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Comments 59951 to 60000:

59951. Tom Curtis at 00:04 AM on 22 April 2012
       Roy Spencer finds negative feedback
       Uncle Ben @8, when somebody says "You can't argue with mathematical facts", they are setting up to deceive you. Maths is a formal language. Like all formal languages, it has no innate interpretation. In order to say something - anything - about the world with maths, you need to set up an interpretation, and that interpretation can be false, contradictory or deceptive just as much as any statement in English. When somebody tells you that maths can't lie, their sole purpose (if they are not simply foolish) is to draw your attention away from the potential fallibility of interpretation. There is a reason why lies, damned lies and statistics represents a progression.
59952. Realist at 23:48 PM on 21 April 2012
       Renewables can't provide baseload power
       Michael Sweet @29. I read the article you linked, but you really shouldnt blame the nuclear power company, you should blame the legislators you voted for that signed the contract you consider bad. Having said that, it is not uncommon for governments to make contributions to all sorts of large projects, because without a contribution the project may not be viable without charging more for their product, and most governments try to keep utility prices down.
59953. barry1487 at 23:40 PM on 21 April 2012
       Global Surface Warming Since 1995
       I'm a little unclear on the problem with transferring Santer's 17-year recommendation from the satellite to the surface records of global temperature. To my mind, they are quite similar, even though measuring dfferent properties, and the surface records are less variable (respond less to ENSO) than satellite, thus more likely to be statistically signficant. Eg, the 17-year trends (1994 - 2010 inclusive) for GISS, NOAA, HadCRUt3v and HadCRUt4 are all statistically significant. Not the case for either of the satellite records. Makes me think applying the 17-year 'rule' is even stronger for surface temps. ?
59954. MA Rodger at 23:22 PM on 21 April 2012
       Why Are We Sure We're Right? #1
       In the post Ari Jokimäki: begins his contribution "My first thought on Rob's question is: right about what?" It's a question that hasn't been answered here & in places this comment thread does stretch the argument beyond solely the science. In my view, being "Right about AGW" begins with the no-brainers which the likes of Lindzen agrees is settled. I then go beyond to dismiss what I see as the falacious assertions of Lindzen on climate sensitivity & the role of natural causes in the temperature record of recent decades. The final step within the science is to link emissions for likely 'sensitivities' with actual physical impacts (sea level rise, regional/seasonal temperature/rainfall), thus to show at what point Bangladesh drowns or Java melts under the business-as-usual futures. My view on this is far less well founded. I 'believe' that even a sensitivity of 1.5 would lead to unacceptable consiquences, but such a 'belief' does depend on the next step which extends beyond science. Beyond the science there is the question "So what do we do about it?" and that has attracted just as many crazy & not-so-crazy denialist arguments for doing little or nothing, almost as many as the science has. One big difficulty is that the scientific agruments are now replaced by economic, technological and political arguments which provide a far less disciplined environment for a debate that involves so much uncertainty. And in explaining 'why I'm sure I'm right' beyond the science is something I'm a lot less practised in.
59955. muoncounter at 23:13 PM on 21 April 2012
       Roy Spencer finds negative feedback
       Uncle Ben: Interesting paradox. You represent that 'a little model' should be taken seriously, as it and it alone somehow correctly captures 'mathematical facts'. Yet when questioned as to how the little model reproduces some of the largest variations in the record, your reply is 'climate is complicated.' Nicely contradictory. Which position do you actually hold? Because you cannot simultaneously hold both. Perhaps instead of dismissing more complete models so casually and accepting Spencer's reductionism, you should take the time to actually learn what the more realistic models entail. You might then retract your 'need to brush up on statistics' allegation, which is utterly unfounded and without merit.
59956. Uncle Ben at 22:39 PM on 21 April 2012
       Roy Spencer finds negative feedback
       @skywatcher " With low climate sensitivity, how do you get glacial-interglacial cycles, ..." I have no idea, but climate is complicated. If what is offered here is mere handwaving, why was Mt. Pinatubo's contribution to temperature variability so laboriously removed from the data when trying to measure sensitivity? Is it not demonstrated in that exercise that removing a competing source of variability is important and reduces the calculated sensitivity? And when Spencer removed the forcing effect of cloud variation from sources other than dH/dt, he reduced the apparent sensitivity result and permitted a PRECISE measurement of the sensitivity. That has never been done before. The idea of extracting more information from satellite data by noting the time sequence of the data points is a novel and valuable contribution that eventually will get the appraisal it deserves. (If you quip "none," history will judge you.) @Bailey "Without evidenciary links to supportive works in the literature, ..." Isn't the correction for recent volcanic forcing in the literature? The removal of extraneous variation from the ancient data is not in the literature because it is impossible. It is too late. The impact on sensitivity measurement has not been adequately realized. Maybe climate scientists need to brush up on statistics. You can't argue with mathematical facts.
       Moderator Response:

       [DB] The volcanic damping effects on temperature due to aerosol release quickly fade out, even on the non-geologic timescale (with notable exceptions, such as the Siberian Traps).

       In the paleo record, volcanic effects quickly fall into the obscurity of noise in the data at the resolutions available. Thus their effects are already compensated for by the climate system. Perhaps more study of the paleo record for edification purposes is in order.

59957. bill4344 at 21:51 PM on 21 April 2012
       Why Are We Sure We're Right? #1
       jzk @ 46- Not many environmental concerns impinge upon something as central to the capitalist economy as it's fossil-fuel-based energy heart; this isn't, say conservation of some high-biodiversity area (I've been directly involved in campaigns that have secured such protections - specifically removing the mining industry - from more than 700 000 Ha of high-quality wilderness), or restricting the production of CFCs. These things hurt, and you get lots of resistance, but they don't threaten the core of the beast.

       Thus, protection of the environment by regulation is essential in a free market system.

       For a start, the Republican Party in the US seems to increasingly believe that regulations, and particularly environmental regulations, have no place in a Free Market economy. And where they go, the rest of the corporate Right (aka 'conservatives', ironically enough) will almost certainly follow; in the Anglo world, anyway. In fact, this process is already becoming evident here in Australia as the mining industry, and specifically its most reactionary sectors, is beginning to very publicly throw its weight around, with denying AGW as a key focus, and with all the attendant anti-Greenie baggage rolling along behind.

       I don't think you are going to get many that would argue "Yes, emitting CO2 is very harmful to the planet, but nevertheless, I have the freedom to emit as much as I please."

       I do think you get many who will say "As long as it is an inherent externality stemming directly from my own affluence I demand the freedom to emit as much CO2 as I please; therefore emitting CO2 is not harmful to the planet. You only want to take my right away because you hate my freedom and envy my affluence." This is, in my experience, the single most common Denier argument one will encounter on the internet, but cognitive dissonance of course means that they will never state it quite so bluntly. But they do come amazingly close... PS: You haven't seen all the 'This blog belches carbon' icons? What sort of sociopathy are we talking there? May I also suggest you read David Michaels' Doubt is Their Product? You may simply have no idea just how many of even the most reasonable - nay, essential - regulationist arguments we have already lost, with virtually no public fanfare...
       Moderator Response: [DB] Politics are Off-Topic on this thread. Other threads exist that cover the focus you discuss (such as this one).
59958. jzk at 21:18 PM on 21 April 2012
       Why Are We Sure We're Right? #1
       bill @ 45, "AGW implies the Free Market, and all the goodies it showers me with, must be constrained; the Free Market must never be constrained: therefore there can be no AGW. Anyone who says there is is clearly an enemy of the Free Market. And of Freedom.™." The problem with that statement is that all environmental concerns would fall into that category. In a free market society, there is no other way to protect the environment other than regulation. The reason is that the environment can't be "owned" but rather it is "shared." Typically, when something is shared by a great number of people, care for that thing ends up lacking. Look at public restrooms for example. People leave their mess there thinking someone else will take care of it, or even just have no concern about it in the first place. Thus, protection of the environment by regulation is essential in a free market system. But we must get it right. I don't think you are going to get many that would argue "Yes, emitting CO2 is very harmful to the planet, but nevertheless, I have the freedom to emit as much as I please."
       Moderator Response: [DB] Politics are Off-Topic on this thread.
59959. Michael Whittemore at 20:27 PM on 21 April 2012
       Shakun et al. Clarify the CO2-Temperature Lag
       I see William has replied to a "comment" of mine, the first "one" I sent him. This is because he cant seem to be able to read all the comments put to him and formulate a response. I for one am not prepared to deal with someone with that kind of intellect. But just so we can all see how he has twisted his stance, his first comment on this thread stated "To enhance or continue global warming is atmospheric CO2 really necessary to explain it?" Link to comment. Williams mentions nothing about LGM, he is simply stating that CO2 should not be needed to explain the global warming which is seen during the end of the last glaciation. This is the bases of the study by Shakun, that it was not a temperature rise that caused a global forcing, but increased concentrations of CO2 that did it. Williams second comment in this thread clearly states that CO2 is not needed to explain any of the warming by saying "It is really the increase in sun light that triggered the whole thing. As more water vapor enters the atmosphere the warming continues [...] I do not understand how CO2 is needed to explain what happened Link to comment. Even when Tom Curtis showed the science and pointed out that " [H2O] was even less able to trigger a self fueled runaway effect as [William was] suggesting" Link to comment. William just twisted his stance by saying "It seems to me that H2O levels alone are enough to explain the GHE effect part of the triggering the end of the ice age." Link to comment. This is the point when William changed his stance from CO2 had nothing to do with warming during the last glaciation, to CO2 had nothing to do with warming during the LGM. Every comment after this time is William trying to explain that CO2 did not cause the warming during the LGM period, which we all know is true. Even in his fourth comment after the one stated above, you can see how he has twisted his stance but continues to make it sound like he has not, "CO2 may have played an important part but I do not see any evidence that it had to be CO2 that caused the ice age to end." Link to comment Of cause by this time he has seen where he was wrong and understands that his stance has changed, so he states "Where am I going with all of this? No, nothing sinister. So far we are talking about just the first 2,500 years" Link to comment My first comment to William I tried to explain that the warming seen in the north after the CO2 rise could not have been caused by H20 by saying "Due to the north's temperature increase lagging CO2 and the fact that the (AMOC) was not causing any warming up there, H2O can only really be seen as a regional short term positive feedback that could not have caused a global warming as is seen." Link to comment. Williams replay to this, "Right now I am talking only the 2,500 year period after the LGM [...] You made a comment about CO2. Considerations of its effects are a primary topic here but a full disscussion is I think beyond the scope of this thread." Link to comment. Personally I think this is the most ridicules comment so far from Williams, this thread is completely about CO2, it has absolutely nothing to do with H2O I can ensure that much.
59960. skywatcher at 19:53 PM on 21 April 2012
       First Look at HadCRUT4
       barry - indeed, I was responding to fydijkstra's claim in #8 that the trend was "zero". That claim was made in direct reference to three single years - 1998, 2005 and 2010, and claimed for a specific 15 year period. It's a strong claim, which is contradicted by the best evidence in the data itself, and I thought a plot for the specific time period in question would straightforwardly show that. It showed that the trend was greater than zero for these 15 years, irrespective of significance. Actually, to paraphrase the great Phil Jones, it's very nearly significant, and adding just a single year makes it significant at the 2-sigma level! The 15 year trend is significant at >= ~90%, but then you're into questions of what level you should apply significance and what the significance actually means, much more nuanced questions. I could, however, argue that the 15-year trend I plotted is statistically significant, but only if I choose a 90% level of significance or lower. 90% is still quite high, and I didn't want to over-complicate the argument! I hope that clears up my position. More importantly, we also have an understanding of the nature and magnitude of the noise inherent in the system (F&R 2011, Santer et al 2011), mostly due to ENSO, and so we do not expect significant warming trends due to AGW for periods less than about 15 years - Santer et al went for 17 years on that one IIRC. So indeed the recent 15-year trend, whether significant or not, does not invalidate anything, as short trends are often measuring the noise rather than the underlying signal. That point shows just how specious the 'global warming has stopped' arguments are, when they look at short segments of data. Pielke Sr came a cropper on this very point here at SkS, when he tried to claim that the trend had changed, based on short recent segments of temperature data ... segments of data which were decidedly noise rather than signal!
59961. michael sweet at 19:30 PM on 21 April 2012
       Newcomers, Start Here
       Brandoneus, At RealClimate they have links to all the data you could ever want. Asking this question indicates that you are not serious in your search, since you would have found the data with a simple GOOGLE search. Do you have the ability to analyze mountains of data? Can you point to an analysis you have done? It was once a common denier meme to claim they want to see the data. Once it was posted to the net they have not looked at it. Most deniers have moved past this stage, since all the data is available.
59962. bill4344 at 17:57 PM on 21 April 2012
       Why Are We Sure We're Right? #1
       I don't know I'm right. I do not have the science background to confidently assert that I understand the maths and physics sufficiently to be able to know with certainty on which side the evidence lies. What I do know is that I can spot where the balance of evidence must lie if one impartially observes the behaviour of the qualified protagonists. One side has a case that is coherent, consistent, and while it contains gaps, those gaps are acknowledged and are not sufficiently large to justify inaction in such a crucial matter. (Particularly as we must establish a 'post-fossil' economy at some stage, anyway!) On the other we have quibbling, and a myopic and frequently-selective obsession with uncertainty that, as Fran Barlow points out above, borders on outright nihilism, and is never consistently applied to the remainder of human knowledge in any case. And that's the strong, merely contrarian, part of the counter-argument. The bulk of what really is a Denier argument is based, it appears to me, on a single logical fallacy - argument from the undesirable consequences of an idea. AGW implies the Free Market, and all the goodies it showers me with, must be constrained; the Free Market must never be constrained: therefore there can be no AGW. Anyone who says there is is clearly an enemy of the Free Market. And of Freedom.™. (Frankly, I'm with Žižek - it's easier to imagine the End of the World than the End of Capitalism! In fact, we may yet find out which is more likely! That's why I sincerely hope there are indeed workable market-based solutions to this problem, and why I also cannot understand the marketeers hysterical opposition to implementing them. How heavy-handed are actions deferred until 2030 going to have to be, do you think?) This results in the egregious conspiratorial nonsense promulgated by the likes of Monckton and Delingpole, which is as risible as anything dished up by the 911 Truthers. And yet these are shining lights in the so called 'skeptic' movement! The 'skeptic' movement tolerates the most alarming tosh without ever seriously cleaning house of the complete nutters, reverts to the beginning of the argument without warning (e.g. Humans not causing the CO2 increase!), and provides absolutely no coherent counter-narrative. It's hardly likely to, in the circumstances. In short, it acts, even at its best, like a law firm hired to defend a rich and well-connected white guy called CO2, and then there's the vast and noisy fools' gallery on Fox and the blogs cheering for 'their guy' to get off! Here are some other truths: If the AGW theory is wrong, we will find out. If the AGW theory is wrong, we'll feel like crap, but we'll accept it, some more quickly than others, but most of us will, eventually. And the evidence that convinces us of this won't come from flaky blog-posts, pal-review, or the 'tear-up Physics' brigade; it will come from proper, stringent, peer-reviewed, hard-scrabble science. Because that's the best evidence of anything we'll ever have. But if you're waiting for 100% certainty before you act, and act decisively, in this matter you really are a fool to yourself and a burden to others. Including - in fact, especially - your own grandchildren...
59963. Tom Curtis at 17:54 PM on 21 April 2012
       Newcomers, Start Here
       brandoneus @205, if you are indeed an old fashioned scientist, you will remember when replication meant repeating the observations yourself, complete with your own collectors notes, rather than getting the results of some body else's hard labour free of charge and responsibility.
59964. Doug Hutcheson at 17:24 PM on 21 April 2012
       Newcomers, Start Here
       brandoneus @ 204, who are you asking and what, exactly, are you asking for? The internet is full of data, on countless millions of topics, having varying degrees of reliability. Google is your friend. If you still can't track down what you are looking for, perhaps you could be a tad more specific. Let us assume you are focussed on a particular aspect of the theory of global warming due to so-called 'greenhouse gasses': What data are you seeking? Do you want original, handwritten documents and recording equipment traces going back 150 years, or would some form of electronic conversion and delivery (which then requires you to trust the source) be acceptable? Are you in a position to recreate all the experiments which produce the data you are looking for, in order to confirm their results, or will you trust that the experiments were performed correctly and observed accurately? At what point in the chain of evidence do you say "I will believe the evidence supplied this far, but no further"? To be sceptical is desirable; to attempt to retrace the steps of every worker in the field since the year dot would be perverse.
59965. brandoneus at 16:40 PM on 21 April 2012
       Newcomers, Start Here
       What I would like is access to all the raw data. I'm one of those "old fashioned" scientists that has to have the original data in the original form it was collected, and the collector's casual/informal notes as well. Can you at least provide us access to the raw data you examined yourself?
       Moderator Response:

       [DB] Curious, that an "old fashioned" scientist up-to-speed enough on technology to be able to post on this forum was not then able to take the next step and search via Google for the requested data?

       Conveniently, links to all said "raw data" are available (as others have noted) here:

       A Post-Easter Basket of Raw Data, Openly Available to All

       The collector's casual/informal notes are an unnecessary complicating factor (adding bias/noise) for old-fashioned scientists seeking to replicate the work of others. Unless your intent was merely to "audit" the work already done...?

59966. Fran Barlow at 16:15 PM on 21 April 2012
       Why Are We Sure We're Right? #1
       One more thing -- data and schedule feasibility. In the real world, data must not only be accurate and salient. To be useful, it must be timely. By timely, we mean that it is available and can be processed in time to inform action. Sometimes, when I'm on hold on the phone, I play a game called "Quadropops". It's a spawning game in which one tries to keep the spawn at bay by continually manipulating the spawn into patterns in which four of the same colour are all in contact. When that occurs, they disappear and any resting on them fall to the next point and if another group of four arises they also vanish. As one accumulates more points, you level up and the spawn comes faster and includes blockers that can only be destroyed by putting one of the four beside them. These two constrain your choice raising the degree of difficulty. By the time you get to level 10 if the spawn have built up much beyond half way, you have no time for careful modelling or the available data. You might have just enough time to work out where things should go but if you take it, they will spawn too early for you to direct them efficiently and you lose control of the game. The basic point is the value of even salient and accurate data is substantially a function of your ability to deploy it to serve an end. The less time you have to process it and develop responses based on it, the less valuable it is. It would have been better to have had less accurate and less salient data a lot earlier providing the extra time you had allowed you to make better use of it. In the case of climate change, while there is continuing marginal value in seeking to narrow error bars in areas where uncertainty remains, the reality is that the marginal value in trying to refine the theory before taking action, in areas where uncertainty is for all practical purposes, frivolous, is negative -- and if the current projections are on the optimistic side, perhaps catastrophically so. How much better off would we be going from 95% certainty to 99% certainty, if, while we waited to act, we also became more certain that the previous modelling was excessively optimistic and that we had a chance of foreclosing some of the harm if we'd simply acted earlier? We'd have to conclude with hindisght that our search for ever more impressive certainty had been very costly indeed, even though we now had it.
59967. Fran Barlow at 15:33 PM on 21 April 2012
       Why Are We Sure We're Right? #1
       It's quite simple really. The phenomenon -- in this case climate change -- can only at this stage be explained if we accept greenhouse gas theory. No other explanation can hindcast the data. If someone can offer a credible and testable alternative explanation for the data that has been measured (including the energy balance data, then I would have some doubt. They'd probably also have to show that both GHGs and this other hitherto undiscovered phenomenon exactly affected the radiation in the same bandwidths as GHGs so that both could co-exist without being additive. It's also clear that if there were some other way of explaining the data that, given the enormous interest in maintaining business-as-usal that pretty much every first world government (and quite a few non-first world governments) has -- that someone would have found it by now. Nothing would help them so much as a plausible alternative theory. Yet to dat, they have nothing. Nada. Given that we have a theory that explains the phenomenon of climate change very well, and no alternative with any credibility, the conclusion is forced. If there were no implications at all for public policy, we might well say "isn't that interesting?" and move on. Of course in that case, the denier movement would be about as active as people who argue that Shakespeare wasn't really the author of Shakespeare's plays. The problem here is one of equivocation. It is so that one cannot prove causality. There is an inevitable bootstrapping problem. The close association with science of maths inclines people to think that scientific proof must be the same as proof in maths. Of course, it isn't because maths is a closed system with deductive reasoning, whereas science is inductive -- we gather more data and rule out explanations that are not plausible leaving behind what may well be truth. Science however is mainly focused on utility -- knowledge about the world that is useful to humans. We would like truth, but we accept that even if we get it, we won't be absolutely certain we have it. What we do want from science are useful insights that can steer us away from doing things that are harmful or sub-optimal. Science doesn't need to give us truth in an absolute sense to meet that standard. It only has to give us the best guidance that rigorous observation and inference-making can achieve. For us, that will count as proof because any human response that is based on that will either be optimal, or sub-optimal in ways that reflect the incompleteness of our work or the limits of our technology. We are doing the best we can with what we have. That is why the objectors to mainstream science are wrong. Of course we can't say with the certainty that attends religious faith that the science as it stands can never be refuted. What we can say is that to reject using what we are very confident is the best explanation for climate change to guide public policy would be a reckless course, on par with ignoring traffic signals on the basis of doubts one had about the consequences of such a course. No court would acquit someone behaving like that on the basis of doubts about the physics and localised impacts of potential collisions. Stripped of the sophistry, the denier claim is incipiently epistemically nihilistic. If the mere partiality of insight makes insight worthless, then all insight is worthless at least until one can show that it is whole and complete. Of course, by definition, one can't have complete insight save by the route of partial insight first. Nobody could know anything and the "skeptic" case would by their own standards implode into nothingness. If they were consistent, they would joing trappist monasteries and take a vow of silence. Of course they aren't consistent. Nobody outside of a mental institution behaves as if the world isn't knowable -- at least in part. Every bit of human progress has been built on partial insight, and it will continue to be so. Intrepid humans have tried things out, sometimes to their personal cost but almost always to the beneift of those who could learn both from their triumphs and their failures. We, more than any other species have learned that learning is a good and worthy thing, to stand on the shoulders of those who have shed light where there is darkness and to spurn those who prattle from the margins that we humans are the playthings of fate. The IPCC-consensus is for mine amply proved to scientific standards. Future science may refine it and make it even more useful as a guide to policy and in the very unlikely event that it is overturned, it will be because someone using the very tools that got us to this point, wielded them even more impressively, not because some self-serving loudmouth did an impression of Mr Horse.
59968. barry1487 at 15:19 PM on 21 April 2012
       First Look at HadCRUT4
       Heh - skywatcher, apologies.
59969. barry1487 at 15:18 PM on 21 April 2012
       Weird Winter - March Madness
       Yeah, those are great vids, and very informative on the jet stream, which has hitherto been a bit of a mystery to me. Well done, greenman.
59970. barry1487 at 14:50 PM on 21 April 2012
       First Look at HadCRUT4
       DB F & R 2011 methodology gives statistically significant trends for shorter periods, yes, but that was not what skywalker was refering to. "1. skywatcher was responding to the claim by fydijkstra that "the warming trend in the last 15 years is zero"; skywatcher ably showed the trend to not only be non-zero, but positive." Just off the first graph that skywatcher diaplyed, one can see that the uncertainty is greater than the trend. Therefore one cannot ably demonstrate a warming trend 'for the last 15 years' from that. So I guess you are saying that the addition of the second observation, warming over the past 30 years, makes skywatcher's conclusions solid. Is this because we take the 30-warming trend to be the null hypothesis, and that the recent 15 year trend does not invalidate it? I ask because I have been among the many (inlcuding commenters and contributors here and Tamino etc) who rebut 'skeptics' who use non-statistically significant trend estimates to make strong claims. Here's another way of doing it, but I don't think it's quite right either: Trend 1967 to 1996 inclusive (30 years, to overcome noise) Now extend to the most up-to-date data point (1967 - Dec 2010?). Not only has the trend continued, it has increased. But, the trend difference is not statistically significant. I am leery - perhaps overly leery considering very low skill in stats - of using non-statistically significant trends to say very much at all.
59971. victull at 14:09 PM on 21 April 2012
       Global Surface Warming Since 1995
       dana1981 Given that global warming is about whether or not the Earth 'system' is warming over time or not, it should be clear to all what is defined as the 'system' and what is a significant time. I think of the 'system' as a spherical shell of air, water and land, bounded by the bottom of the ocean and land surface and the top of the atmosphere. This shell is about 100km thick and has energy entering and leaving at the top and entering from geothermal at the bottom. To stay at equilibrium, the top balance has to be slightly cooling in order to offset the slight warming from the bottom of the oceans. A separate issue is what portion of the warming is caused by human releases of CO2. That portion could be thought of as more than 100%, for if the Earth system would have been naturally cooling and it is now warming, the CO2 effect is offsetting the cooling and then adding some extra warming. Figure 2 suggests that CO2 GHG warming portion is about 100% because the lack of surface temperature increase over 17 years is all due to the cooling effects of Solar, ENSO and Volcanoes. Solar and Volcanoes are accepted as external to the Earth 'system' - ENSO is not - at least over a significant time. Which brings us to what is a significant time. The figure of 15 years has been quoted - 17 years in the above article. My question is whether ENSO should properly be treated as an external forcing over this time period. If not its effects should be excluded from Fig 2.
59972. Daniel Bailey at 14:06 PM on 21 April 2012
       Roy Spencer finds negative feedback
       Agreed. Without evidenciary links to supportive works in the literature, it's an exercise in climastrological mathturbation.
59973. skywatcher at 13:59 PM on 21 April 2012
       Roy Spencer finds negative feedback
       #3 - a handwaving attempt to dismiss the evidence of a whole range of branches of science, doesn't cut it for me I'm afraid. Re-read Knutti and Hegerl. Just one example: With low climate sensitivity, how do you get glacial-interglacial cycles, which are clearly (from timing and frequency) forced by the small Milankovitch orbital variations?
59974. barry1487 at 12:49 PM on 21 April 2012
       Why Are We Sure We're Right? #1
       JimF@30, An acquaintance who is a scientist that studied under John Houghton allowed me to question him about the greenhouse effect and AGW. I mentioned skeptics, and looked for his opinion. I had a couple of long chats, and came away with the realization that he had not given me any kind of position at all on the matter, only what he thought were relevant scientific points (Ari's reply in the OP smacks of). I didn't know what he thought about the 'issue'. "Here," I thought at the time, "is a scientist." (Not long after, one of my (arts) students after 6 months of informal chats in the classroom and pub on climate change, complained I'd said much but given no opinion. I was surprised and pleased as punch - but didn't mistake myself for a scientist :-) I think skepticalscience treads a line between science and activism. Dikran's response was the one I related to most. His clear concession to uncertainty inspires the most trust in what he might say. Whereas the bald certainty of much 'skeptic' commentary inspires no confidence from me. I sometimes make the argument that greater uncertainty is actually a greater impetus to do something. If the hazard is potentially lower because we don't know the bounds as well as we thought, that also means (naively) that the hazards are also potentially greater. But this is not a good 'sell' for an activist, because action is encouraged by bold statements, not deference to uncertainty. The irrational 'skeptics' equate uncertainty with lowering the bottom AND top end of the risk scale instead of widening it.
59975. Brendon at 12:22 PM on 21 April 2012
       Why Are We Sure We're Right? #1
       I believe in AGW and I think I am correct. However this is not my opinion, I just go with what the science is telling us. If new research were presented that showed us why AGW is not a concern, that some strong negative feedback will prevent higher temps, then so long as it were scientifically sound and withstood the test of proper peer-review, then my "belief" would also change. At the moment that seems unlikely for both warming and acidification. Uncertainty however, is not reason for inaction or complacency.
59976. barry1487 at 12:07 PM on 21 April 2012
       GISTEMP: Cool or Uncool?
       UAH satellite data: trends for the poles. North Pole 0.47C/decade South Pole -0.05C/decade http://vortex.nsstc.uah.edu/public/msu/t2lt/uahncdc.lt (see comments above for caveats)
59977. barry1487 at 11:54 AM on 21 April 2012
       First Look at HadCRUT4
       Robert Murphy @ 11 "Hadcrut4 and GISS both show a warming over .11C since the beginning of 1998" Using the skepticalscience trend calculator, I get ~0.083 for both data sets, and the trends are not statistically significant. Did you run trends including more recent data? If so, what was the stat sig for those? skywatcher @ 13 The trend since 1996 is not statistically significant. Caution.
       Moderator Response:

       [DB] "The trend since 1996 is not statistically significant."

       Actually, 2 main points:

       1. skywatcher was responding to the claim by fydijkstra that "the warming trend in the last 15 years is zero"; skywatcher ably showed the trend to not only be non-zero, but positive.

       2. Tamino, in his The Real Global Warming Signal thread, showed that (once controlling for exogenous factors) not only is the warming trend since 1996 statistically significant, but that the trend in all 5 datasets examined showed statistically significant warming since 2000.

       

       QED

59978. LazyTeenager at 11:30 AM on 21 April 2012
       Why Are We Sure We're Right? #1
       The thing which seals it for me is climate skeptic tactics. 1. Relentless attempts to discredit climate scientists or in fact any one who nay says their debating points. 2. Reliance on debating points which are wrong and which they show no inclination to verify for truth. 3. Persistent use of logical fallacies. 4. Cheating and manipulation by a significant number of climate skeptics, particularly the politicals. 5. Consistent promotion of crank science. 6. Lots of arm chair philosophy, but very little science even if you could do the experiments in your kitchen or basement. If they had a strong position they would not need to do any of that.
59979. muoncounter at 10:58 AM on 21 April 2012
       Why Are We Sure We're Right? #1
       In case you missed it, we're well past the point of 'very low sensitivity.'
59980. dr2chase at 10:25 AM on 21 April 2012
       Why Are We Sure We're Right? #1
       It may not be a sensitivity thread, but sensitivity modifies our alarm, and the degree to which it matters whether we are right. Very low sensitivity means it doesn't really matter.
59981. muoncounter at 09:38 AM on 21 April 2012
       Why Are We Sure We're Right? #1
       This is not a sensitivity thread; that's a fine point of the type Scott Denning cautions against. Whether or not we have established the exact sensitivity does not alter the basic facts. Physics doesn't care.
59982. Rob Honeycutt at 09:07 AM on 21 April 2012
       Why Are We Sure We're Right? #1
       When the IPCC states that climate sensitivity below 1.5C is unlikely, they are basing it on a lot of data from a lot of sources. The more interesting recent research on this topic has been essentially clipping the long tail of the distribution. In AR4 they stated that sensitivity above 4.5C could not be ruled out, but newer research is starting to rule it out. Which is a very good thing. 4.5C is ominous enough for me. Hell, 3C is pretty darned ominous as well.
59983. Rob Honeycutt at 09:00 AM on 21 April 2012
       Why Are We Sure We're Right? #1
       Steve Case @ 33.... There are several dozen studies that show this to be the case. See IPCC AR4 WG1 chapter 8.6. In general, you'd have a really hard time explaining glacial-interglacials without feedbacks, along with a host of other things, through which climate sensitivity is measured.
59984. danielc at 08:40 AM on 21 April 2012
       Why Are We Sure We're Right? #1
       @ Noel #32: The consequences of inaction = not having a fridge. Result, spoiled food. The consequences of ordering a fridge that is too large = dealing with the problem while eating fresh and properly cooled food. One consequence is annoying, but tenable... the other is potentially deadly. On climate: the consequences of mitigating emissions and the atmosphere may be expensive, however the side benefits: cleaner power sources, alternative energy technologies, innovation and the creation and burgeoning of potentially huge markets may well offset any short term annoyances. The consequences of doing nothing are by most measures serious, by many measures dangerous, and by some measures, potentially catastrophic.
59985. Steve Case at 08:26 AM on 21 April 2012
       Why Are We Sure We're Right? #1
       Glenn's list is a good one for the basics of the greenhouse effect, but I should like to know if he's sure he's right about the positive feed backs that elevate CO2 Climate Sensitivity from the basic 1.2°C to 3°C or more.
59986. William Haas at 08:25 AM on 21 April 2012
       Shakun et al. Clarify the CO2-Temperature Lag
       I again appoligize for my late responses. I will try to answer the posts that involve my comments but I will do that in numerical order. 88 Michael Whitmore Relatively long term average amounts of H2O in the atmosphere scales with increases in temperature. According to green house gas theory, the increase in water vapor traps more heat which also adds to warming. I am sure that the effect has a stable step response or the earth would have burned up ages ago since we are a water planet. H2O levels react to local temperatures in the short term while natural CO2 levels do not. Natural CO2 levels appear to scale primarily with the heating of large volumes of sea water. During the time period that I have been talking about, acording to the article, global temperatures increased but CO2 did not and according to the article, the situation was triggered by Milankovitch cycles. Levels of H2O always vary in the atmosphere but it is the average values that we are talking about that effect climate. Over most of the earth H2O that leaves the atmosphere is quickly replaced except for water starved locations to include deserts and very cold areas of which there were probably more water starved areas of the earth at the time I am refering to than there are now. Prevailing winds also effect the situation. I do not know what actually caused the warming in the far north. Right now I am talking only the 2,500 year period after the LGM. I was initially wrong about Milankovitch forcing during this period. I apparently had the wrong data and I apologize for that. Looking at the data, it may be that this whole period was really part of the normal ice age varation in climate and that the triggering did not occour until the end of this period. Milankovitch forcing was at a low value and not a high value just before this period. Of course if the northern summers were cooler than usual than southern winters were warmer than ususl and vis versa if we consider Milankovitch forcing to be significant. I think that the seesaw effects are primarily caused by ocean currents. The ocean is a domanant player in all of this. The oceans hold a lot more heat than the atmosphere and they hols it a lot longer. The Oceans work as a giant, nonlinear capacitors. By means of convection ceans can be soaking up heat and or be adding it to the atmosphere and it may not be obvious which is occouring where and at what time. I think that the earth in contact to the ocean's bottom may also add to the oceans's heat capacity. That is why I think that some transfer function analysis may help to increase our understanding of what is really going on. You made a comment about CO2. Considerations of its effects are a primary topic here but a full disscussion is I think beyond the scope of this thread.
59987. noelfuller at 08:11 AM on 21 April 2012
       Why Are We Sure We're Right? #1
       On uncertainty Dikran Marsupial said "In my opinion, a rational cost-benefit analysis, when all relevant uncertainties are properly taken into account, strongly advocates action to mitigate the effects of AGW, rather than adaption when it is already too late." I would ask a person who raises this matter to use a wooden rule, or a dressmakers tape, to measure a distance, supposed to be a gap in a bench say in which a fridge is to go. I would then ask the subject as to certainty in the measurement. Was it read to the nearest millimeter? Could it be read more precisely? How accurate is the instrument of measurement compared to the internationally agreed standard measure? Has the coefficient of thermal expansion been considered in the result? Would it be wise to order a fridge to exactly fit the measurement? What uncertainty should be allowed for in ordering the fridge? Would you decide not to order a fridge given these uncertainties, or is your measurement good enough to act on? Noel
59988. noelfuller at 08:05 AM on 21 April 2012
       Why Are We Sure We're Right? #1
       Sphaerica "He either truly doesn't get that simple, irrefutable fact ... or else he does know it, and is posting an argument like that any way ..." You might value this quote from Plato: "... there is simple ignorance, which is the source of lighter offences, and double ignorance, which is accompanied by a conceit of wisdom; and he who is under the influence of the latter fancies that he knows all about matters of which he knows nothing. This second kind of ignorance, when possessed of power and strength, will be held by the legislator to be the source of great and monstrous [crimes], but when attended with weakness, will only result in the errors of children and old men; ..." Athenian stranger - Plato, Book of Laws, Book IX Translated by Benjamin Jowett Noel
59989. JimF at 08:03 AM on 21 April 2012
       Why Are We Sure We're Right? #1
       Well, this whole article depresses me. I'm not a scientist, but I have been active trying to get local pols to finally react to the danger we are facing. But on this post, this is kind of what we get: "I don't think we are sure that we are right..." "Right about what?" "Let people decide if they want to do anything..." "I haven't made up my mind (we have to do anything about it.." That's it? The skeptic side through the Limbaugh's and climatedepot's of the world say definitively that AGW is a HOAX, that scientists who believe it are lying, and that climatology is bought off. Not a lot of equivocation there! And we are expected to go to battle with "I haven't made up my mind yet...?" Yikes. No wonder more and more people in this country don't accept the reality of AGW.
59990. noelfuller at 07:53 AM on 21 April 2012
       Why Are We Sure We're Right? #1
       from Ari Jokimäki: "I'm on the side that doesn't want to believe anything and thinks that research results should tell us what's happening and possibly what to do about it, if there is such a need." I compare the above with the following: "I taught you not to believe merely because you have heard, but when you believed of your consciousness, to act accordingly and abundantly." - the buddha Gautama The big problem with understanding climate beyond awareness of seasons, and differences while travelling, distinguishing it from weather, is that we are not personally conscious of climate at any large scale. Yet science extends our senses. Science, as in climate science cultivates a form of group consciousness. By it we may "believe of our consciousness" and hopefully "act accordingly and abundantly" Noel
59991. scaddenp at 07:32 AM on 21 April 2012
       Why Are We Sure We're Right? #1
       "The point of view that John took in the book was that one party was absolutely right and trying to convince the unconvinced to the truth of what that right notion was" TOP, I think is more the point that most of what "skeptics" produce is absolutely wrong. If this was a real scientific debate (with peer-reviewed paper supporting multiple viewpoints), then you would have a valid point. The real science is hardly ever debated.
59992. climatehawk1 at 07:10 AM on 21 April 2012
       Why Are We Sure We're Right? #1
       Quark Soup has an interesting thread on this topic today. It's about conversations with Dyson and Happer on the basis for their dissent.
59993. Rob Honeycutt at 07:04 AM on 21 April 2012
       Why Are We Sure We're Right? #1
       William @ 22... Greenhouse theory happens to date back 100 years earlier than does plate tectonics. Greenhouse theory explains a whole lot of things we see including glacial-interglacial cycles and snowball Earth events. AGW is merely an extension of that saying that if WE add the CO2 into the atmosphere (instead of it happening naturally) then we should see similar and proportionate responses in our climate. If you take away greenhouse theory you're left with a whole lot that just can't be explained any other way.
59994. mattho at 07:04 AM on 21 April 2012
       Why Are We Sure We're Right? #1
       A very relevant debate! There is however one fault on both sides: We often confuse denial with skepticism thinking they mean the same. Most people mean by: I am a Climate Change skeptic that they don't think it's happening, or not human made and/or not bad in any way. However skeptic really means to be seeking truth, and not - as most fake experts do - assume they already found it. This is well presented in the recent book: CLIMATE CHANGE DENIAL by H. Washington & J. Cook (2011)
59995. danielc at 07:02 AM on 21 April 2012
       Why Are We Sure We're Right? #1
       Repeatable observations. Period. Full stop. I've never met any of you, but I have access to a mass spectrometer, I know how to use it, and I know the implications of measured values and changes and trends in 18O and 16O, 13C and 14C, Hydrogen and Deuterium...and so on... I can measure them myself. I can do the physics myself. I can repeat the experiments and observations in the classic papers from 150 years ago on forward, and as if by magic, I get the same results they do!! WOW!! "Consensus" is different from "Scientific Consensus" - "consensus" means we all agree that the Red Sox are the best baseball team and the color green is far superior... Scientific consensus means that we all can measure similar things, get similar data, show similar trends and that 2+2 = 4. I know that humans are contributing to atmospheric carbon because I can measure the relative proportions of isotopes of carbon through recent and geologic time... I can measure the change in 13Carbon, and the drop in 14Carbon as older light carbon is added via fossil fuel burning. I know that 18O is heavier and is preferentially left behind on evaporation and preferentially deposited during the initial rain-outs. That the ice in glaciers is enriched in 16O... that the Oxygen that critters make their shells from reflects the isotopic composition of the extant water they live (and die) in. That their shells therefore reflect changes in 18O/16O ratio, which is a function of the ratio between evaporation, rain-out and glacier melt over space and time. I can state those as observations, and whether you know me or not, like me or not, think me a complete wanker who stupidly likes the red sox and the color green... you can measure the same thing... and if we're both competent and honest, we will come up with remarkably, magically similar curves through time.
59996. KR at 06:20 AM on 21 April 2012
       Why Are We Sure We're Right? #1
       william - "Let's say, for the sake of the argument, that all the scientists are wrong. It has happened before." And every time that has happened, it is because a different theory explained the data better than the previous one. When plate tectonics was proposed based on continental edge matching, the theory lacked a mechanism. Only when a mechanism (movement of magma, continents floating on that substrate) was proposed did plate tectonics become a viable theory, one that explained those edge matches without arm-waving. The 'skeptics' appear to be sadly lacking in any such theory. There are lots of half-backed hypotheses through around, most of which are mutually contradictory, and none of which explain the data better than our current physical understanding. In fact, most require ignoring the majority of the evidence - because these hypotheses are incompatible with observations. Glenn Tamblyns list is an excellent start on the range of observations and theoretic domains that new hypotheses must be compatible with. In the meantime, given the quality of the hypotheses thrown around by the 'skeptics', I am reminded of a particular quote: "At times one remains faithful to a cause only because its opponents do not cease to be insipid." - F. Nietzsche
59997. william5331 at 05:52 AM on 21 April 2012
       Why Are We Sure We're Right? #1
       Let's say, for the sake of the argument, that all the scientists are wrong. It has happened before. As recently as when I took Geology 101 in the 1959, my Geology professor, the head of the department, said that plate tectonics was nonsense. So what other reasons are there for slashing our use of fossil fuel. http://mtkass.blogspot.co.nz/2010/10/forget-climate-change.html
59998. Bob Lacatena at 04:31 AM on 21 April 2012
       Murry Salby finds CO2 rise is natural
       11, Dikran, Exactly. But what's even better in this case is that you've got simple, raw physics to fall back on (expected solubility change of CO₂ by measured temperature). You can compute the variation you would expect in the atmosphere based purely on the ocean temperature and partial pressure of CO₂. If you can find an adequate data source and guestimation, you can also adjust that changes in foliage/plant growth. Do that and you'd be left with this clear, unwavering linear trend. And absolutely no further information on where it came from. That is I guess my big problem with Salby... when he identifies the trend he assumes that it must be natural because *insert mumbled, incoherent reasoning here*. And yet what he says clearly says absolutely nothing about the cause of the increase, only the cause of the irregular variation.
59999. Dikran Marsupial at 03:34 AM on 21 April 2012
       Why Are We Sure We're Right? #1
       David Hume established that causal relationships cannot be proven by empirical means. That is as true today as when he said it, and his aphorism about the treatment of evidence is equally correct today a it was then. So Hume wrote things that appear naive from today's perspective? Lets not throw the baby out with the bath water! ;o)
60000. TonyLo at 03:23 AM on 21 April 2012
       Why Are We Sure We're Right? #1
       Glenn Tamblyn has it right. Confirmation of our understanding of complex systems is based not on one empirical finding but on many different findings that are consistent or at least have not found to be mutually inconsistent--a kind of triangulation. So, anyone who rejects AGW must present an explanation that offers alternatives to well-established physics and chemistry--something that you never see from the deniers. Marsupial's comments are okay but for heaven's sake do not cite David Hume, the causality denier, in support of science or scientific thinking.

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