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Comments 69251 to 69300:

69251. RW1 at 11:08 AM on 16 December 2011
       2nd law of thermodynamics contradicts greenhouse theory
       I can't believe this thread now is 1200 posts! There is no violation of the second law with the Greenhouse Effect, because it's not about energy going from cold to warm through a conduction process. Does anyone actually think that a re-emitted photon cannot travel from the colder atmosphere toward the warmer surface? How do the photons from the Sun pass through the colder upper atmosphere and reach the warmer surface?
69252. alan_marshall at 10:39 AM on 16 December 2011
       The End of the Hothouse
       If a drop in CO2 down to 600-700 ppm caused the onset of Antarctic glaciation, that is additional evidence we can use to rebut the skeptic’s argument that the CO2 effect is saturated.
69253. John Hartz at 10:21 AM on 16 December 2011
       (Fahrenheit) 451 ppm
       DB I believe when someone like "skept fr" is allowed to hi-jack a comment thread, it turns off other readers and inhibits their active particpation in the comment thread.
69254. skywatcher at 10:05 AM on 16 December 2011
       Climate sensitivity is low
       Richard Arrett, among many other problems, you're ignoring the possibility that more than 100% of the warming since 1950 is due to CO2. Impossible! I hear you cry. But not, actually, as it is quite likely that aerosols are offsetting the non-CO2 warming effects and some of the CO2 warming effects. It will be "interesting" in a Chinese curse sort of a way, when China and India sort out their pollution issues. Another issue is you keep discussing equilibrium sensitivity values when you should be discussing transient sensitivity values, which are closer to 2C per doubling. We don't expect to see equilibrium sensitivity-sized changes instantaneously.
69255. pbjamm at 09:36 AM on 16 December 2011
       2nd law of thermodynamics contradicts greenhouse theory
       I genuinely have no idea what any of this has to do with violations of the 2nd Law of Thermodynamics.
69256. TOP at 09:27 AM on 16 December 2011
       2nd law of thermodynamics contradicts greenhouse theory
       @1197 Sphaerica I think I just answered part of that in 1198. In the Wood (1909) experiment, there was a small discrepancy in how fast the two boxes heated. The box with the IR transparent cover heated faster. So I jumped to the conclusion that if that was so, and if placing an IR opaque filter in front of the box caused the temperature rise to drop, then the same would be true if the atmosphere were IR opaque (which it isn't, see muon's charts.)
69257. TOP at 09:19 AM on 16 December 2011
       2nd law of thermodynamics contradicts greenhouse theory
       @1163, 1193 scadenp Well, I thought I did in 1174, but Philippe in 1179 pointed out that I incorrectly used the term energy for "Sunlight". It just all depends on what Blambda means when integrated as in equation 30 on page 22. It could just be power (energy per unit time) integrated over a portion of the spectrum. [I am being a bit imprecise here. You can look up Blambda elsewhere.] That table in G&T is referring to the black body radiation of the sun before it passes through the atmosphere. So of course the gases in the atmosphere are going to take their "cut" of the radiant energy on the way down. Wood demonstrated, however, that a significant and measurable portion of IR does in fact reach the ground. But muon's charts support this finding. Just out of pure curiosity, how does RGHE deal with the warming of CO₂ from the sunlight? And why does muon's graph show such a low temperature in the CO₂ notch looking down from above if there is so much radiant energy available to heat it? I have a thought on that but I am wondering what your opinion is.
69258. Richard Arrett at 09:18 AM on 16 December 2011
       Climate sensitivity is low
       John Russell at 04:50 AM on 16 December, 2011: I certainly did not feel like I was being banned. I am moving to this thread so as to not be off topic. The warming since 1950 has been around 1 degree F or .55 degrees C. But how much of that is due to CO2? I read 75% in one article and 50% in another. Lets say 75% of the warming from 1950 is due to CO2 and the rest is due to land use changes, black carbon on snow, methane, etc. So .75 degrees F seems like a fair estimate of the warming from 1950 caused by CO2. First off - does that seem about right to you? I am not a climate scientist - so what I see from this data is that we seem to be on target for about the amount of warming you would expect from physics - but just the direct warming - no amplification effect. Doesn't that imply about 1.5 degrees F of warming to 2100 (or about .83C) from just CO2. Of course, there would be temperature increase also due to the other 25% non-carbon causes. If you just extend the trend line - doesn't it look like we will get about 1.2 degrees C by 2100? When I look at the data, I see the direct warming from CO2 - but no indirect warming from CO2. That is my main problem with a CS of 3 degrees C - it just doesn't add up for me.
69259. Bob Lacatena at 09:11 AM on 16 December 2011
       2nd law of thermodynamics contradicts greenhouse theory
       TOP, You still have not answered the question "How can an IR-opaque atmosphere possibly lead to global cooling?" I only ask again (for the third time) because I think that this may be at the heart of at least some of your problems. If you believe this, then there is something seriously wrong with your understanding of the physics involved. Please explain yourself.
69260. scaddenp at 08:58 AM on 16 December 2011
       2nd law of thermodynamics contradicts greenhouse theory
       TOP - we have no problem with idea that greenhouse effect is badly named. Its just not news. This in no way invalidates the fact the atmospheric greenhouse gases warm the planets. That IS the only point of substance for climate. SoD assumed G&T just skipped 100 years of literature; I think it more likely that they were trying to sow seeds of doubt about GHE with that long preamble. Looks like it worked. Are you arguing that IPCC science doesnt understand GHE. (eg as described here). Or that Ramanathan and Coakley 1978 (the basis for current calculations) have got it wrong?
69261. Daniel Bailey at 08:41 AM on 16 December 2011
       (Fahrenheit) 451 ppm
       John, I respectfully must side with KR on this issue. Shocking, I know (not the agreeing with KR part). Part and parcel of the "engaging the denial to debunk it" is not the actual attempted conversion of the fake-skeptic; the larger victory is the point-by-point takedown of the meme itself for the purposes of educating the many who read SkS, but will never comment in these threads (which they are under no obligation to do). Elucidate, educate and edificate.
69262. TOP at 08:34 AM on 16 December 2011
       2nd law of thermodynamics contradicts greenhouse theory
       @1192 pbjamm It isn't semantics. The good BBC professor purported to demonstrate the "radiative greenhouse effect" by comparing temperatures in a) a bottle filled with air (0.04% CO₂) and b) a bottle filled with CO₂. The experiment did not demonstrate what was purported even a little. Nor did it invalidate Wood's experiment in 1909. You have read G&T haven't you? They have a big problem with the term "greenhouse effect", if for no other reason than it is not well defined, at least for a mathematical physicist's purposes and it is not an "effect". There are 14 subsections in their paper that find flaws in published definitions of the term in, I would hope, respected literature on AGW. G&T are arguing the "semantics" because without defining terms, what exactly is being discussed? What I say is of little consequence. And just a note of style, if you quote, put it in quotes or indent. As everyone knows, I am easily confused.
69263. KR at 08:13 AM on 16 December 2011
       (Fahrenheit) 451 ppm
       John Hartz - I will point out that debunking anti-science propaganda is one of the purposes of the SkS site.
69264. muoncounter at 08:11 AM on 16 December 2011
       2nd law of thermodynamics contradicts greenhouse theory
       Wow, almost 1200 comments in and we have consensus: It shouldn't be called the greenhouse effect because 'real greenhouses don't work that way.' In what way do these pedantics change the physical science involved - or the outcome? TOP#1187: Very insightful critiques. Now do the same with your 'I measured the temp of the stratosphere with my handheld IR thermometer experiment.'
69265. John Hartz at 08:06 AM on 16 December 2011
       (Fahrenheit) 451 ppm
       KR: We are engaged in a propoganda war with a well-financed and sophisticated, international Climate Denial Machine. In my opinion, SkS is not obligated to provide deniers with a forum for posting anti-science propoganda.
69266. muoncounter at 08:05 AM on 16 December 2011
       Isn't global warming just 2 °C and isn't that really small?
       dagold: Watch this video from the recent AGU conference: Hansen, Rohling and Caldeira on the Paleo Climate record. Very informative on the evidence showing a record that dovetails with calculated/modeled sensitivities. Very sobering stuff on rapid changes, especially in terms of sea level.
69267. scaddenp at 07:54 AM on 16 December 2011
       2nd law of thermodynamics contradicts greenhouse theory
       TOP - as has been said before, great hunks of G&T are telling us what everyone knows full well but possibly they and definitely you, seem to think contradicts how we understand atmospheric physics to work. The skeptic point to take down in their paper was their idea that 2nd law is being violated. It is not. Muon has pointed you at the spectral observations from both top and looking up. Both agree with model calculations which could not be valid if G&T were right. There is no observational evidence to contradict the GHE and a very great deal to validate it. Now, have you figured out what was wrong with the G&T statement I quoted earlier?
69268. pbjamm at 07:53 AM on 16 December 2011
       2nd law of thermodynamics contradicts greenhouse theory
       TOP@1191: I do have a problem with calling it proof of the "radiative greenhouse effect" as applied to real greenhouses when real greenhouses don't typically have a 90% CO2 atmosphere ======= Is this a purely semantic argument that 'greenhouse effect' is an inaccurate description? At this point I am not clear what you are arguing for or against.
69269. TOP at 07:48 AM on 16 December 2011
       2nd law of thermodynamics contradicts greenhouse theory
       1189 pbjamm Read my response. I don't have a problem with the science. CO₂ does absorb IR. Look at muon's graphs and many others posted here. Those are actual measurements taken with expensive instruments. I do have a problem with calling it proof of the "radiative greenhouse effect" as applied to real greenhouses when real greenhouses don't typically have a 90% CO₂ atmosphere. Perhaps that experiment should be called the "absorptive greenhouse effect". Mr. Wizard did a much better job of controlling his 6th grade experiments in the '60s.
69270. scaddenp at 07:45 AM on 16 December 2011
       It hasn't warmed since 1998
       SirNubwub, you can get a clearer picture of what is really going on if you remove known sources of natural variation from the temperature as was done in this paper. Corrected graphs look like Not much sign of "global warming" stopping there is there? What do you figure will happen to temperature records in the next El Nino? Now perhaps you think that El Nino event will suddenly stop, but then perhaps you note that 2011 was hottest ever year with a La Nina event.
69271. TOP at 07:37 AM on 16 December 2011
       2nd law of thermodynamics contradicts greenhouse theory
       @1185 John Hartz This is a discussion about G&T. Their paper is long and I saw little specific discussion of the points that they made that could be traced to specific parts of that paper. So I quote it. Frankly I don't think that a lot of the discussion on this whole thread has attempted to address G&T. And even when quoting G&T the discussion seemed to diverge from the topic of the post rather rapidly. I will say that I haven't found much of anything in the respondents to my comments here that convince me of the error of G&T's ways. I learn a lot but I see a lot of regurgitation of information found in other papers and books. Most of it just comes down on me for word choice or "rhetoric". Guess I'll have to take remedial English or writing. But then this is a blog and I would expect to be cut some slack on form and style like I cut slack for others. And if banning me is the only way to win the argument that speaks loads for the argument. G&T have made some headway. In 1184 KR uses the term "radiative greenhouse effect" which to me is acceptable in place of the "convective greenhouse effect" which is what happens in real greenhouses. And I will note that G&T wanted to use the term "atmosphere effect" in place of "greenhouse effect" when talking about warming the atmosphere by radiation.
69272. pbjamm at 07:34 AM on 16 December 2011
       2nd law of thermodynamics contradicts greenhouse theory
       TOP@1187 "There was no control, no Design of Experiment and no statistically relevant reduction of data. This was just a snake oil presentation." Are you serious? This was not a graduate thesis, this was a 6th grade level science demonstration. If you really want to *prove* that it is fabricated nonsense perform the experiment yourself. It should not take more than an hour start to finish and you probably have everything you need in our kitchen. Please post a youtube link when you are done. I eagerly await your results.
69273. scaddenp at 07:29 AM on 16 December 2011
       Climate sensitivity is low
       jmorpuss, none of those links give any hint of any way by which the phenomena discussed could have any material effect on climate - by orders of magnitude. As such I cannot see how you can link this in any way to the idea that climate sensitivity is low.
69274. dagold at 07:20 AM on 16 December 2011
       Isn't global warming just 2 °C and isn't that really small?
       question...many of the news stories re: Hansen's recent statement that 2 C warming is, in fact, much more problematic than previously thought- have this quote-.."Hansen found that global mean temperatures during the Eemian period, which began about 130,000 years ago and lasted about 15,000 years, were less than 1 degree Celsius warmer than today. If temperatures were to rise 2 degrees Celsius over pre-industrial times, global mean temperature would far exceed that of the Eemian" My question: if the Eemian was about about (a bit less) 1 C warmer than 'today', wouldn't "2 C rise over pre-industrial times" bring our mean temp more or less EQUAL (maybe .2-.4 higher taking 0.8 C as present rise since pre-industrial) with Eemian and NOT "far exceeding Eemian"?? I am writing a book (very much accepting the consensus of climate scientists) on Climate Ch. from a layperson's perspective and I want to be as accurate as possible. Thanks!
69275. imthedragn at 07:16 AM on 16 December 2011
       Newcomers, Start Here
       scaddenp - part 2 is dead on what I was looking for. For now I will use the wikipedia source for 4,000 ppm average for water vapor. It also appears by rough estimate that over 90 of the water vapor is in the part of the troposphere containing 50% of the CO2.
69276. Bob Loblaw at 07:02 AM on 16 December 2011
       It hasn't warmed since 1998
       Re: SirNubWub What exactly do you mean by the phrase "global warming has stopped"? More specifically, what exactly do you mean by "global warming"? There are many measures of the temperature of the planet: - near-surface air temperatures over land (i.e., typical weather station data) - tropospheric temperatures from satellites or radiosondes - sea surface temperatures - deeper ocean temperatures At any time, one or more of these can decrease for a period, even if overall heat content is still rising. Examples would be the redistribution of heat related to ENSO. At any time, there may be temporary decreases in one or more of these, due to such factors as volcanic eruptions, anthropogenic aerosols, solar output, etc. The effect of the top-of-atmosphere radiation imbalance caused by increased atmospheric CO₂ leads to increased energy retention somewhere in the earth-atmosphere system, but it doesn't mean that every temperature, everywhere is constantly increasing. The implication of most "global warming has stopped" statements from deniers is to claim "global heating due to CO₂ has stopped", in an attempt to discredit the strong science that tells us the effects of adding CO₂ to the atmosphere. This implication is unjustified, misleading, deceptive, disingenuous, illogical, specious, unfounded, unscientific [insert favourite synonym here]. To make an analogy, the "global warming has stopped" claims are pretty much equivalent to claiming that the furnace in my house has stopped heating because I opened a window on a cold winter day and one room's temperature has dropped. The furnace is still pumping just as much heat into the system, and temporary, localized effects that show cooling don't change what the furnace is doing. You don't conclude the furnace is broken, when you know that the temporary/local cooling is caused by the open window. The effects of a volcanic eruption can be seen in a short-term temperature record. The effects of ENSO can be seen in a short-term temperature record. The effects of a short-term change in solar output can be seen in a short-term temperature record. The effects of a slow, steady imbalance due to rising atmospheric CO₂ cannot be seen in a short-term temperature record, and that means that short-term records also cannot show that the effect isn't there. It is an obfuscation by deniers to pretend that short-term variations in an global temperature record disprove greenhouse gas theory. To detect that slow, steady signal in the noise, you need longer records. Long enough to be statistically significant.
69277. TOP at 06:56 AM on 16 December 2011
       2nd law of thermodynamics contradicts greenhouse theory
       @1186 Tom Curtis Thank you Tom. I am trying real hard to make a reasoned point in a tough forum.
69278. TOP at 06:33 AM on 16 December 2011
       2nd law of thermodynamics contradicts greenhouse theory
       @1171 Moderator I viewed the BBC experiment. Thanks for the notes. Among other problems: 1. Lights repositioned between 1:14 and 1:18 so that the CO₂ light is more direct. 2. No control over the positioning of the lights. 3. The left bottle had .04% by volume CO₂ while the right bottle probably had 90% by volume CO₂ proving that CO₂ absorbs more IR than air if the experiment actually represented equal impingement of IR on the bottles. All this would prove is that CO₂ absorbs IR which nobody is disputing or perhaps that it takes an almost pure CO₂ atmosphere to raise the temperature a few degrees. 4. The right bottle had an object behind it that may have reflected energy back into the bottle. 5. There was no control, no Design of Experiment and no statistically relevant reduction of data. This was just a snake oil presentation. This experiment simply proves, if anything, that CO₂ absorbs IR, it has nothing to do with explaining why greenhouses warm in the sun. (-snip-).
       Response:

       [DB] Moderation complaints snipped.

69279. skept.fr at 06:19 AM on 16 December 2011
       (Fahrenheit) 451 ppm
       #96 Sphaerica : "You continually present a false dichotomy. You require a choice of either "abandon fossil fuels 100% immediately" or "stay on fossil fuels until the entire world is safe from poverty." Wrong. I observe how humanity behave (in energy-climate question) and try to understand why. If you consider the nearly 10 PgC/y emission in 2010 as a problem, you cannot just treat this problem by its future consequences, but you're obliged to discuss its present causes. I don't understand why such a simple idea is problematic here. At least, I understand it is a bit OT, but your reactions are not on this ground. Sea after, answers to Tom are relevant for your point. #97 Tom Curtis : The question is, then, will you withdraw your objection to the 2 degree C guard rail as a reasonable basis of discussion? Or will you instead show by your intransigence that when the science is against you, you just ignore it? Of course 2 K is a reasonable basis of discussion! And even the 350ppm Hansen target is to be discussed. But a) a basis of discussion is not a dogma in policy affairs ; b) as you say, science advises policymakers but does not replace them (happily, unless you dream of kind of 'expert government' where the diversity of human values, beliefs, convictions and consequently policy goals is ignored) ; c) if a basis of discusion is not sustainable, it will be abandoned after having losen a precious time in the wrong direction, and you gave me zero argument for suggesting this basis is sustainable (whereas I put at several moment some orders of magnitude for local (eg Indian) or global energy needs, potentially non compatible with the basis of discussion) ; d) you have totally ignore my major points, notably my 8-points response about my supposed "caveats" in #91 and after my different questions in #95. Such avoidance is sad for me, I've done the best to answer your own arguments against my case ; e) I consider (without any amenity) neither you nor Sphaerica offered convincing argument when you're questioned about the dilemmas between present problems / future problems solutions. I suggest you must have a reflexion on that because it is an argumentative weakness when advocating climate mitigation strategy, and will be more and more in the coming years. #98 John Hartz : Don't know, if there are rules for the number of posts in a discussion, please indicate them to me and I'll respect this number. Anyway I suggest to stop here this endless debate, I'm really tired of it. (-snip-)
       Response:

       [DB] Argumentative snipped.  Let's all rein in all points not specifically germane to the topic of the OP of this thread.  This has descended to the point of "Yes it is" and "No it's not" and detracts from the dialogue on this thread.

69280. Rob Honeycutt at 06:03 AM on 16 December 2011
       It hasn't warmed since 1998
       SirNubwub... You have to pause a moment and think about it though. What are the chances that we're going to see any kind of cooling trend? The radiative properties of CO2 are very clear. It's basic physics. Increased levels of CO2 are going to warm the planet. If that's somehow not happening, then there's about 150 years of well established science to rework (i.e., that's not a very likely scenario). The chances that "global warming has stopped" is extremely unlikely. Where real science is operating right now is a matter of how much warming we're going to see from the expected increases in atmospheric CO2. Is the IPCC central estimate of 3.0C for 2XCO2 correct? Is it slightly lower? 2.5C? Or is it actually higher? ~4.0C? The difference between climate sensitivity of 2.5C and 4.5C has major implications for what human society needs to do to address the situation.
69281. KR at 05:40 AM on 16 December 2011
       (Fahrenheit) 451 ppm
       John Hartz - Personally, I'm a fan of less moderation, not more. While skept.fr has put quite a lot of volume on this thread (and others), with an unfortunate tendency to use several hundred words where a few would suffice, I still consider this discussion worth having, and quite revealing/educational. * Skept.ft's objections have been shown to be a False Dichotomy between shutting down the world economy - and unchanged business as usual (BAU), claiming that any action leads directly to crushing the developing world. (S)he has simply ignored the middle ground, of replacing current power generation with renewables as quickly as possible. Even a 1 for 1 replacement of aging power plants would lead to a significant (if not, perhaps as speedy as we might hope) cut-back in CO2. But skept.fr appears reluctant to even consider the middle range. * Skept.fr has also neglected the very real costs of continuing climate change, insisting that any limits on power generation are hugely more detrimental than mitigating climate change - again, a false dichotomy, and a strawman argument as well (as every plan I have seen includes ongoing increases in total power generation). This despite multiple studies indicating that mitigation will be far more cost effective than adaptation! * Finally, the ongoing focus on and criticism of any targets appears to be simple avoidance - 'No target is reasonable, so we shouldn't have any targets - take it easy, don't emphasis the risks, or you sound crazy', to paraphrase. This is simply a call for inaction. False dichotomies, strawmen, ignoring information on climate change impacts (It's not bad) - I see these as frequent 'skeptic' approaches that all should be familiar with.
69282. Tristan at 05:15 AM on 16 December 2011
       Climate sensitivity is low
       I love Kathryn Schulz! Her talks aren't as good as her book though.
69283. MarkR at 05:14 AM on 16 December 2011
       Is there a case against human-caused global warming in the peer-reviewed literature? Part 3
       #58 dana: Soden & Held, 2006 found, if I understand it correctly, that the size of the 'hot spot' makes no difference to final warming in models. It can be undetectable, or it can be huge. It doesn't matter. The reason being that the 'hot spot' comes from more water condensing in the upper atmosphere, the latent heat causes the warming. This cools the surface (the latent heat comes from surface evaporation). The bigger the hot spot, the bigger the surface cooling. But the bigger the hot spot, the more water vapour stays in the upper atmosphere too so the more greenhouse effect you have. Iirc, Soden & Held found that models always found that the greenhouse effect of the extra water vapour always outweighed the latent heat cooling (the 'lapse rate feedback' or 'Earth cooling by sweating'), and always by about the same amount. This leaves Douglass' speculation with no evidence that I'm aware of, but I do plan to research this in more detail in the future.
69284. John Hartz at 05:14 AM on 16 December 2011
       (Fahrenheit) 451 ppm
       Why on earth does SkS allow someone like "skept fr" to completely hijack a comment thread like this one and turn it into his/her personal blog site?
69285. Bob Lacatena at 05:12 AM on 16 December 2011
       It hasn't warmed since 1998
       133, SirNubwup, No. To have some confidence (one can never "know") that warming has stopped you would need to see 17 consecutive years in which you see no trend (mind you, that's not 17 years of no warming each year, but instead no trend in that span of 17 years) in both the atmosphere and the oceans. One would hope that in that same period you would also see an halt in the melting of glaciers and arctic ice and other indicators of a warming world.
69286. Bruce at 05:10 AM on 16 December 2011
       Ocean Acidification: Corrosive waters arrive in the Bering Sea
       Rob, I don't think I'd write off the oyster industry. Instumentation has improved to the point where aragonite saturation can be monitored real time at the water intakes for the hatcheries . This allows much improved success in culture of spat because the hatcheries can adapt to pH changes and to some degree modify seawater TA when necessary. Adult oysters are doing fine in current conditions in the Pacific Northwest. I am a commercial fisherman for 40 years and in no way would I dismiss the threat of O/A . I just think we need to acknowledge the successes we have along the way in what is going to be a very long battle. The Oyster industry has really pulled together and made some real progress so rather than writing them off you should go eat some oysters tonite. Thanks for the blog thanks for the hard work and thanks for taking on O/A. Bruce
69287. SirNubwub at 04:50 AM on 16 December 2011
       It hasn't warmed since 1998
       130 Sphaerica So, if I understand correctly, for global warming to be seen to be stopped, we would have to see steady temperatures in both the atmosphere and the oceans. Just one of these is not sufficient. Is this correct?
69288. John Russell at 04:50 AM on 16 December 2011
       Is there a case against human-caused global warming in the peer-reviewed literature? Part 3
       @Richard Arrett If you're trying to suggest that you've in effect been banned, then you're wrong. Make any comment you like (within the rules) on the relevant threads and they will be answered. For instance for questions and comments about CO2 and its relation to current warming, put the relevant words into the search box (top left) and it will show you all the suitable threads. Don't worry, everybody will know you've posted there because the regulars monitor the 'comments' link directly at the top of this column. Happy browsing.
69289. Richard Arrett at 04:27 AM on 16 December 2011
       Is there a case against human-caused global warming in the peer-reviewed literature? Part 3
       Thank you for your patience. I will not respond to the later comments directed to me, as it appears my responses would be considered off topic.
69290. muoncounter at 04:14 AM on 16 December 2011
       The End of the Hothouse
       "The fall in CO2 concentration was from 1000-1200 ppm down to 600-700ppm, at which point it was cool enough to allow glaciers to start to form." If this result holds up to scrutiny, this could easily be a landmark paper, calling for a re-evaluation of the 'CO2 lags temperature' myth. This comment from lead author Pagani is especially relevant: "The onset of Antarctic ice is the mother of all climate 'tipping points,'" he said. "Recognizing the primary role carbon dioxide change played in altering global climate is a fundamentally important observation." An important prior work by the second author is Huber et al 2004: Considering that (1) Antarctica was not kept warm by subtropical currents, (2) evidence of above-freezing Eocene continental interior winter temperatures occurs in high latitudes of both hemispheres, and (3) substantial carbon cycle changes coincide with the Eocene-Oligocene boundary, the most parsimonious explanation of the enigmatic global warmth of Eocene climate was that it was caused by atmospheric mechanisms, such as greenhouse gas radiative forcing ... and potential feedbacks ... . The implication is that changes in greenhouse gas concentrations and subsequent feedbacks were primarily responsible for climatic deterioration into the Oligocene.
69291. dana1981 at 03:38 AM on 16 December 2011
       Is there a case against human-caused global warming in the peer-reviewed literature? Part 3
       ahaynes - this is basically an update to Oreskes' original paper which examined the AGW consensus in the peer-reviewed scientific literature. If a paper puts forth an alternative explanation which might explain a large chunk of the recent warming, I believe it's counted on the 'skeptic' list. However, such papers are rare, as this survey found.
69292. dana1981 at 03:34 AM on 16 December 2011
       Is there a case against human-caused global warming in the peer-reviewed literature? Part 3
       For those arguing that Douglass et al. should be included in the rejecting papers, this is simply not correct. The tropical troposphere 'hot spot' is not an anthropogenic fingerprint, as we have discussed on SkS several times. Thus this paper cannot bring the human-caused global warming theory into question. The authors of the paper suggest that their results might mean less future warming than is currently expected. Whether or not that conclusion is supported by their research (which I think is questionable), again, it does not bring human-caused global warming into question, but rather the magnitude of futhre human-caused warming. Thus it does not belong on the 'reject' list.
69293. muoncounter at 03:19 AM on 16 December 2011
       Galactic cosmic rays: Backing the wrong horse
       Eric, Here's another version of a similar graphic: -- source It's difficult to tell if Be10 is that much lower now then in the past; at these scales, the short-term noise is larger than most of the long term variation. I found this Beer slide presentation; the 14th page after the title has another Be10 graph. The lowest points are roughly 48ka, 30ka, 22ka and 2ka. He cites a paper by Muscheler et al in EPSL 219, which I haven't gone after, as the source of that data. I don't see how this line of inquiry, without a mechanism for a climate connection to cosmogenic radioisotopes, helps one way or the other.
69294. ahaynes at 03:02 AM on 16 December 2011
       Is there a case against human-caused global warming in the peer-reviewed literature? Part 3
       (A lot of comments above, some of which might have addressed my Q) This series examines whether there's "a substantial case against human-caused global warming" but I think that's too broadly worded and doesn't get at the major objection now - some people these days will admit humans make some (unspecified but nonzero) contribution but raise the prospect that natural factors are more or equally important; would this constitute making "a case against human-caused GW"?. Also it's not clear whether "human-caused" would include other human actions whose effects don't include increased GHGs. I'd like to see a clarification of what's being looked at. (perhaps this has been addressed & I've overlooked it.)
69295. Dave123 at 02:37 AM on 16 December 2011
       Is there a case against human-caused global warming in the peer-reviewed literature? Part 3
       Richard Arnett: One can be mild mannered and still be arrogant, condescending and rude. From Mel Brooks "History of the World" As noted you've traipsed merrily into a thread about peer-reviewed literature supporting a "skeptical" take on AGW, and have nothing to cite. I hope you've moved your discussion over to any of the threads about the numerous areas you are misinformed about.
       Moderator Response: Richard Arnett, there is a requirement, not just a suggestion, by this site's Comments Policy, for all comments to be on topic of the particular original post. Your initial comments were allowed to stand, so that you could be gently pointed to the relevant threads. Your comments most certainly are welcome, but only if they are on the relevant threads. If you want to comment on multiple topics, you must split your comments across the relevant threads. Your grace period has passed, so if you post irrelevant comments on threads where you already have been warned not to, your comments will be deleted.
69296. Tom Curtis at 02:22 AM on 16 December 2011
       (Fahrenheit) 451 ppm
       skept.fr @95, I am not interested in re-arguing the whole case with you. My intervention was simply to point out your biases and prejudices behind whose ramparts you where criticizing SkS as being insufficiently skeptical (a refrain you keep on returning to regardless of evidence). One key bastion of your fortress of bias was the claim that the 2 degree C (450 ppmv) guard rail was not based on science but on political discussions and decisions. I have comprehensively demolished that pretense above. You now retreat behind a further bastion, that we can ignore particular scientific discussions of the preferable target because it is not part of an IPCC summary, and hence not part of the consensus of climate science. However even this bastion is shadow rather than rock. If you wish to maintain the IPCC has provided no guidance on this issue, you need to explain the purpose of the updated reasons for concern and the discussion of mitigation strategies in Working Group 2. While doing so you would do well to note their opinion that:

       "...quantifying market-based damages associated with MOC changes is a difficult task, and current analyses should be interpreted as order-of-magnitude estimates, with none carrying high confidence. These preliminary analyses suggest that significant reductions in anthropogenic greenhouse gas emissions are economically efficient even if the damages associated with a MOC slowing or collapse are less than 1% of gross world product. However, model results are very dependent on assumptions about climate sensitivity, the damage functions for smooth and abrupt climate change and time discounting, and are thus designed primarily to demonstrate frameworks for analysis and order-of-magnitude outcomes rather than high-confidence quantitative projections."

       Fairly obviously a cost/benefit analysis that only demonstrates "orders of magnitude outcomes" has no inherent superiority to guard rail analyses, or analyses of stabilization targets. More crucial to this point,however, is the discussion in WG 3, in which they state:

       "[S]ignificant benefits result from constraining temperature change to not more than 1.6°C–2.6°C above pre-industrial levels. These benefits would include lowering (with different levels of confidence) the risk of: widespread deglaciation of the Greenland Ice Sheet; avoiding large-scale transformation of ecosystems and degradation of coral reefs; preventing terrestrial vegetation becoming a carbon source; constraining species extinction to between 10–40%; preserving many unique habitats (see IPCC, 2007b, Chapter 4, Table 4.1 and Figure 4.5) including much of the Arctic; reducing increases in flooding, drought, and fire; reducing water quality declines, and preventing global net declines in food production. Other benefits of this constraint, not shown in the Table 3.11, include reducing the risks of extreme weather events, and of at least partial deglaciation of the West Antarctic Ice Sheet (WAIS), see also IPCC, 2007b, Section 19.3.7. By comparison, for ‘best guess’ climate sensitivity, attaining these benefits becomes unlikely if emission reductions are postponed beyond the next 15 years to a time period between the next 15–55 years. Such postponement also results in increasing risks of a breakdown of the Meridional Overturning Circulation (IPCC, 2007b, Table 19.1)."

       The prospect of 10-40% of all species on Earth going extinct illustrates the severity of the risk imposed by AGW, a risk which increases with increasing temperatures. Of course, what you won't find in the IPCC reports is an explicit statement as to the appropriate temperature for a guard rail. That is because the IPCC reports are advise to policy makers, not policy making themselves. However, the clear advise of AR4 WG3 is that in the range of 1.6 to 2.6 degrees C, impacts are severe but potentially not catastrophic, where as beyond that all bets are of. In other words, the IPCC may indicate that there will be massive ecosystem collapse at temperature increases greater than 4 degrees C, with a minimum species loss of 35% (making global warming potentially the second or third largest ever mass extinction, and significantly worse than the K-T extinction event that destroyed the dinosaurs), but it is still open to policy makers to decide that life in a greater than K-T extinction event is an acceptable option. Of course, as citizens, they have no doubt that anybody who would take that option either is secure in the fact that they will not witness it, or are insane. Returning to the primary, and very simple point. You have indicated very forcibly that the 2 degree guard rail is simply a manufactured number for political convenience. I have demonstrated that, on the contrary it is a figure based on science, and science reported by the IPCC. The final decision was made by policy makers, but it was an informed decision. The question is, then, will you withdraw your objection to the 2 degree C guard rail as a reasonable basis of discussion? Or will you instead show by your intransigence that when the science is against you, you just ignore it?
69297. Bob Lacatena at 02:10 AM on 16 December 2011
       (Fahrenheit) 451 ppm
       skept.fr, You continually present a false dichotomy. You require a choice of either "abandon fossil fuels 100% immediately" or "stay on fossil fuels until the entire world is safe from poverty." This fails because obviously there are solutions in between. The key point, however, is that any transition away from fossil fuels is going to take a lot of time so we have to start now. In Tom's words:

       It takes time to transition from a high carbon to a low or zero carbon economy. With the best will in the world it could not be done in less than twenty years, and ideally it would be phased in over 40 to 50 years (ie, through the natural cycle of replacement of obsolete power plants). Anything faster incurs significant increased costs.

       You are repetitively ignoring this reality by continually falsely representing the problem as an either/or choice between all or nothing. This is not the case.
69298. pbjamm at 02:09 AM on 16 December 2011
       Is there a case against human-caused global warming in the peer-reviewed literature? Part 3
       Richard Arnett@30 "I thought that CO2 followed temperature by around 700 years." & "...the natural warming which may have occurred since 1850 could be the cause of the higher CO2 levels." 1850 was not 700 years ago. So either, no it is not the cause of the current CO2 increase or CO2 response to temperature increase is MUCH larger than we think. 600 more years of this would put as at ~1000ppm Of course all this ignores the known output of CO2 due to human activities.
69299. Bob Lacatena at 02:03 AM on 16 December 2011
       Climate sensitivity is low
       For the record, the 16.6 W/m^2 RW1 keeps throwing around is from his own entirely incorrect logic that there is a direct relationship between the radiation leaving the surface and the radiation emitted at TOA, and that this requires a linear "gain" and therefore the creation of non-existent energy. It basically comes from a completely flawed understanding of the system, I think because he is trying to translate it entirely into his own misapplied EE concepts of "gain," "feedback" and control theory rather than by understanding climate science and the actual system under discussion. The clearest (convoluted) path to understanding his logic is here, but in a nutshell, 16.6 W/m² is a ridiculous constraint of his own devising, and there is no arguing with it, because he can't get past the mumbled incantations and heavy incense needed for his magical spells.
69300. DSL at 01:12 AM on 16 December 2011
       Climate sensitivity is low
       DB, you should probably tack that comment on to every post that RW1 makes, so that no one makes the mistake of engaging him/her in discussion. It will also act as a standing demonstration of exactly what denialism is--a one-way street where the denialist presents the Truth and refuses to admit error. I've asked "wrongologist" Kathryn Schulz to target the global warming issue through interviews with a number of opinion-makers and scientists. I hope she ends up doing so. It's a very rich area for her--not just in the exploration of what happens when people who are committed to alternative theories come up against hard evidence against them, but also in statisticians' and scientists' relationship with modeling, in people who are paid to be publicly wrong, and in how scientists deal with being wrong.

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