seems reasonably accurate, with the number or environmentally displaced people (including environmental migrants) being somewhere between 30 million and 80 million. That means that it is highly probable that a significant number of people have already been displaced by climate change. It is very probable that that number will grow in the future.
  4. A Convention for Persons Displaced by Climate Change
    HarryS #53: Clarifying: At #51, you suggested that three 'weather events' explain the severity of the current drought. I'm not so sure it's that easy. Point 1: Here's the rainfall total for Alex: That wasn't enough over Texas to do as you suggest. Point 3: The current drought began in October, not in the spring as your model stated. Recent drought history for the southern US shows significant areas of D4 'exceptional' in 2000, 2006-2007, 2009 and now 2010. Sure, there's no smoking gun to show that the latest exceptional drought is directly due to AGW; it is, however, yet another set of extreme events that fit right into the pattern. Seems like 'exceptional' isn't so unusual any more. Perhaps they need a D5 category - I suggest 'Biblical.' I suppose it could all be coincidence. But that's not much of a scientific argument.
  5. A Convention for Persons Displaced by Climate Change
    Adelady @49, I disagree on two counts. There are a very large number of displaced people in Somalia, but most of those have been displaced for some time due to conflict in Somalia so are not environmentally displaced. Also, in the case of drought it is very rare that all water stocks are exhausted, and aid agencies often supplement water supplies to a substantial extent. It is therefore very unlikely that all, or even most of the effected people will abandon their homes and lands. You will notice the source I linked quoted 52,000 as of 30 March. The number displaced has probably grown since then, but not 3000% percent.
  6. A Convention for Persons Displaced by Climate Change
    michael sweet @50, as I've probably made clear, I don't like the "refugees" terminology because, no matter how well defined and understood in academia, in normal use it is likely and has been misunderstood to indicate a much narrower group of people than Myers intended. This leads to people making unwarranted assertions about the impact of AGW, ie, that there will be 50 million people displaced by Global Warming by 2010 in good faith, whereas the actual prediction and figures support there being over 50 million displaced or migrated due to environmental degradation in 2010, including that caused by specific development projects. Nor do I consider the numbers I have quoted as in any way rigorous. Even the reports they come from do not consider them rigorous. What they are is indicative, and proof that those who just dismiss the idea of 50 million environmentally displaced people have made only laughable attempts to quantify the issue. So, I am quite happy for you to quote the figures I and Albatross turned up, you should always do so with the appropriate caveates. On a side note, a common meme is that Myers methodology was just to add up the populations of the effected areas. As the "effected areas" include China, India, Egypt, Bangladesh, and Pakistan (amongst many others), the population of the effected areas is over 2 billion people. Obviously the slander against Myers is simply ridiculous.
  7. Cosmic ray contribution to global warming negligible
    A few questions: "Forbush decreases (few percent decrease in cosmic ray flux that lasts few days) have been claimed to cause cloud cover changes." It's not clear what you're saying here: are these cloud cover decreases due to lower CR flux? Svensmark et al 2009 make this quixotic remark: We find that low clouds contain less liquid water following Forbush decreases, and for the most influential events the liquid water in the oceanic atmosphere can diminish by as much as 7% "In a recent analysis, it was found out that in mid-latitudes rapid changes in cloud cover are associated with changes in cosmic ray flux and in surface temperature." Who did this analysis? Again, which way are the changes? "the cosmic ray flux has decreased about 0.6% in last 50 years." Do they claim any significance to this decrease? Isn't this the best take-away? The contribution of CR to ‘climate change’ is quite negligible.
  8. Cosmic ray contribution to global warming negligible
    I suspect cloud formation has a major influence over our climate. Even the IPCC admitted that cloud formation is poorly understood. Cosmic rays may not be the main driver, but a deeper understanding of the mechanisms involved would surely be a significant step forward. If I simply stand outside and feel the difference between full sun, and cloud, and just feel the difference in energy reaching Earth's surface, I can't help thinking this is what it's all about.
  9. Harry Seaward at 09:02 AM on 24 April 2011
    A Convention for Persons Displaced by Climate Change
    Muon @ 52 I'm not sure of your point. It takes a while of little or no rain (basically below average) for a region to enter a drought state. Please clarify.
  10. A Flanner in the Works for Snow and Ice
    93, Alec Cowan,
    I know that you are making a personal effort to help those people to understand...
    Actually, no, not really. I mean, if a light bulb happens to go off over their head, fine, but no, that's not the point. I know the odds are one in a billion (and what I mostly want to do with someone like RW1 is to at least get him to stop posting his own gibberish and confusing others). I post comments mostly for the lurkers, for the thousands of people who only read and don't post comments. Some of those are as close-minded as the person posting (Ken, RW1), and out of reach. Some have made up their minds, but aren't as close-minded as it seems, and when the light goes on for them, even if it only plants the seed of doubt in their own position, something has been accomplished. Others are more on the fence, or even trusting of the science, but can begin to doubt the science if the trickery and distractions aren't laid bare for them. I well remember the days when I myself was mislead by "skeptic" arguments, and it took a lot of work and hours (by me) to realize that they were all smoke and mirrors. So I see nothing wrong with being up front, providing calculations, admitting to errors when I make them, and letting a conversation drag on for way, way longer than it should (a la RW1), because the point is not to "win the argument." The point is, instead, to demonstrate fallacious arguments, unsubstantiated claims, and an obstinate unwillingness to think and reason, although not to the person posting, but rather to others who are reading both sides of the debate. People with arbitrary or incoherent positions don't have to "admit defeat" to be exposed.
  11. Wakening the Kraken
    It's worth keeping in mind that the relative efficiency of methane as a greenhouse gas depends very much on its concentration. At modern concentrations, CH4 is molecule-for-molecule a better greenhouse gas than CO2 (say, if you increase methane from 2 to 3 ppm and CO2 from 390 to 391 ppm). This relative efficiency is very easy to work out using the Myhre et al 1998 table of radiative forcing (Table 3). For example, when comparing an increase of 1 to 2 ppm of methane vs. 389 to 390 ppm increase of CO2, the methane generates 30x more radiative forcing. But if you compare that methane change to a CO2 increase of 149 to 150 ppm, it is only 11x stronger. Methane too, can only be thought of as a powerful greenhouse gas because it is nearly in a logarithmic limit and you are starting from a low baseline concentration. If you were to compare the effects of two nitrogen/oxygen only (IR-transparent) atmospheres, but one with 100 ppm of CO2, and one with 100 ppm of methane, the CO2 atmosphere would generate more reduction in the outgoing radiation. This is because CO2 absorbs at wavelengths more well placed near the peak of the Planck function for a body at Earth-like temperatures. Thus, if that 100 ppm methane atmosphere was all oxidized into CO2 (and it stayed in the air), you would generate warming. The implication is that methane is not intrinsically a better greenhouse gas at all, it only looks more important in the current atmosphere when you compare a molecule-for-molecule increase between CH4 and CO2. This is important to keep in mind when looking at prospective greenhouses with relatively high abundances of methane.
  12. A Flanner in the Works for Snow and Ice
    @Sphaerica #93 You are doing it the same style as with RW1 in other posts. Don't provide your own calculation. I know that you are making a personal effort to help those people to understand, but they simply don't want to understand and the final result is negative. They present their own calculations and considerations, they tend to be more tight when they are criticizing one obvious mistake in the rival's, they tend to be sloppy when they have to introduce "their evidence" to contrast the post or the so-called "climate science". I mean they need all those numbers to pluck everything opposing their intended conclusions. The technique that Ken Lambert has used here is much more coarse and by following the path he proposes you are helping him to disguise his technique which includes criticism developed in the fringes of a reality-check calculation on part of one of the chosen rivals, taking what can be played down and/or declare a personal achievement(A), declaring the results out of scope or negligible (B) and distorting the line of argumentation just to jump to their chosen playfield using a variety of sub-techniques such as, but not limited to, telling that the rivals don't know what their talking about(C), affirming the they have the *real* (*=little cherubims) epistemological path to a proper answer -the twist starts there- (D) to finally -by using verbal lidocaine or the technique rod fishers use to wear out a fish- throwing a subdued admonition that point to dismiss methods and morals of the rival and start his own song starting with "I" (E) (Examples here) Sphaerica, this technique is not counteracted by an endless exchange of comments where one part continue to do bonafide calculations and reasonings and the other just try to constantly sneak their technique. You may think that you are doing well, and that can be true, but look what you are talking about and you will find that you where brought to a terrain chosen by them. The fact is that we'll probably have a couple of troubling months in front of us, as Washington & Cooke's book will be soon released and the publicity, be it little or be it huge, will drive here a lot of infuriated "skeptics" that will subscribe in dozens and attack in pack, so the episodes involving some Paul these days will be ten-folded. Those people will be counting on the toes and fros that I'm criticizing and you might be providing a culture medium if you and others spread to thin and continue to use reality checks as front row science and disregard counteracting the technique they use. Not only it is a huge waste of effort but it also promotes the idea of a sloppy climate science, exactly what the (so-called) "skeptics" pretend. From here: "I am glad your calculation agrees with mine that the effect of arctic ice melt is trivial (2.8% increase in arctic forcings since 1978)". A "What about the effects on the other 95.6% of the Earth's surface, like the 70% occupied by the oceans where we still can't find the absorbed heat". B From here: "What is your point in calculating the incoming and ignoring the outgoing?" C "Surely the whole discussion of AGW is about the *net* warming effects. One might as well suggest that we only look at possible changes incoming flux on *any* part of the Earth, while ignoring the changes in outgoing flux". D ("outgoing flux" and "cellar door", don't they sound charming?) From here: "Tom, wilfully leaving out relevant information of which you are aware simply is a distortion of the case to suit a particular bias". E
  13. Wakening the Kraken
    Sphaerica #17 My understanding of the issue seems right, then. It's only those Modtran figures that don't match. Maybe I'm failing to interpret its results properly. Ron #18 No, it's not the unit. Archer's Modtran uses ppm as well... Anyway, thanks for the responses.
  14. funglestrumpet at 06:48 AM on 24 April 2011
    Lindzen Illusion #1: We Should Have Seen More Warming
    Just a thought regarding bringing people into line who are thought to be deliberately making misleading statements. I can sympathise with the desire that academic freedom should not be made to suffer as a result of any control mechanism established to counter such behaviour, so how about the following? Establish an open email forum for making accusations of academic misdemeanours. (Only open to bona fide scientists specialising in the field i.e. established peers of the person who is the subject of the complaint). Whilst only an email rather than a formal letter, it should follow a strict code of practice, which the scientific community decide upon. This is then made available to view publicly on some dedicated web site. The ‘accused’ should then respond, explaining their position. There then follows a series of exchanges with supporting evidence until the matter is either resolved, or in need of arbitration. All correspondence is automatically open to view by anyone, so that they can see how the debate is going. I think the press might get some mileage out of this, thus raising the profile. There would be the need for checks and balances. For instance frivolous complaints should be subject to sanction (scientific community to decide on exactly what that should be). There would need to be an international administration (U.N.?) where records would be kept etc. And they should also be responsible for passing on emails from other interested parties (restricted to those operating in the field) so that all correspondence is of value to the debate i.e. a filtering process might be necessary. (This secondary correspondence should be kept private to the sender, recipient and arbitrators.) Serious thought would have to be given to the arbitration panel, perhaps even formed from the judiciary with the power to call on guidance from learned scientific personnel. Finally, the issue is resolved and if the case is found proven, some sanction (scientific community to decide – possible publication of findings on the public website set up for the purpose?) This is only my loose thoughts on the matter, please treat it as seed corn for discussion. To the moderator. There seems to be quite a lot of discussion on this topic. How about a separate thread with invitations to post from other scientific fields – it will impinge on them after all.
  15. A Convention for Persons Displaced by Climate Change
    Harry S#51: "Texas then entered the spring of 2011 in a drought situation " Records show this most recent Texas drought started in October 2010. So its not quite so cut and dry, so to speak.
  16. Wakening the Kraken
    Don't forget Alexandre that although methane concentrations in this article have been quoted as ppm you will more frequently see them referred to in ppb. Seeing that methane has risen from ~850 ppb in 1750 and now is at ~1800 ppb it's not likely that you'll see rises in concentrations of 1 ppm. So for the example you previously used in #11 a 1 ppb increase in methane would only be an increase of .471 W/m2 which when multiplied by 19.96 would equal your stated 9.4 W/m2 for a 1 ppm increase in CO2. That's fairly close to the 20 times the warming potential correct? Of course if it did rise by 1 ppm compared to 1 ppm CO2 then the warming potential would be 20,000 times that of CO2 (that would constitute a very very large input of methane to the atmosphere).
  17. Wakening the Kraken
    RE relative GHG "strength" of CH4 and CO2 I've looked into this before, and while I don't remember all of the particulars, you did already touch on the important factors, which are that residence time, absorption band, and other factors all come into play. Basically, the answer is that trying to come up with a single scalar value that represents "warming" potential for a substance is a fool's errand (well, not really a "fool's"... the task has value, but you have to understand the limitations of what you're trying to get). Certainly it matters what current levels are, and what they're changed to, in both gases you are comparing. Time frame matters. Current opacity at various wavelengths matter. So adding methane may be more powerful for the next ten years, for example, but not fifty years from now. Adding it to an already souped up CO2 atmosphere is more powerful than adding more CO2. Etc. In the end, I think a simple scalar rating like that is like trying to rate the fastest car in a race. Some cars accelerate better, some corner better, and some have a higher top speed. Some can stay in the race longer without a pit stop. You can't just say "car #23 is faster than #52" because it depends on the track, the conditions, and the length of the race.
  18. Wakening the Kraken
    5, James Wight,
    Wasn’t the Holocene Optimum caused by Milankovitch cycles?
    Yes. And no. Strong positive feedbacks (not methane in the current theory, I believe, but CO2... although I'm not that well read on it) are a major and necessary factor to the Holocene Optimum. Milankovitch cycles started it but are not of and by themselves sufficient to begin or end a glacial period. CO2 was necessary to complete the transition. To learn more search for "last glacial termination" on Google, and look for things like this paper: Denton et al (2010).
  19. Christy Crock #1: 1970s Cooling
    40, Alexandre, What I find even more frightening is that the human induced aerosols are helping us right now, by adding a strong negative forcing in concert with the positive forcing from CO2. The day we cut back on fossil fuel use, CO2 levels will still stay high for a century or more, both because of residence time, and because the ocean is becoming so saturated with it... any attempt by nature to reduce it in the atmosphere will simply result in nearly equal replacement from the ocean for quite some time. But aerosols will drop fairly quickly, and so that negative forcing will disappear, and temperatures will shoot up (or at worst continue to rise evenly but inexorably) even after fossil fuel use is reduced. We'll have to suffer through that further increase before the situation starts to stabilize. Not good. And yet Dr. Christy focused on misrepresenting this science from 35 years ago, rather than the complex and disquieting truth behind aerosols, both then and now.
  20. Christy Crock #1: 1970s Cooling
    I'm not sure if this has been enough stressed on the original post, but AFAIK the "cooling prediciotns" were based in good science. It's just that the scenarios of aerosol emissions never actually happened. So first, most of the studies by that time already projected warming. Second, the cooling papers did not deny the warming properties of GHG. And third, I don't think anyone would say the emission scenarios used today will not happen in a business as usual projection.
  21. A Flanner in the Works for Snow and Ice
    95, Ken, As Tom already pointed out, the annual average insolation in the Arctic is greatly influenced by the seasons, such as the 24 hour long sunless days through most of the winter. As I already said, the season we're talking about is at peak insolation when hours of daylight would be higher. Using the annual average is clearly wrong. This is a fairly obvious factor, and demonstrates a distinct lack of thought on your part. I also already used very conservative numbers for many other items, such as the change in albedo. Again, the impact to the climate of increasing summer Arctic ice melt will be anywhere from 0.67˚C to 1.3˚C. All other arguments are moot unless I've made a (real) mistake in my calculations. The question at hand has been whether or not the melting of summer ice in the Arctic will have any impact on climate. The proposal was that the increased positive albedo feedback would be significant. The argument was that the Arctic only covers 4.4% of the globe, so the feedback cannot be significant. The numbers show that the positive feedback is more than merely significant, but downright scary. Case closed.
  22. Harry Seaward at 01:03 AM on 24 April 2011
    A Convention for Persons Displaced by Climate Change
    Sweet @ 50 Three factors contributed to the Texas wildfires 1. Heavy rains from Hurricane Alex last summer caused a huge increase in biomass (plant blooming). 2. The winter of 2010-2011 was extremely cold and caused a massive die-off of plant life. 3. Texas then entered the spring of 2011 in a drought situation with March being the driest March in state history. Those 3 factors created a tinderbox situation that is fueling the fires. High winds and hot weather are exacerbating the situation. I suppose you could take those 3 factors and link them to AGW in some way and make a statement that these fires were caused by AGW. But, that is far different from using science to prove it. We can have a scientific discussion about this if you desire and are capable. This ain't handwaving and I'm no troll. This thread has meandered a bit between climate displacement and environmental displacement and the line between the two is a bit fuzzy. I believe that area-wise the current fires are greater in size than anything recorded. That alone can increase the effect impact to humans, however it must be considered too that the increasing population and building of homes in areas historically prone to wildfires have factored into financial losses. It is no different than building more and grander homes on beaches prone to being hit by hurricanes, or increasing human populations in areas prone to flooding like the Indus River in Pakistan.
  23. Wakening the Kraken
    Ron #14 Thanks, it does help. So the timescale for the 25 figure is indeed those 100 years. But I still don't understand that result I got with the Modtran. CH4 was just 50 times stronger there, and I assume it calculates just the immediate forcing, not averages over time. It should have shown something larger than that methane Global Warming Potential of 72 over 20 years I saw in your Wikipedia link. Am I still missing something?
  24. A Flanner in the Works for Snow and Ice
    Ken Lambert @91, in fact I do "get it", but you continue to ignore the relevant facts which allow me to get more than you will allow yourself to understand. Consider the cumulative incoming additional energy flux from ice albedo effects relative to 1979 for successive five year periods from 1979 to 2008: 1979-1983: -7.40E+020 Joules 1984-1988: -4.18E+020 Joules 1989-1993: 8.24E+020 Joules 1994-1998: 1.41E+021 Joules 1999-2003: 2.06E+021 Joules 2004-2008: 6.97E+021 Joules If you pay attention you will notice that for the first 10 years, the value is negative. In fact, for eleven of the first eighteen years between 1979 and 2008, the ice albedo effect was a negative feedback relative to 1979 levels (though a positive feedback if compared to 1950 levels). The reason for this is that 1979 set a new record for summer minimum ice extent, so natural variation took the ice extent above that record in a significant number of the following years. The most important consequence of that for this debate is that the cumulative increase in incoming flux relative to 1979 levels (ie, your chosen comparison period) does not become positive until 1995. In other words, the doubled figure which will only be "...2.8% of accumulated heat from 4.4% of the Earths surface area over the last 31 years of official AGW" will in fact only be accumulated energy over something less than 16 years. Further more, for most of those 16 years, the change in the summer accumulated energy flux was only small, with a 6*10^20 Joule increase in the 5 year accumulation. But the last five year period shows a 4.91*10^21 increase over the preceding years. That is nearly half the accumulated value for the thirty years in just the last five years! In fact 2007 alone accumulated more energy (2.54E+021 Joules) than any five year interval ending prior to 2005, and indeed, more than the 10 years from 1989-1998. 2008 (2.05E+021 Joules) is not far behind, and accumulated just 0.5% less energy than the five years from 1999-2003. Clearly the ice albedo effect was not such a big deal 20 odd years ago, but then again, nobody said it was. It is a big deal now. Thirty years accumulation at the average rate of the five years from 2004-2008 would accumulate 4.182*10^22 Joules. By your calculation that you say I don't get, that means it would constitute 5.6% of the Earth's accumulated energy. And that is with a figure very conservatively estimated, which ignores the additional energy gain in any season outside of summer, and in which three years of the five year average come from before the drastic 2007 reduction in summer sea ice. So what I get, but you plainly do not is that the ice albedo effect has gone from "ho hum" 15 years ago to a game breaker today. No matter what contortions you try, and no matter how much you want to include the low values of 30 years ago in your comparisons to mask the high values today, I will not forget this fact. And as clearly indicated in my point three @90 above, all indications indicate that it is going to get worse. In ten years time the ice albedo effect is likely to add 0.18 Watts/meter squared to the global energy imbalance (bringing its total effect relative to 1979 up to 0.24 Watts/meter squared. At that point, the 4.4% of the Earth you think is so trivial will be causing 22% of the total global warming. And that is significant.
  25. Wakening the Kraken
    Global warming potential Hope this helps you Alexandre. According to AR4 over 100 years methane has a warming potential of 25 times that of CO2 and 72 times that of CO2 over 20 years.
  26. Wakening the Kraken
    Wakening is hardly a strong enough word. Hydrates were always considered a 'drilling hazard' and oil companies were required to do a site survey to show that a proposed well would not encounter any deposits. They've been considered the 'fuel of the future' for quite some time, but the risk/economics weren't favorable. Now that's changed and we're poking 'em with a sharp stick: Results from DOE Expedition Confirm Existence of Resource-Quality Gas Hydrate in Gulf of Mexico: A series of test wells in >6000' of water found what may be significant quantities of recoverable methane in hydrate deposits. Make that two sharp sticks: Combine drilling into an unstable substance in deep water, where you are entirely dependent on those subsea BOPs should something go wrong. Exploration of methane hydrate and assessment of resources: A summary of Japan's exploration program for hydrates; a more technical report available here (large pdf). They've apparently made at least one commercial discovery.
  27. A Flanner in the Works for Snow and Ice
    Ken Lambert @95, the annual average for the arctic is indeed just over 50 w/m^2, so Sphaerica ought indeed to divide by three. But then he ought also to multiply by four to eliminate the seasonal parameter he introduced, seeing as how he would be using an annual average. Why is it, I wonder, that you never notice errors or adjustments that favour your argument, but always notice any regardless of their merit, that are not favourable to your argument?
  28. Wakening the Kraken
    Alexandre, "But that's not 20~30 times either, so maybe someone more knowledgeble can help us understand how that number is calculated." The 30 times figure is arrived at as follows: X = the reduction in outgoing longwave radiation if the concentration of CH4 increases from its present level of 2ppm to 3ppm. Y = the reduction in outgoing longwave radiation if the concentration of CO2 increases from its present level of 380ppm to 381ppm. X = 30Y The reason for this is that the curve is much steeper at low concentrations than at high concentrations because at high concentrations the absorption bands are saturated. Here is my reference: http://chriscolose.wordpress.com/2008/11/10/methane-and-co2/
  29. A Flanner in the Works for Snow and Ice
    sphaerica According to #73 the Arctic averages about 50 W/sq.m so you had better start by dividing everything by 3.
  30. Wakening the Kraken
    Byron Smith at 22:00 PM on 23 April, 2011 According to Modtran, 1 extra ppm of CO2 traps 9.4mW/m2, whereas 1 extra ppm of CH4 would trap 471mW/m2. That's 50x more, so I'd say the 100 figure can be discarded. But that's not 20~30 times either, so maybe someone more knowledgeble can help us understand how that number is calculated. Probably it's the CH4 degrading to CO2 you've already mentioned - over a longer timescale it averages out to a smaller number. Would that timescale be one century?
  31. A Flanner in the Works for Snow and Ice
    Adelady If that be the case then you have missed the point of this whole exchange between Tom Curtis and me. It is about the extra heat absorbed from the Sun in the Arctic due to decreased albedo from reduced ice coverage. Heat transported from elsewhere is an internal effect - not an external forcing. ie. it is warmer in the Arctic but cooler where the heat originated giving no net overall warming.
  32. CO2 Reductions Will Not Cool the Planet? We Know
    Good letter Alan. Has inspired me to write more myself.
  33. Wakening the Kraken
    AFAIK, methane is some 20-30 times stronger than CO2 at present concentrantions, not 100+ times. It depends on the time frame used, since CH4 degrades to CO2. In shorter time frames, I have heard the 100x figure quoted. I note that the main article says "on a century timescale".
  34. Upcoming book: Climate Change Denial by Haydn Washington and John Cook
    Just to let you know - my copy of "Climate Change Denial" arrived in the post today. Having skimmed it, it looks a really good read, and Earthscan have done their usual good job on the production ...
  35. Wakening the Kraken
    Excellent but terrifying article. Thanks for bringing together lots of different research and painting the bigger picture. A couple of points: 1: We've already raised the atmospheric concentration of greenhouse gases enough to cause over 2°C of global warming from fast feedbacks alone. We can't rely on short-term anthropogenic aerosol cooling to save us from that... and given the positive feedbacks we're already seeing from just 0.8°C of warming, it seems wildly improbable to me that 2°C won't be enough to trigger carbon cycle and albedo feedbacks which take the warming completely out of our hands. 2: Where the article says "...total human greenhouse gas emissions (including CO2) since 1750 amount to some 350 billion tons", is that figure measured in tons of carbon or tons of carbon dioxide? I think probably the former, as CDIAC says that we've put about 1.2 trillion tons of CO2 into the atmosphere since 1750, of which around half remains, with the rest being absorbed by natural carbon sinks.
  36. Wakening the Kraken
    Artful Dodger at 16:02 PM on 23 April, 2011 Your data does not match my (limited) knowledge. AFAIK, methane is some 20-30 times stronger than CO2 at present concentrantions, not 100+ times. (like the main post and Wikipedia say). Yes, CH4 has a different absorption band than CO2 (which gives it all this GH potential), but the CO2 saturation argument dos not depend on CH4 emissions to be dismissed. Although CO2 cannot absorb any additional IR at 14um, it continues to increase absorption at wavelengths further and further away from this central frequency. (although, yes, with ever diminishing marginal impact per ppm added) Your last point is an interesting one. Could you please explain the math used? Or maybe point to a reference?
  37. Lindzen Illusion #1: We Should Have Seen More Warming
    #79 SB I think it is fairly obvious that stricter ethical guidelines should be enforced. Not at all to silence scientists, but to make them clearly state when they are speaking as experts commanding public trust, and when they are not. And when they are sure about what they are saying, and when they are not. And the principle I mentioned, that what they say should stand up to peer review, modulo popularizations, is really simple. It also underscores the inherent degree of subjectivity in scientific judgments: Several referees may all come to different conclusions, but more often they tend to agree. When there has been a complaint, and the referees' judgment is clear: This scientist has, as an expert in the actual field, said something in public that would never have passed review if stated in a paper, a warning may be issued. And repeated violations could lead to firing etc. In the actual case of Lindzen, he would probably have been out by now by such rules. He could save himself by a number of measures, some examples: 1. Stating that this is about climate science, and he is a meteorologist, so he isn't really an expert in the actual field. 2. Acknowledging that there are empirically well-founded approaches leading to apparently correct predictions, but noting that he himself thinks the modeling should be done differently. 3. Stating clearly that he uses the models in a non-standard way, so discrepancies must be expected. 4. Pointing to weaknesses or inconsistencies in the work he criticizes, reducing its validity. In this case, he is entitled to state that in public, provided he can back it up scientifically.
  38. Wakening the Kraken
    Typo: temeparture/pressure Normally I'd thank you for this piece, but I'm very much in denial over this one. :-(
  39. Lindzen Illusion #1: We Should Have Seen More Warming
    rhjames: what, all three of them? :-P But seriously, you need to go to the right thread to discuss the accuracy of the IPCC reports. [mods feel free to delete this post as off-topic]
  40. 2nd law of thermodynamics contradicts greenhouse theory
    Tom Curtis 1008 You asked: Given these clarifications, does your answer change, and if yes, to what? Unless I'm missing something, and assuming the constraints as outlined, the temperature for both plates is solely based on heating element....303K You said: The simple answer is that if Surface radiation goes above 2*S, or AtmUp, or AtmDn goes above S, then the system losses more energy than it gains, and therefore cools. I suspect we're arguing semantics, but how is that gaining energy cools? If Atm_up and Atm _dn are components of the an equally divided surface radiation, there is no cooling nor a decrease in entropy. The challenge for the alarmist is to find any partition of the system such that conservation of energy is maintained for that partition, and such that the Entropy decreases for that partition. That is, the partition must show an energy flow from E1 to E2 such that E1 = E2, but such that the Entropy of E1 is greater than that of E2. As an example, we have: 1) Insolation + Back radiation => surface radiation I said you said: You said equilibrium will be reached without back radiation being absorbed. Well, first note that in this model there must be back radiation because the "atmosphere" has an emissivity of 1 in IR wavelengths. Tom, do you agree equilibrium is reached WITHOUT back radiation? That is, with surface emission = 240 W/m^2 and only 240 W/m^2 (no additional back radiation) will system equilibrium be reached? Notice I'm not arguing the validity of forcing, at this point, but rather is equilibrium less forcing. So again, do you agree equilibrium is reached WITHOUT back radiation? You said: “With respect to the idealized greenhouse model it is the next step in complexity of atmospheric models from a simple grey slab model. It is still inaccurate...” Can you point me to the least flawed model. Not flippant or snide, but seriously...what is the best (least flawed) atmospheric model?
  41. Artful Dodger at 16:02 PM on 23 April 2011
    Wakening the Kraken
    Nice work. Here's a couple of additional points on Methane (CH4): * Since CH4 is at least 100x more potent as a GHG than C02, the effect of CH4+C02 is the same as 570 ppm CO2 concentration. * CH4 has a different absorption spectra than C02, and captures outgoing radiation in wavelengths where C02 is transparent (the C02 Window). * CH4 is one of the main reasons why the 'CO2 effect is saturated' mime is irrelevant to discussions of Global Warming: releasing CO2 causes warming which causes the release of CH4. * the abundance of Methane Clathrates exceeds that of atmospheric carbon by a factor of two. Over a hundred year time frame, CH4 decomposing to CO2 could take CO2 levels to 1,200 ppm WITHOUT us burning any more fossil fuels.
  42. michael sweet at 15:49 PM on 23 April 2011
    A Convention for Persons Displaced by Climate Change
    Tom: You have found close to or above 50 million refugees in 2008 alone. With the Pakistan floods 2010 must be similar. The total for 2008-2010 would be twice what Meyers estimated, or more. It seems that your actual numbers have quieted the trolls. If they had any real data to discuss, and not just hand waving and doubt, they would come on again. I note the lack of data from them concerning the Texas wildfires. I do not expect to see them again here. Thanks for your numbers. They will be a good resource to refer to in the future.
  43. Wakening the Kraken
    “Evidence supports the theory that sudden and massive releases of greenhouse gases, including methane, caused decade-scale climate changes - with consequent species extinctions - culminating in the Holocene Thermal Optimum.” Wasn’t the Holocene Optimum caused by Milankovitch cycles?
  44. Wakening the Kraken
    Poem from 1830 The Kraken by Alfred Tennyson Below the thunders of the upper deep; Far far beneath in the abysmal sea, His ancient, dreamless, uninvaded sleep The Kraken sleepeth: faintest sunlights flee About his shadowy sides; above him swell Huge sponges of millennial growth and height; And far away into the sickly light, From many a wondrous grot and secret cell Unnumber'd and enormous polypi Winnow with giant arms the slumbering green. There hath he lain for ages, and will lie Battening upon huge seaworms in his sleep, Until the latter fire shall heat the deep; Then once by man and angels to be seen, In roaring he shall rise and on the surface die.
  45. Wakening the Kraken
    Great name for the chemical monster about to awaken. Finally we get a suitable name for an ogre greater than any myth or movie could ever deliver. http://en.wikipedia.org/wiki/Kraken http://en.wikipedia.org/wiki/Kraken_in_popular_culture
  46. Wakening the Kraken
    And we can’t expect the negative weathering feedback to save us, because it takes 100,000 years.
  47. A Flanner in the Works for Snow and Ice
    91, Ken Lambert, Sunlight reaching the surface of the earth equates to about an average of 184 W/m2. For 4.4% of the earth's surface, this equates to 184 * .044 = 8.096 W/m2. If the albedo change is from ice (.9 albedo) to open water (.1 albedo), or a change in absorption of 0.8, then 8.096 W/m2 * 0.8 = 6.4768 W/m2. If this change only applies to 3 months out of the year (1/4), that's 6.4768 W/m2 / 4 = 1.6192 W/m2. This does not multiply the number by any factor to account for the fact that the area is under 20-24 hours of high-incidence insolation per day. A forcing of 1.6192 W/m2 is close to one half of the 3.7 W/m2 forcing caused directly by CO2, which would itself cause 1˚C of climate change, and a total of 3˚C with feedbacks. Since those same feedbacks operate regardless of the forcing, we can assume a warming rate of 3˚C / 3.7 W/m2. For our high conservative estimate of 1.6192 W/m2, this translates to an additional warming of 1.3˚C. One could argue that the change in albedo from sea ice (.7 albedo) to open water would be only 0.6, and that the entire Arctic will never (?) melt for an entire 3 month span, so let's make another estimate of only 3% of the earth's surface, and an albedo change of only 0.6, giving 184 W/m2 * 0.03 (%surface) * 0.6 albedo * (1/4 yr) * 3˚C / 3.7 W/m2 = 0.67˚C So with a very conservative estimate, 0.67˚C is still very far from inconsequential when it is being added to other warming that is already at dangerous levels. [Admittedly, this is sort of double counting, since this feedback is already included in the estimated 3˚C of warming from the original 3.7 W/m2 of doubled CO2 forcing. But the point is still the same. This value is not insignificant.] Oh, and please certainly check my math, and my logic. I certainly could have made an error in there.
  48. A Flanner in the Works for Snow and Ice
    Ken, "Unless heat is transported to the Arctic from elsewhere on the planet ..." Until the last couple of decades, this was the *only* way for heat to affect the Arctic substantially - it's the major source of the heat that has melted the ice so far.
  49. Lindzen Illusion #1: We Should Have Seen More Warming
    JMurphy - you challenge me to point out incompetence of the IPCC. I doubt you are serious - it's been well documented before, and to go into detail here would be off topic. They have even admitted publicly to many of their errors.
  50. Lindzen Illusion #1: We Should Have Seen More Warming
    Peter said... "All other environmental issues, pollution, over foresting, over fishing, decertification, clean water and ocean destruction have fallen off the table thanks entirely to 'climate science.'" Hmmm, seems that Peter is unfamiliar with the massive amounts of environmental damage which are attributable to the extraction & combustion of fossil fuels-even if you completely ignore global warming. Mining of fossil fuels consumes large amounts of land & water-& frequently leads to contamination of both with toxic by-products. The combustion of coal produces significant amounts of air pollution-such as particulate emissions, as well as cadmium, mercury & radon gas. Combustion of petrol & diesel fuel also produces particulate emissions, along with benzene & nitrogen dioxide. A tendency to rely on raw over recycled materials-which also contributes to increased GHG emissions-is also a source of increased landfill size & resultant pollution. So actually, dealing with the various causes of global warming will have the effect of dealing with *all* of the environmental issues that Peter Wells lists as important. Of course, I could add that, even were this not the case, the last I checked humans were capable of "walking & chewing gum at the same time". To suggest that dealing with climate change somehow makes us incapable of dealing with other social & environmental issues is just another typical straw-man argument.

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