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Comments 59301 to 59350:

59301. JoeT at 08:53 AM on 8 May 2012
       Lindzen's Clouded Vision, Part 1: Science
       Thank you all for your very informative responses. This site performs a very valuable service for those of us who just want to get a grasp on the basic science.
59302. Tom Curtis at 08:03 AM on 8 May 2012
       Lindzen's Clouded Vision, Part 1: Science
       Joe T @16, you have already received a number of informative answers, but I'll chip in as well to clarify a particular issue. Climate sensitivity is defined by three terms: a) The Transient Climate Response is the more or less immediate response to a new forcing. It has a technical definition, but can probably be best understood as the response that will be achieved in the minimum time it takes to measure an average climate state (a climatology),ie, within 30 years. It is dependent on a number of fast factors, including (most importantly) the cloud albedo feedback, the water vapour feedback, and the lapse rate feedback, but any factor which influences the Equilibrium Climate Response (or Charney Climate Sensitivity) will influence it. b) The Equilibrium Climate Response (also known as the Charney Climate Sensitivity,or the Fast Feedback Response) is the temperature change required to restore equilibrium assuming fast feedbacks but no slow feedbacks. Fast feedbacks include the cloud albedo effect, water vapour feedback, the lapse rate feedback, but also changes in albedo due to reduced sea ice or snow cover. They are characterized by feedbacks that reach an equilibrium state with temperature within decades. In contrast, slow feedbacks such as changes in albedo due to the loss of permanent ice sheets (Greenland Ice Sheet, West Antarctic Ice Sheet), changes in albedo due to massive changes in ecology (eg, the Amazon Basin becoming Savannah with isolated rainforest); changes in heat distribution due to large scale changes in ocean currents, and equilibriation of the partial pressures of CO2 in atmosphere and deep ocean. Slow feedbacks take centuries to millenia to reach equilibrium. As indicated, the Equilibrium Climate Response only accounts for fast feedbacks, and ignores all slow feedbacks. As a result, the time scale to the Equilibrium Climate Response is dominated by the time taken to establish equilibrium between the deep ocean and the surface in terms of temperature. As indicated above by others, that results in a rapid (less than 100 years) rise to about 66% of the response, followed by a slow movement to the equilibrium state (200 years or so). c) The Earth System Climate Response (or Earth System Sensitivity) is the response after all feedbacks, fast and slow have reached an equilibrium state. This takes centuries to millenia, and in the long term is governed by the glacial rate at which ice sheets melt. (OK, so I like puns. So sue me.) Because of this, we are unlikely to ever reach the Earth System Climate Response for the full measure of human emissions to the atmosphere. That is because while the ESCR takes millenia, over millenia the CO2 concentration will be drawn down. In fact, it will be drawn down to about 25% of the initial peak atmospheric concentration within a century or two, but take tens of millennia to return to pre-industrial levels. Therefore, unless the response to short term factors drives a release of natural CO2/Methane into the atmosphere of the same order of magnitude to total human emissions, our long distant descendants will face the Earth System Response to about 25% of our peak CO2 concentration rather than to the full peak concentration. That response will be about 60% of the peak warming (with large uncertainties). Given that the climate response predicted for about 2100 for BAU is about 60% of the Equilibrium Climate Response for the emissions, that is also the temperature increase we can expect for a period comparable with the entire extent of human civilization since the invention of agriculture, although it will peak at a higher level in the period 2100-2300 (assuming emissions growth is sharply curtailed at 2100 or earlier).
59303. dana1981 at 07:46 AM on 8 May 2012
       Lindzen's Clouded Vision, Part 1: Science
       James Wight also had a very good post on the various measures of climate sensitivity (fast, slow, etc.). Rob Painting is working on a relevant post right now, and I might also do one on issues like 'warming in the pipeline', depending on what Rob covers in his post.
59304. tmac57 at 07:05 AM on 8 May 2012
       Lindzen's Clouded Vision, Part 1: Science
       @Albatross #8- At least Lindzen is moving in the right direction. Maybe he just needs a bit more 'negative feedback' from his peers so that he can finally reach equilibrium ;)
59305. Bob Lacatena at 07:04 AM on 8 May 2012
       Lindzen's Clouded Vision, Part 1: Science
       JoeT, You have to remember that in any case these are only very simple one-dimensional mathematical models of a real world situation. What really determines how large climate sensitivity is and how long it takes to reach a new equilibrium temperature is not determined by some simple physics equation like F=ma or e=mc2. As the Arctic summer ice melts, the open ocean absorbs more radiation rather than reflecting it. This is a positive feedback, but it depends on when the Arctic summer ice melts, and how soon in the year. It can also be a self-reinforcing feedback (sooner melt = warmer planet = sooner melt), as most are, but it is bounded by the limited summer season in the Arctic. Eventually the days get dark. How long will it take (if ever) until the ocean is warm enough to start releasing rather than absorbing CO2? How long will it take (if ever) for deserts to expand or for rain forest to turn into savanna (releasing more CO2 but also increasing the albedo of the land), and how large will the net positive feedback be? How long will it take (if ever) and how much methane will be released from permafrost? The reality of the situation depends on the slow feedbacks, but any one dimensional equation intending to model them is just a very rough approximation.
59306. Kevin C at 06:49 AM on 8 May 2012
       Lindzen's Clouded Vision, Part 1: Science
       JoeT: I think this graph is what you are look for, from Hansen and Sato 2011. An exponential isn't a good model, because there are so many different timescales involved. Given that this curve is from a climate model, I have no real idea what the uncertainties are like. However you can also estimate the shape of the response function from past climate over various timescales. There's a nice paper by Padilla and Vallis (2011) on that.
59307. JoeT at 06:29 AM on 8 May 2012
       Lindzen's Clouded Vision, Part 1: Science
       Dana1981 Great piece, thanks for the response. Sorry to drag on about this, but I think the issue is very important, especially to neophytes like myself. An additional blog post would be great. I'm still trying to reconcile what you wrote with #2 and #11. In your example, if we choose a simple exponential and pick that in 75 years, 0.7 of the warming will occur, that gives us a time of around 60 years. That also means that roughly 99% of the warming will occur in less than 300 years. My question -- is there only 1 time constant as in this example, or is there indeed a fast and slow time constant such that additional warming due to CO2 alone takes place over millenia? Thanks!
59308. Cole at 05:54 AM on 8 May 2012
       ConCERN Trolling on Cosmic Rays, Clouds, and Climate Change
       Muon, The Agee results were Spurious, (not genuine, authentic, or true) as per the inability to properly observe GCC changes, and as a result an inability to show proper correlations in either direction. From the paper: 'Research on the GCR-cloud correlations must continue, particularly in view of the two physical mechanisms mentioned above (as well as the uncertainty in the reliability of the ISCCP lower troposphere cloudiness to show the proposed correlations).' The paper itself isn't useless, but your waving it around as proof is. The rest of your papers are just as innefectual for the same reason. Now, let's get back to examining what fits. Bond et al. (2001), who in studying ice-rafted debris in the North Atlantic Ocean determined, in Svensmark’s words, that “over the past 12,000 years, there were many icy intervals like the Little Ice Age” that “alternated with warm phases, of which the most recent were the Medieval Warm Period (roughly AD 900-1300) and the Modern Warm Period (since 1900).” And as Bond’s 10-member team clearly indicates, “over the last 12,000 years virtually every centennial time-scale increase in drift ice documented in our North Atlantic records was tied to a solar minimum:" http://www.sciencemag.org/content/294/5549/2130.short Parker (1999) noted that the number of sunspots had also doubled over the prior 100 years, and that one consequence of the latter phenomenon would have been “a much more vigorous sun” that was slightly brighter. Parker pointed out that spacecraft measurements suggest that the brightness (B) of the sun varies by an amount ΔB/B = 0.15%, in step with the 11-year magnetic cycle. He then pointed out that during times of much reduced activity of this sort (such as the Maunder Minimum of 1645-1715) and much increased activity (such as the twelfth century Mediaeval Maximum), brightness variations on the order of ΔB/B = 0.5% typically occur, after which he noted the mean temperature (T) of the northern portion of the earth varied by 1 to 2°C in association with these variations in solar activity, stating finally that “we cannot help noting that change in T/T = change in B/B.” http://www.co2science.org/articles/V2/N14/C3.php . Digging deeper into the subject, Feynman and Ruzmaikin (1999) investigated twentieth century changes in the intensity of cosmic rays incident upon the earth’s magnetopause and their transmission through the magnetosphere to the upper troposphere. This work revealed “the intensity of cosmic rays incident on the magnetopause has decreased markedly during this century” and “the pattern of cosmic ray precipitation through the magnetosphere to the upper troposphere has also changed.” With respect to the first and more basic of these changes, they noted that “at 300 MeV the difference between the proton flux incident on the magnetosphere at the beginning of the century and that incident now is estimated to be a factor of 5 decrease between solar minima at the beginning of the century and recent solar minima,” and that “at 1 GeV the change is a factor of 2.5.” With respect to the second phenomenon, they noted that the part of the troposphere open to cosmic rays of all energies increased by a little over 25 percent and shifted equatorward by about 6.5° of latitude. And with the great decrease in the intensity of cosmic rays incident on earth’s magnetosphere over the twentieth century, one would have expected to see a progressive decrease in the presence of low-level clouds and, therefore, an increase in global air temperature, as has indeed been observed: http://trs-new.jpl.nasa.gov/dspace/bitstream/2014/20689/1/98-1743.pdf A number of other pertinent papers also appeared at this time. Black et al. (1999) conducted a high-resolution study of sediments in the southern Caribbean that were deposited over the past 825 years, finding substantial variability of both a decadal and centennial nature, which suggested that such climate regime shifts are a natural aspect of Atlantic variability; and relating these features to other records of climate variability, they concluded that “these shifts may play a role in triggering changes in the frequency and persistence of drought over North America.” Another of their findings was a strong correspondence between the changes in North Atlantic climate and similar changes in 14C production; and they concluded that this finding “suggests that small changes in solar output may influence Atlantic variability on centennial time scales: http://www.sciencemag.org/content/286/5445/1709.short Van Geel et al. (1999) reviewed what was known at the time about the relationship between variations in the abundances of the cosmogenic isotopes 14C and 10Be and millennial-scale climate oscillations during the Holocene and portions of the last great ice age. This exercise indicated “there is mounting evidence suggesting that the variation in solar activity is a cause for millennial scale climate change,” which is known to operate independently of the glacial-interglacial cycles that are forced by variations in the earth’s orbit about the sun. They also reviewed the evidence for various mechanisms by which the postulated solar-climate connection might be implemented, finally concluding that “the climate system is far more sensitive to small variations in solar activity than generally believed” and that “it could mean that the global temperature fluctuations during the last decades are partly, or completely explained by small changes in solar radiation: http://www.gg.rhul.ac.uk/elias/teaching/VanGeel.pdf Noting that recent research findings in both palaeoecology and solar science “indicate a greater role for solar forcing in Holocene climate change than has previously been recognized,” Solanki et al. (2000) developed a model of the long-term evolution of the sun’s large-scale magnetic field and compared its predictions against two proxy measures of this parameter. The model proved successful in reproducing the observed century-long doubling of the strength of the part of the sun’s magnetic field that reaches out from the sun’s surface into interplanetary space. It also indicated there is a direct connection between the length of the 11-year sunspot cycle and secular variations in solar activity that occur on timescales of centuries, such as the Maunder Minimum of the latter part of the seventeenth century, when sunspots were few in number and earth was in the midst of the Little Ice Age. http://www.nature.com/nature/journal/v408/n6811/abs/408445a0.html In discussing their findings, the solar scientists say their modeled reconstruction of the solar magnetic field “provides the major parameter needed to reconstruct the secular variation of the cosmic ray flux impinging on the terrestrial atmosphere,” because, as they continue, a stronger solar magnetic field “more efficiently shields the earth from cosmic rays,” and “cosmic rays affect the total cloud cover of the earth and thus drive the terrestrial climate.” Next, using cosmic ray data recorded by ground-based neutron monitors, global precipitation data from the Climate Predictions Center Merged Analysis of Precipitation project, and estimates of monthly global moisture from the National Centers for Environmental Prediction reanalysis project, Kniveton and Todd (2001) set out to evaluate whether there is empirical evidence to support the hypothesis that solar variability (represented by changes in cosmic ray flux) is linked to climate change (manifested by changes in precipitation and precipitation efficiency) over the period 1979-1999. In doing so, they determined there is “evidence of a statistically strong relationship between cosmic ray flux, precipitation and precipitation efficiency over ocean surfaces at mid to high latitudes,” since variations in both precipitation and precipitation efficiency for mid to high latitudes showed a close relationship in both phase and magnitude with variations in cosmic ray flux, varying 7-9 percent during the solar cycle of the 1980s, while other potential forcing factors were ruled out due to poorer statistical relationships. http://www2.geog.ucl.ac.uk/~mtodd/papers/grl_2001/grl_total.pdf Carslaw et al. point out that cosmic ray intensity declined by about 15 percent during the last century “owing to an increase in the solar open magnetic flux by more than a factor of 2.” They further report that “this 100-year change in intensity is about the same magnitude as the observed change over the last solar cycle.” In addition, we note that the cosmic ray intensity was already much lower at the start of the twentieth century than it was just after the start of the nineteenth century, when the Esper et al. (2002) record indicates the planet began its nearly two-century-long recovery from the chilly depths of the Little Ice Age. http://www.sciencemag.org/content/298/5599/1732 These observations strongly suggest that solar-mediated variations in the intensity of cosmic rays bombarding the earth are indeed responsible for the temperature variations of the past three centuries. They provide a much better fit to the temperature data than do atmospheric CO2 data; and as Carslaw et al. remark, “if the cosmic ray-cloud effect is real, then these long-term changes of cosmic ray intensity could substantially influence climate.” It is this possibility, they say, that makes it “all the more important to understand the cause of the cloudiness variations,” which is basically the message of their essay; i.e., that we must work hard to deepen our understanding of the cosmic ray-cloud connection, as it may well hold the key to resolving what they call this “fiercely debated geophysical phenomenon.” Now I've shown you correlations without having to rely on GCC data (that we can not observe) You guys seem to be grasping at straws trying to dismiss this. Finally to quote the press release from CERN: 'Climate models will need to be substantially revised'
59309. funglestrumpet at 05:19 AM on 8 May 2012
       2012 SkS Weekly Digest #18
       My 'canary' is the lengths to which Monckton has to go in order to keep his audience feeling amused, instead of feeling insulted, which is how they would feel if he gave them time to stop and think.
59310. dana1981 at 05:19 AM on 8 May 2012
       Lindzen's Clouded Vision, Part 1: Science
       shoyemore @12 - aerosols are sort of a "fudge factor" in models by necessity, simply because we don't have good measurements as to the strength of their cooling effect. We do have good measurements of the temperature change, and of most other forcings, so the aerosol focing is allowed to vary within certain constraints in order to best fit the observed temperatures. You can call that a 'fudge factor' if you like. However, as noted in the post above, they do not have zero temperature influence, as Lindzen assumes. Better to treat them as a 'fudge factor' than a neglected factor.
59311. dana1981 at 05:13 AM on 8 May 2012
       Lindzen's Clouded Vision, Part 1: Science
       JoeT @10 - the timescale to equilibrium is something of an unresolved question, which I think we'll be addressing in a future blog post. Off the top of my head, I think that after 50-100 years, somewhere in the ballpark of two-thirds to three-fourths of the equilibrium warming is realized. It mainly depends on how efficiently heat mixing happens in the oceans, which is the somewhat unresolved question. So yes, if we were to suddenly stop emitting CO2, we'd see most of the consequent warming within a century, but not all of it.
59312. JoeT at 04:39 AM on 8 May 2012
       Lindzen's Clouded Vision, Part 1: Science
       CBDunderson: Thanks very much for your post. Actually the hundreds to thousands of years was in post #2 just above, which also says the response time is not decades. What I got from your post is that there is a fast and slow time response. Could you elaborate for me -- or point me in the right direction -- as to what constitutes the physical processes that account for the two time scales. Thanks again. I've learned a great deal in the short time I've been following this site.
59313. shoyemore at 04:29 AM on 8 May 2012
       Lindzen's Clouded Vision, Part 1: Science
       Incidentally, Professors Lindzen and Happer, plus Roger Cohen (formerly of Exxon) have responded in the letters section of the May 9th New York Review of Books to Yale Professor William Nordhaus' critique of the op-ed "No Need to Panic About Global Warming" by the group known as the Wall Street Journal 16 Their response to Nordhaus is basically a scatter gun (or Gish gallop, if you prefer!) with not much science. The most scientific parts are general attacks on climate models for not including all sources of variability, and for including aerosols as a "fudge factor" only. Perhaps a future post could cover this? Professor Nordhaus' reply is shorter, clearer and more effective, IMHO. In the Climate Casino SkS covered Nordhaus' original article here: Nordhaus sets the Record Straight
59314. CBDunkerson at 04:01 AM on 8 May 2012
       Lindzen's Clouded Vision, Part 1: Science
       JoeT, I think the 'hundreds to thousands of years' you are referring to (which doesn't appear to be in the comments to this post) may be the 'long term' sensitivity. Most estimates put the eventual warming for doubled CO2 at around +6 C after all slow feedbacks have played out over hundreds to thousands of years. We're about half way to doubled CO2 forcing now, so ~3 C would be the eventual long term warming expected from current CO2 levels. However, the +3 C figure more frequently cited is the 'fast feedback' value... if we double atmospheric CO2 levels then we expect to see +3 C warming within decades. How many decades depends mostly on how fast we raise the CO2 level, but certainly less than a hundred years. The warming we've been seeing the past few decades has been the result of direct CO2 forcing (which is more or less immediate) and these 'fast feedbacks'. If we could stop CO2 at current levels then within about 50 years the FAST warming would stop at around +1.5 C (we're currently at ~ 0.8 C) and then only slowly go up to +3 C over the course of hundreds of years.
59315. Tom Curtis at 03:10 AM on 8 May 2012
       Ocean Heat Content And The Importance Of The Deep Ocean
       BC @59, as you seem to have realized, 1000 Petagram = 1 trillion tonnes, and yes, to have a better than 50% chance of avoiding rises in Global Mean Surface Temperatures below 2 degrees C, we need to keep total CO2 equivalent emissions below 1 trillion tonnes. It is generally accepted that rises of GMST or more than 2 degrees C will have major, net harmful effects, and a considerable body of opinion thinks the relevant limit is 1.5 degree C, to avoid which we need to keep CO2 levels below 350 ppmv, or as we have already passed that, quickly bring CO2 levels back down. With regard to the ENSO effects, changes in ENSO state have been shown to significantly effect the accumulation of Ocean Heat Content from 0-750 meters, with the "missing" heat turning up in the 750-2000 meter range. That is certainly much deeper than the mixed layer, but whether you would call it the upper levels? I don't know. What is more, I known no more about it than that, so I cannot comment on the specific movements of heat involved.
59316. DSL at 03:09 AM on 8 May 2012
       2012 SkS Weekly Digest #18
       My "canary" is the biosphere's visible response to the warming planet. That is like the squawk of the canary as it struggles to breathe. The thump of the canary on the cage floor will be widespread food riots.
59317. JoeT at 03:00 AM on 8 May 2012
       Lindzen's Clouded Vision, Part 1: Science
       Sorry to even further low-brow the thread, but I'm trying to catch up on the topic. Great article, but when reading it my immediate question was in fact -- what is the time scale for equilibrium? I see in the comments that the answer is hundreds to thousands of years. Is it mistake to infer from this 1- That present warming is a result of emissions from a hundred years and more. 2- That if all CO2 emission were cut-off now, it would take hundreds of years to see the warming stop.
59318. Rob Honeycutt at 03:00 AM on 8 May 2012
       Lindzen's Clouded Vision, Part 1: Science
       What really got me when watching the video where Lindzen states that it "should have" warmed 3C by now was... If you look at any projections by any scientists, or the IPCC, there is no one anywhere who has ever put out a graph showing 3C of warming by now. Zero. None. It's a completely outrageous claim that Lindzen makes. It's the mother of all straw man arguments. I was literally slack-jawed in amazement that he made such a statement.
59319. Albatross at 01:48 AM on 8 May 2012
       Lindzen's Clouded Vision, Part 1: Science
       Dana @4, I agree with you that Alex is missing the point. I would also argue that he is not accurately reflecting the content of Dr. Held's recent blog post, but I won't let us get sidetracked by that red herring. "He's arguing for ~1°C sensitivity, for which there is almost no supporting evidence." It is worse than that Dana. Lindzen has, for a long time, been arguing for a climate sensitivity less than < 1 C for doubling CO2. In 1997 Lindzen published a colloqium paper in PNAS, he stated that: "Indirect estimates, based on response to volcanos, suggest sensitivity may be as small as 0.3–0.5°C for a doubling of CO2, which is well within the range of natural variability." In the much refuted Lindzen and Choi (2009) paper, Lindzen and his coauthor claim that: "...and ERBE data appear to demonstrate a climate sensitivity of about 0.5 C which is easily distinguished from sensitivities given by models." There is that 0.5 C again... In Lindzen and Choi (2011), they revised their estimate upwards slightly to 0.7 C for doubling of CO2: "As a result, the climate sensitivity for a doubling of CO2 is estimated to be 0.7K (with the confidence interval 0.5K - 1.3K at 99% levels)".
59320. Michael Whittemore at 01:31 AM on 8 May 2012
       2012 SkS Weekly Digest #18
       My "canary in the coal mine" is increased infrared radiation from CO2 hitting the Earths surface. It seemed so obvious to me when I found that out. It also seems very cunning how the "Words of the Week" explain this process so well just as the "canary" question is asked. But this increased radiation seems impossible to ignore. Even if there was a cloud feedback due to cosmic rays, there would really only be a cooling and warming from their fluctuations. The average global temperature would still increase with added CO2.
59321. Kevin C at 01:07 AM on 8 May 2012
       Lindzen's Clouded Vision, Part 1: Science
       DC: Good question. The relationship is indeed non-linear - logarithmic in fact. Since we are now at 1.41 x preindustrial, and 1.41=√2, the forcing is almost exactly half way to that of a doubling of CO2. The 76% figure comes from adding the CO2-equivalent of all the other greenhouse gasses we've put into the atmosphere.
59322. DC at 00:59 AM on 8 May 2012
       Lindzen's Clouded Vision, Part 1: Science
       Sorry to low brow the thread but I was wondering how the figure of 76% (additional) of pre-industrial CO2 forcing is arrived at? my current thinking is along the lines of: CO2 in 1750 ~= 280 ppm CO2 in 2012 ~= 393 ppm So CO2 increase is about 114 ppm which is an increase of (114/280) 41% Where am I going wrong? Is this related to the non-linear relationship between forcing and increased CO2?
59323. Michael Whittemore at 00:59 AM on 8 May 2012
       Lindzen's Clouded Vision, Part 1: Science
       Great post, and good commenting, people are so quick to twist the truth. Even if this truth twisting is done advertently or inadvertently, climate science needs people to make sure the topic is on the right track. Keep up the good work.
59324. Alexandre at 00:58 AM on 8 May 2012
       2012 SkS Weekly Digest #18
       Issue of the week: for me, it's the obvious and known Arctic sea ice.
59325. dana1981 at 00:51 AM on 8 May 2012
       Lindzen's Clouded Vision, Part 1: Science
       alexharv074 @1 - first of all, we at SkS always keep our posts free of ad hominem attacks, so there is nothing unusual about this. Second, you're not addressing the point of the post. The point of the post is not that no evidence exists for relatively low sensitivity. The point is that Lindzen's argument - that the fact that the planet hasn't warmed 3°C means climate sensitivity is low - is wrong. Third, Schmittner's best estimate equilibrium sensitivity was 2.3°C, and there are good reasons to believe the estimate is too low, as we discussed in our post on the paper (mainly their estimate of the interglacial temperature change is much lower than any previous estimate). Fourth, Lindzen isn't arguing for ~2°C sensitivity, which would be within the IPCC range. He's arguing for ~1°C sensitivity, for which there is almost no supporting evidence. I'm glad we do at least agree that Lindzen's claim is ludicrous.
59326. BC at 23:32 PM on 7 May 2012
       Ocean Heat Content And The Importance Of The Deep Ocean
       I've just looked it up. The limit was that emissions must be less than 1 trillion tonnes = 10**18. Sorry about the confusion.
59327. BC at 23:29 PM on 7 May 2012
       Ocean Heat Content And The Importance Of The Deep Ocean
       Actually maybe it was a trillion Kg = 10**15?
59328. BC at 23:23 PM on 7 May 2012
       Ocean Heat Content And The Importance Of The Deep Ocean
       Tom @58, thanks. That explains the CO2 side quite well. Is a 1000Pg pulse = a trillion gigatonnes (=10**(12+9+6)=10**27g)? I'm pretty sure that this was a target mentioned by Julia Guillard (Australian Prime Minister) last year that the world needs to stay below. The La Nina occurs when there is a flow across the Pacific from east to west with the ocean up-welling colder water near Peru (this is my understanding anyhow). So I'm guessing from your not mentioning it that this doesn't involve the deep ocean, just the upper levels?
59329. Bob Lacatena at 23:14 PM on 7 May 2012
       Lindzen's Clouded Vision, Part 1: Science
       Alex, I see no reference whatsoever to a sensitivity of 1.9˚C in the Schwartz paper. Are you sure that you are reading it properly? It's a very interesting exercise in estimating climate sensitivity, and yet it is constrained (as the paper itself points out) by the inherent errors of the observations used as inputs into the model as well as the method used. In particular, multiple sources of inputs are used, yielding a range of sensitivities that roughly cover the span presented by the IPCC AR4. And as always the issue is muddled by the difficulty in estimating the negative aerosol forcing over the past 100 years. You also seem to fail to distinguish between transient and equilibrium climate sensitivities, and the distinction is important. I suggest you read up on that. Lastly, I myself have to question any method that attempts to infer equilibrium climate sensitivity from short term observation. The reality is that I think one needs at least 100 years of clean data, maybe more, with a constant, measured forcing, in order to do so. Trying to estimate equilibrium climate sensitivity from 20th century observations is a little like trying to guess the top speed of a race car on a track by observing one minute of acceleration and braking in deep mud on a hazy day from a distance of 5 miles with an hour glass for a timer. The bottom line here is that (1) the discussion of climate sensitivity is complex and (2) Lindzen's claim is ludicrous.
59330. Kevin C at 22:05 PM on 7 May 2012
       Lindzen's Clouded Vision, Part 1: Science
       Alex: I'm puzzled by your response. There is certainly a real discussion on the actual values of both the TCR and the EQS. You highlighted some low estimates, we could also find some high ones. But the IPCC itself suggests estimates in the range 2-4.5C for EQS, and 1.9C certainly isn't out of the question. However, Lindzen's claim is that according to the consensus position we should have seen 3C temperature rise by now, rather than 0.75C we have seen. But that's not what the consensus scientific position says. The 3C figure he quotes is a response to total change in forcing from pre-industrial, not GHG forcing alone. And the time required for that response to be reached is measured in centuries to millenia, not decades (e.g. Hansen and Sato 2011 Fig 7, or similar figures from Held, Padilla and Vallis 2011, or Rypdal 2012). So I don't understand how Lindzen's claim can be seen as anything other than a complete misrepresentation of the consensus position.
59331. adelady at 21:42 PM on 7 May 2012
       2012 SkS Weekly Digest #18
       Yes, I noticed that. Very gratifying. A nice recognition that the approach here is useful for others aiming to educate.
59332. bill4344 at 21:13 PM on 7 May 2012
       2012 SkS Weekly Digest #18
       I was pleased to see the number of SkS graphics appearing in the DCCEE's patient debunking of Plimer's book targetting schoolkids.
59333. DouglasM at 19:34 PM on 7 May 2012
       Why Are We Sure We're Right? #2
       (-Snip-)
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59334. Riccardo at 17:59 PM on 7 May 2012
       Greenhouse Effect Basics: Warm Earth, Cold Atmosphere
       I think it's worth adding to this discussion that the rectifying properties of a diode are due to a voltage barrier or gradient inside the material. Following this analogy (not a good one I think), it's the temperature gradient in the atmosphere that causes the its "rectifying" properties. Indeed, the greenhouse effect depends on the lapse rate (temperature gradient) and there would be none if the atmosphere was isothermal. The OLR would be the leakage current of the "atmospheric diode", luckly not a good one :)
59335. alexharv074 at 17:45 PM on 7 May 2012
       Lindzen's Clouded Vision, Part 1: Science
       Hi Dana, Thanks for the interesting post and for keeping it unusually free of ad hominem attacks. I would like to question your claim that,

       There simply is no question - Lindzen's claim that the Earth hasn't warmed as much as expected, which is the basis of his low climate sensitivity argument, which is the basis of all remaining relatively credible climate contrarianism, is entirely false based on three fundamental physical flaws in his argument, as demonstrated by simply comparing the models and observations.

       This is a very bold statement, and I think an exaggerated and false statement. I think you would be more skeptical if you were less selective in your appeals to the literature. We have seen Gillett et al. (2012), even discussed here, that suggests the transient climate response (TCR) is in fact less than expected, based on observations. And just the other day Isaac Held published a very interesting article here arguing that Gillett et al. are probably about right. Prof. Held also argues that the observations of TCR are consistent with fixed relative humidity models with no cloud feedback. Recently, Schwartz (2012) has also argued from observations of the 20th century that equilibrium climate sensitivity is about 1.9 K per doubling of CO2. Although Held apparently has reservations about extrapolating from TCR to ECS, I do note that the IPCC AR4 states that climate models, without the cloud feedback, predict a climate sensitivity of about 1.9 K, the same as what Schwartz has found. We have seen other arguments from paleodata - e.g. Kohler et al. (2010); Schmittner et al. (2011) showing, for completely different reasons, that ECS is likely to be about 2.3 K per doubling CO2. Finally, Prof. Lindzen has referred to a number of other papers in literature that support lower sensitivity and you appear to have ignored all of them.
59336. muoncounter at 13:03 PM on 7 May 2012
       ConCERN Trolling on Cosmic Rays, Clouds, and Climate Change
       Cole#40: "I'm not simply declaring Agees results as 'meaningless'." Sorry, what I must have misunderstood is your #30: "So the results of said paper are spurious at best." If you've read anything beyond the abstract of Agee's quite comprehensive review of the current literature, you wouldn't be throwing 'spurious' around: It is clearly evident that the positive trend in previous solar cycles and lower troposphere cloudiness has not continued for the cycle 23-24 QP, which adds to the controversy of the GCR-CCN hypothesis. Not only has the GCR count received a record high level during the cycle 23-24 QP, but the lower troposphere global cloudiness has dropped to a record low level, further challenging the validity of the hypothesis. I suggest you study the remaining references in this post that question the cosmic ray-climate connection. Then there's Love 2011, as noted here and Laken 2011: We find no evidence that widespread variations in cloud cover at any tropospheric level are significantly associated with changes in the TSI, GCR or UV flux, and further conclude that TSI or UV changes occurring during reductions in the GCR flux are not masking a solar-cloud response. "As for your Realclimate post, how would you like it if I started relying on blog-science?" That 'blog-science' was written by Dr. Jeff Pierce, who has published on cloud nucleation mechanisms. Refer also to Pierce and Adams 2009: In our simulations, changes in CCN from changes in cosmic rays during a solar cycle are two orders of magnitude too small to account for the observed changes in cloud properties; consequently, we conclude that the hypothesized effect is too small to play a significant role in current climate change. "the direct correlation between CRF and T over the Holocene that clearly doesn't exist with CO2" Talk about an 'own goal.' Please show us the cosmic ray flux data - not any of those suspicious 'proxies' - for the Holocene. Then refer to numerous articles here showing the excellent correlations between CO2 and temperature.
59337. Bob Loblaw at 12:48 PM on 7 May 2012
       Lessons from Past Predictions: Hansen 1981
       pauls: I've actually had a chance for a quick look at the IPCC section you linked to. Please refer to the section of text in Section 8.6.2, and note the part where is says:

       and is often simply termed the ‘climate sensitivity’. It has long been estimated from numerical experiments in which an AGCM is coupled to a simple non-dynamic model of the upper ocean with prescribed ocean heat transports (usually referred to as ‘mixed-layer’ or ‘slab’ ocean models) and the atmospheric CO2 concentration is doubled.

       You referred in your comment to the "slab ocean", and called it "little more than a surface with a low heat capacity". In contrast, the IPCC report talks about the mixed layer (roughly 60-100m thick) of the ocean, and specifically says that it has "prescribed ocean heat transports". That doesn't sound like "a surface with a low heat capacity" to me. It sounds like they are leaving out the deep ocean, not calculating ocean movements, but just specifying the heat storage and transfer within the mixed layer. Can you explain why you think this is "just a surface with a low heat capacity"? I will continue to look through the IPCC report, to see if there are more details. It may be necessary to look at some of the papers in its references, however. I'd like to know more about just what "ocean heat transports" are prescribed.
59338. chuckbot at 12:17 PM on 7 May 2012
       Report Warns of Rapid Decline in U.S. Earth Observation Capabilities
       cutting off funding from the only people who are minding the storm. Talk about shooting yourself in the foot. Off topic, but... what are the longitudinal bands in the image above? Dust? Artifacts?
59339. Cole at 11:25 AM on 7 May 2012
       ConCERN Trolling on Cosmic Rays, Clouds, and Climate Change
       I'm not simply declaring Agees results as 'meaningless' I'm saying you are misunderstanding them. Agee reported on a 'possible' disconect and even mentioned large uncertainty in the data they used to come to the conclusion. As I've stated many times now, we don't have the technology to detect a 2% change in GCC so your whole answer up untill the microphysics comment is ineffectual. Furthemore, just because we can not detect a two percent change does not mean it isn't happening. As for your Realclimate post, how would you like it if I started relying on blog-science? Maybe I should look up some denier sites and use their arguments? If you want to refute, please use a solid peer-reviewed science. "Your jump from Kirkby's " Kirkby is just a small example on this subject, I was only trying to show you the direct correlation between CRF and T over the Holocene that clearly doesn't exist with CO2. I was simply making a statement in the context of the Holocene, that is very much supported by the data.. If you would really like I could show you a plethera of papers, on this subject spanning the entirety of the geologic eras and show you exactly the same thing. Your statement of the Agee paper being a "swing and a miss" for Svensmark ended up being an own goal for yourself, given what the paper actually said. (-snip-).
       Moderator Response: [DB] Off-topic snipped. Again, please review the Comments Policy linked earlier before commenting further.
59340. KR at 10:21 AM on 7 May 2012
       ConCERN Trolling on Cosmic Rays, Clouds, and Climate Change
       skywatcher, Cole - And don't forget: (d) A bad paper is published, recognized as such by the majority in the field, and essentially ignored (not cited) by anyone who isn't following the same bad logic. For example: the Gerlich and Tscheuschner paper claiming the 2nd law of thermodynamics (truly silly, now disavowed even by folks such as Fred Singer) was well on its way to that fate when repeated trumpeting by 'skeptics' led to published rebuttals.
59341. skywatcher at 09:54 AM on 7 May 2012
       ConCERN Trolling on Cosmic Rays, Clouds, and Climate Change
       You've got to love how arguments from authority operate in one direction in the skeptic universe. Suddely because a skeptic's paper is successfully published by the RAS, it is deemed to be flawless, having clearly undergone thorough and utterly rigorous peer-review by experts in the relevant field(s). Yet nearly every relevant climate expert on the planet, and certainly every relevant scientific organisation, agrees that anthropogenic CO2 is causing most of the current rapid warming. Many thousands of papers have been published with this view, all peer-reviewed. Why the disconnect for the 'skeptics'? Bad papers get published. Lets ignore for a moment that the RAS are probably not the greatest repository of scientific expertise on climate, and mention a few other papers. One (McLean et al 2009) was published in GRL even though the authors removed the long-term trend then argued that the short-term variation was causing the long-term trend. Another paper confused degrees with radians at a crucial point. Yet another paper (Spencer and Braswell IIRC) managed to examine a bunch of models and leave out the model runs that demonstrated their hypothesis was critically flawed. So Cole, quite apart from muoncounter's excellent points, which of the following statements do you agree with: (a) There is no such thing as a 'bad' paper and everything that is peer-reviewed is clearly good science. Peer-reviewers are always flawless in their work. (b) Some bad papers get published. These bad papers are either ignored, or subseqiuent responses are published that demonstrate the critical flaws in the reasoning of the author(s). Peer reviewers are human, and despite doing an excellent task in filtering out the very worst papers, occasionally give a pass to a poor paper. This most often happens when the journal's expertise is not ideally matched to the subject matter. [An example of a response is Foster et al 2010, the response to McLean et al 2009] (c) The RAS has never, ever, published a paper subsequently discovered to have been flawed in some way.
59342. Bob Loblaw at 09:45 AM on 7 May 2012
       Lessons from Past Predictions: Hansen 1981
       pauls: Thanks. I'll try to read through it. I'll also be off the net for the next week or so, so I won't be able to reply soon.
59343. muoncounter at 09:26 AM on 7 May 2012
       ConCERN Trolling on Cosmic Rays, Clouds, and Climate Change
       Cole#35: You can summarily declare Agee's results 'meaningless' if you like, despite publication in the Journal of the AMetSoc. Perhaps not as prestigious as the Monthly Notices of the RAS, but that really proves nothing. But look at the references in the post: Calgovic, Erlykin x3, Lockwood x2, Pierce... all with negative re-evaluations of the so-called 'looks pretty good' correlation between CR flux and temperatures. Lakin (more than paper) had similar results. Your objection to Agee ("we can't really detect changes in GCC") makes it clear how weak the whole GCR->cloud story really is. We just came through a 50 year high in GCR flux (2009): Where are the clouds? As for the supposedly 'glove-fitting microphysics,' Pierce took that apart at RealClimate. Perhaps you'd be better off with the 'does not fit' defense. Your jump from Kirkby's "... question of whether, and to what extent," to "Clearly, carbon dioxide is not the all-important dominating factor... " in one sentence is stunning. Kirkby's language is the same style as the 'possible disconnect' you found objectionable in Agee. We've gone from GCR->clouds to supernovae->GCR->cooling->mass extinctions. Of course, you've missed the fact that the peak SN frequency on Svensmark's graph is some 50 Myrs before the PTr extinction. You've also ignored what should be the primary objection to the supernova idea: they're not necessarily the source of GCRs. And then there's Montenegro et al 2011, showing that the PTr extinction coincided with increased ocean anoxia and that decreased ccean pH "brought about by the increase in atmospheric CO2 is biologically significant.". Supernovae doing that, too? "you guys deliberately misrepresent papers... " That kind of language usually gets your comments deleted. Please try to come up with more than 'that statement is ludicrous' -- and have a look at the Comments Policy.
59344. pauls at 09:17 AM on 7 May 2012
       Lessons from Past Predictions: Hansen 1981
       Bob Loblaw, IPCC chapter 8. Check the caption for table 8.2.
59345. Tom Curtis at 09:15 AM on 7 May 2012
       Why Are We Sure We're Right? #2
       Tarcisio José D @37, I have responded in detail on another, more appropriate thread, and suggest that you do likewise. I understand that you are using "Google translate" in order to overcome a language barrier. You are to be commended for your efforts to do so, but "Google translate" is not up to the task, and I recommend that you enlist the aid of a technically proficient, and bilingually fluent friend to aid you. In essence, my response points out that the atmosphere does in fact have the diode like property of emitting more radiation downward to the surface than it does upward to space (which my not be quite what Tarcisio meant by his use of the phrase), and that it has this property despite the fact that no individual component of the atmosphere has the property. I go on to point out that detailed modelling shows the property to exist, and that those models have been shown to be remarkably accurate by empirical observation, and that indeed that diode like quality of a higher downward IR radiation from the atmosphere than the upward IR radiation at the Top of the Atmosphere has been observed empirically.
59346. Tom Curtis at 09:05 AM on 7 May 2012
       Greenhouse Effect Basics: Warm Earth, Cold Atmosphere
       This is a response to Tarcisio José D from another thread. In response to my explanation, he asks:

       "My question is, which quality of your atmosphere makes it only absorbs IR radiation that rises in the atmosphere and free passes IR radiation that the atmosphere emits more toward the ground."

       In fact nothing I wrote suggests the gases within the atmosphere act as a diode. Each IR active gas will absorb IR radiation with equal facility from all directions, and emit it with equal probability in all directions. However, the atmosphere as a whole acts as a diode. That is, it emits more IR radiation upwards to space than it does towards the ground. It does this because the emission to space comes from higher, and cooler layers within the troposphere as explained in the article above, and also in my posts 36, 51, and 58 above. Importantly, Line By Line (LBL) models, which calculate the IR emission and absorption in the atmosphere at each wave number, and which require each layer of the atmosphere absorbs IR radiation with equal facility whether the radiation comes from below or above, or from the atmosphere or the surface, and which requires that each layer radiates equal amounts of IR radiation upwards and downwards, produce this diode like effect, provided that the atmosphere is cooler at higher altitudes. You can see this for yourself with Modtran. If you run the model on default settings, the outgoing IR radiation equals (Iout) 287.844 W/m^2. Altering the settings to sensor altitude = 0 km, and "looking up" shows the downward long wave radiation from the atmosphere (Iout) is 348.226 W/m^2. The accuracy of these LBL models is shown in the section "Settled science" in the main article, and in my post number 43. It should be noted that the observed upward IR radiation from the top of the atmosphere is 239 W/m^2, while the observed downward IR radiation at the bottom of the atmosphere is 333 W/m^2, amply illustrating this diode like quality of the atmosphere as a whole, even though no individual component (gas molecule) of the atmosphere acts like a diode. I understand that Tarcisio José D is facing a considerable language barrier in communicating in English, and is to be commended for his efforts to overcome that barrier. I recommend that he read carefully this post, the main article above, and the posts linked to in my response. If he is having difficulty in understanding the issue, I also recommend he enlist the aid of a technically proficient friend who is fluent in both English and his native language (which I assume is Spanish or Portuguese). Google translate is not up to translating technical discussions accurately, and will only lead to ongoing confusion. Finally, the issue he needs to address is, why should we prefer his hand waving explanation to the detailed results of LBL models which have proven remarkably accurate in predicting the observed radiation in the atmosphere, whether sampled from satellites, the ground, or aircraft at intermediate levels of the atmosphere?
59347. adelady at 09:03 AM on 7 May 2012
       2012 SkS Weekly Digest #18
       "canary in the coalmine"? I take that as something we'll look back on in 30-50 years time and say - someone should have put it all together right then and there. For me, that's the reduction in inflows to Perth's water storages in the 70s. Few cities are better placed to show the effects of expansion of Hadley cells ..... and that it's a bad thing.
59348. dana1981 at 09:01 AM on 7 May 2012
       Why Are We Sure We're Right? #2
       victull @28 - you're comparing different energy imbalance estimates. As I said, take a look at the Levitus post. Model-based estimates of a 0.9 W/m2 imbalance were probably over-estimates. We'll have more on this in the future.
59349. Cole at 07:18 AM on 7 May 2012
       ConCERN Trolling on Cosmic Rays, Clouds, and Climate Change
       Tom, "A higher sea level will result in flooding of low inland ar-eas, and increase the total length of coastline and the area of the continental shelves. This results in more heterogeneous habitats in which species can evolve, leading to an increase in diversity, and Miller et al. (2005) offer this as the reason for the development of the three eukaryotic phytoplankton clades (lineages) that dominate the modern ocean. >But the rough correspondence between marine invertebrate diversity and sea level seen in Fig. 19 is plainly not the whole story
       Moderator Response:

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59350. scaddenp at 07:00 AM on 7 May 2012
       Why Are We Sure We're Right? #2
       Tarcisio Jose D. What I find so interesting is the statement: "I am very sure that I am right in saying that all who believe in the warming of our planet is caused by CO2 are totally wrong," which then implies that you have chosen to believe a couple of video from dubious sources with laughable science over the bulk of known heavyweight physics. Now why would do such a strange thing? As you are finding out, things are more complicated than thought and the science is better, but why did you choose to trust such strange sources over known science. You claimed to be "very sure" which is also extraordinary. It would be really interesting if you could explain why you trust one source over another. As the "rectifier". DK, Bob, I dont think Jose is claiming the atmosphere works like a rectifer. He is trying to understand Tom and thinks that climate theory requires the atmosphere to behave like a rectifier because he hasnt understood the theory. This isnt that straightforward to follow. Eli Rabett did a good explanation I think but I cant find it. Any got a pointer? Jose, people are trying to make the greenhouse model explicable but ultimately the test is in doing the calculation. The real model with the equations can be found in Ramanathan and Coakley 1978. You need a computer to calculate the equations, but how do we know that is it right? Well because it predicts what we can observe of spectrum etc, with a very high degree of precision.

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