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Comments 106401 to 106450:

106401. Doug Bostrom at 21:02 PM on 20 October 2010
        It's not bad
        i propose that the rainforest and the sea are far away from westerners who comment on this site. Illustrating the hazards of assumptions, we live about 5 miles as the crow flies from the sea, about 40 miles from a temperate rain forest.
106402. hapivibe at 20:54 PM on 20 October 2010
        It's not bad
        cool doug and dappled. i feel better that it's not just words xx ahhh!!!please, no kisses on this site, it's for proper scientists don't you know! scientists need love too : - ) ?
106403. Doug Bostrom at 20:48 PM on 20 October 2010
        It's not bad
        Well, hapivibe, to me "would have thought" sounds kind of like "assume." We all know what "assume" means. I can tell you that in my case we have a bit of computer gear here that necessarily runs all the time, having to do w/offsite backup. Problem, eh? Especially it's a problem because while the local climate means that a little less than 90% of our juice comes from hydro, the same climate means that photovoltaic systems are not affordable for much more than crosswalk flashers and things on that scale. What does work here is domestic hot water preheat via solar collectors, so I installed a system that eliminates a substantial amount of electrical input for hot water heating, thus indirectly eliminating about twice the electricity consumed by the 24/7 computer hardware. What's great about the DHW thing is the knock-on, catalytic effect it had on some of our other behaviors around the house. The absolute consumption (~1000kWh/year) of the computer hardware versus the DHW output reminded us of how just a few extra things turned off add up over time. In my mind, turning off unnecessary load sort of equates to more sunlight on the solar collectors. Strange, but that's psychology. Meanwhile, this next couple of years will be most interesting because we've got two automobiles that are arguably ready for retirement. They've reached 20+ years of age and while they're in good repair and don't have the lousiest gas consumption, we're finally at the point where buying an electric vehicle is no longer going to be a technology application experiment folded into day-to-day living. Given our typical requirements for driving, this means we'll shortly no longer have to purchase gasoline except in those rare instances when we decide to rent a IC car for road trips. A big win there. That leaves as usual the problem of air travel, the huge, airy elephant in the room. This is a nice example of how we're embedded in context and the dilemmas that can pose. While many of my relatives in the U.K. are dead, some are not. They are sort of a case of an "endangered species" but all the same I have qualms about visits. We go over that way about every 3 years on average, which is definitely not sustainable when we generalize and consider the hundreds of millions of aging aunts and the like pining for visits from nephews, grandchildren, etc. That's a toughie, it's an inheritance and difficult to just turn off.
106404. hapivibe at 20:47 PM on 20 October 2010
        It's not bad
        hi jurphy thanks for getting back to me and thanks for your interest: i think the smoking analogy has gone off topic a bit so i wont reply directly to that i propose that the rainforest and the sea are far away from westerners who comment on this site. species extinction does not affect us directly nor are we told when we are consuming more than our fair share and it is sadly only a minority of people take direct action to change things. global warming is a more frightening concept as it may affect all of us indiscriminately and therefore is has captured the imagination of people as an issue and it may get more media coverage due to this pscychological aspect than the other issues i proposed. I have no data. I am telling you what i see but i hope you will allow me to write what i see as it doesn't say all comments must be backed up by data anywhere on this site, does it?
106405. Rob Painting at 20:37 PM on 20 October 2010
        It's not bad
        Hapivibe @ 44 - Also, if fossil fuels are running out, does this timing coincide nicely with the need to reduce the use of fossil fuels? Easily accessible oil may be running out, but there's plenty of coal, tar sands and shale left. Enough perhaps, to turn the Earth into a rather different looking planet. Finally, I would love an assurance that the people on this site putting masses of effort into collating data and facts actually live in a sustainable way ie. you practice what you profess Yup, but by no means an "eco-saint". It's a very long list of practices my wife and I undertake to reduce our carbon output, but I don't judge others badly because they don't put in the same effort. Hopefully we'll all get there in the end (fingers crossed!)
106406. Roger A. Wehage at 20:36 PM on 20 October 2010
        Record snowfall disproves global warming
        I believe that here is an excellent example of what John is describing related to temperature effects on snowfall. Below is a plot of the annual snowfall in Houghton, Michigan listed in tabular form on the above website.

        From Climate Change

        Houghton's snowfall is primarily influenced by moisture from the lake (lake-effect snow) and temperature. The graph clearly shows three trends, a relatively constant annual snowfall from 1890 to around 1935, an increasing annual snowfall from around 1935 to around 1980, and decreasing annual snowfall from around 1980 to 2010. I don't have access to average annual winter temperatures, but it is likely that average winter temperatures were colder between 1890 through the 1930s and have been rising steadily until today. Assuming the above, then during the colder years from 1890 to the 1930s the lake likely froze over earlier and thawed later, allowing less moisture to evaporate into the air and reducing lake-effect snow. From the 1930s to around 1980, as winter temperatures increased, the lake started to freeze over later and thaw earlier, allowing more moisture to evaporate, which increased lake-effect snowfall. After around 1980, as temperatures continued to rise, more of the moisture was likely falling as rain, so the average annual snowfall started decreasing again.
106407. RSVP at 20:30 PM on 20 October 2010
        Throwing Stones at the Greenhouse Effect
        Graham... "greenhouse effect slows down the radiative transfer through GHGs re-radiating LWR" IR travels at the "speed of light", some 3 x 10E8 meter per second. Maybe you can explain where the delay is coming from? More relevant to what you mention, you can model the spinning Earth as getting hit with a heat pulse. Temperature rises and falls. Your CO2 affecting the droop, such that it doesnt get as low with less CO2. Miraculously, even though temperatures during the year can get far below zero, somehow due to this process energy is mysteriously accumulating. If so, it can only be doing so in the materials that do not emit IR, not in those that do. AGW depends on this pin ball machine model where the IR is bouncing around as if lost and unable to escape. I believe warming is happening, but I do not believe it is happening for the reasons you do. For this I must be burned at the stake for "throwing stones".
        Moderator Response: The delay is simple to explain, so simple that I believe you already understand it but refuse to stop digging. However, for the sake of completeness, the delay is the same as in any journey - if you take a detour or backtrack, the journey takes longer. The difference between direct radiation into space and radiation that eventually reaches the same place having bounced around our atmosphere a bit first is the measure of that delay. The rest of your post is of a standard consistent with your first, and I decline to indulge your contrarianism any further.
106408. JMurphy at 20:19 PM on 20 October 2010
        It's not bad
        hapivibe wrote : "I know the issues are not mutually exclusive - I am proposing that they get overshadowed." And what is the basis for your proposal ? In what way do you think those issues are being overshadowed ? Is money, effort, etc. being taken away from those issues in some quantifiable way ? What's your evidence ? By the way, my previous analogy of the doctor telling you about cancer or the health-damaging effects of smoking (while being a smoker him/herself) did not involve HIM/HER having lung cancer - it involved them telling you about the detrimental effects on your life from smoking, especially if it had caused YOU to develop cancer. Would you ignore/disregard that doctor's opinion or diagnosis just because that doctor was doing something that he/she is advising you not to (anymore) ?
106409. hapivibe at 20:05 PM on 20 October 2010
        It's not bad
        Hi dappled water I know the issues are not mutually exclusive - I am proposing that they get overshadowed.
106410. Rob Painting at 20:03 PM on 20 October 2010
        It's not bad
        Hapivibe @ 44 - Destruction of the rainforest which is needed for species diversity Destruction of the rainforests will also negatively impact the climate. The Amazon alone has between 86 to 93 billion tonnes of carbon locked up in it's vegetation and soils. Our oceans are being overfished And acidified too, from the combustions of fossil fuels. Which will affect fish populations at some point. So, as you can see, these issues aren't mutually exclusive.
106411. hapivibe at 20:01 PM on 20 October 2010
        It's not bad
        Hi to JMurphy: I would be pretty miffed if my doctor had lung cancer and continued to smoke. to doug_bostrom the amount of activity this site has means that people are really bothered by this issue(s) and I would have thought that people would want to take further, bigger action towards sustainablility than just writing on web site and I am wondering if this is the case.
106412. Doug Bostrom at 19:54 PM on 20 October 2010
        It's not bad
        Witnessing myriad discussions focusing on whatever shreds of countervailing evidence are available as alternative explanations for what is at root a fairly simple, bulky and ultimately powerful process leaves me completely unsurprised that you find discussions here dominated by minutiae, hapivibe. Bloating the importance of little things by employing large rhetoric is the sharpest tool in the kit of people who for whatever reason wish to ignore the CO2 problem. You're absolutely right that we're imposing a heavy load on the systems we depend on. Getting a grip on the CO2 problem is a key part of not further exacerbating our failure to account for our impact on the planet. More, there's little reason to believe that solutions to the problems you mention are somehow mutually exclusive, rather it's probably reasonable to suggest that integrated approaches would be more beneficial. As you suggest, apathy is our enemy, an old human failing seemingly only overcome in moments of crisis. Looking at the various graphs of depressing facts, what's the largest contributor to fossil fuel GHG emissions? Coal is the most abundant and presently active feedstock for CO2. There's plenty of coal and we're burning more of it than ever. We're not going to run out of coal fast enough to rely on depletion of fossil fuels as a solution to CO2 emissions. There's no data so far indicating we're going to stop burning coal. Depletion as a solution to CO2 emissions on the timescale of concern here seems a dead-end. Your demand for assurances about sustainable living is of course impossible to answer affirmatively, either for "the people on this site" in general or you yourself. In communicating via this site you and I and the rest of the gang here are employing a myriad of devices and systems that are not presently built or operated in a sustainable way. What some of us may be able to say is that we try to be mindful of those occasions as are available-- in the context we find ourselves living-- which afford choices regarding making more or less of a mess. Come to think of it, your demand for pledges of sustainability is rather curious. What is it that you think "people on this site" profess? I'm wondering, do you believe that subscribing to mainstream physics and the scientific method in general is some sort of statement of moral superiority? Perhaps I misunderstand, though.
106413. JMurphy at 19:45 PM on 20 October 2010
        It's not bad
        hapivibe wrote : "Finally, I would love an assurance that the people on this site putting masses of effort into collating data and facts actually live in a sustainable way ie. you practice what you profess." Why ? Would you disregard the opinion or diagnosis of a doctor who smokes, especially if you were being told that your cancer was caused by smoking ? Or if you were told to give up smoking because it is badly affecting your health ?
106414. hapivibe at 19:10 PM on 20 October 2010
        It's not bad
        The amount of debate an attention to minutiae is unbelievable on this site. It is good in a way but I am curious as to why the issues on this site evoke more discussion than almost anything else I can think of. The possible downsides to this arguing about AGW/climate change are that it overshadows other very important issues that affect people and planet. Other issues that are important irrespective of AGW are: Destruction of the rainforest which is needed for species diversity Our oceans are being overfished We use too much of the world's resources on average per person Species extinction Political apathy resulting in necessary change not happening quickly enough Also, if fossil fuels are running out, does this timing coincide nicely with the need to reduce the use of fossil fuels? Finally, I would love an assurance that the people on this site putting masses of effort into collating data and facts actually live in a sustainable way ie. you practice what you profess.
106415. HumanityRules at 18:44 PM on 20 October 2010
        Do critics of the hockey stick realise what they're arguing for?
        51.dana1981 Thanks for the condescending reply but at least it directed me to some useful info which was what I really wanted. http://www.ipcc.ch/pdf/assessment-report/ar4/wg1/ar4-wg1-chapter2.pdf So this basically confirms what I said was correct. From section 2.8.5.3 (Efficacy and Effective Radiative Forcing - Solar) "These studies have only examined solar RF from total solar irradiance change; any indirect solar effects (see Section 2.7.1.3) are not included in this efficacy estimate." Section 2.7.1.3 rates the scientific understanding of some of these possible indirect effects as low and very low. Let's not mention what the Haigh paper might do to all this. The incorrect statement here is your suggestion that we can't have it both ways. Having it both ways is still an option until we fill the gaps in our knowledge. Which is all I've been arguing here. I thought the concluding statement about volcanic RF in section 2.7.2.2 was also enlightening. "Because of its episodic and transitory nature, it is difficult to give a best estimate for the volcanic RF, unlike the other agents. Neither a best estimate nor a level of scientific understanding was given in the TAR. For the well-documented case of the explosive 1991 Mt. Pinatubo eruption, there is a good scientific understanding. However, the limited knowledge of the RF associated with prior episodic, explosive events indicates a low level of scientific understanding" I wonder just how many bold staements one can make on this subject.
106416. RSVP at 18:32 PM on 20 October 2010
        Throwing Stones at the Greenhouse Effect
        gpwayne #72 "no interest in" (facts) Would you be just a little concerned if the fan on your CPU died? Why isnt radiation sufficient to cool that big chip? Or if you happen to burn you finger, why not just point it skyward? No, you put it in water because the fact is, convection provides a faster channel to dump energy. Our lives are governed by facts, even if we are successful living off of hype.
        Moderator Response: [Graham] Your straw argument does not pertain to climate change or the planet's energy budget, primarily because it is the current speed with which equilibrium is reached that determines the acceptible limits of our climate (acceptible being what we are used to, what we humans have come to depend on, what we know sustains our agriculture etc). The absence of convection does not preclude heat transfer by radiation, in the same way the absence of water vapour does not inhibit the movement of LWR through a gaseous medium such as a mixture of oxygen and nitrogen. The speed of the transfer is, in fact, the point at issue, because the greenhouse effect slows down the radiative transfer through GHGs re-radiating LWR at specific wavelengths in random directions, thus impeding the direct transfer of heat back to space.
106417. kdkd at 18:27 PM on 20 October 2010
        Do critics of the hockey stick realise what they're arguing for?
        chriscanaris #56 The risk is that if we make unwarranted assumptions that a number is large and negative, if it's small, or positive then we will end up basing policy on a false premise. If you don't want to be seen to be trotting out unsupported climate sceptic talking points, then you need to be more careful in the way that you express yourself ;).
106418. chris1204 at 18:16 PM on 20 October 2010
        Do critics of the hockey stick realise what they're arguing for?
        kdkd: 'Your strategy suggesting that we should account for this unobserved large negative feedback mechanism would seem unnecessarily risky...' What's the risk? '...assuming that it might provide a get out of jail free card seems unwarranted.' Who said it was get out of gaol free card? Not me.
106419. Joe Blog at 18:01 PM on 20 October 2010
        Throwing Stones at the Greenhouse Effect
        KR at 15:06 PM on 20 October, 2010 Yes, it is proof of a transition, not of the greenhouse effect itself. Im a believer in accuracy in these things is all. Its not my call end o the day. But it seems a simple alteration, to: evidence of an enhanced greenhouse is etc... as e said. But ill say no more on the matter ;-)
        Moderator Response: [Graham] Joe - I too think your point is valid and accurate, but it does seem to me a rather arcane point for the basic version. I always struggle with these posts, trying to walk the fine line between brevity and over-simplicity. In this case, since the distinction is clearly addressed in the intermediate version and I can't figure out how to qualify my remark without expanding into more explanations (and qualifications) I've elected to leave it as it is. I do acknowledge your comment however, and agree you are strictly correct.
106420. Jeff Freymueller at 17:31 PM on 20 October 2010
        Increasing southern sea ice: a basic rebuttal
        #8 HumanityRules, for starters, refer to Is Antarctica losing or gaining ice? at another page on this site. And then remember that the Wingham et al paper figures are for ice in the interior 72% of the ice sheet and not at the coastline, which is where by far most of the mass loss occurs (from the second page of the paper: "we extend an earlier survey (Wingham et al. 1998) in space to within, on average, 26 km of the ice sheet margin"). So the "throw away line" is correct, and your position reflects where things stood some years ago, not today.
106421. gpwayne at 17:00 PM on 20 October 2010
        Throwing Stones at the Greenhouse Effect
        Well, The Inconvenient Skeptic expressed some dismay at the entire thrust of the rebuttal, saying "I am not aware of anyone saying there is no greenhouse effect... This article seems intentionally written to insult people that disagree with the theory that the currently increasing CO2 is going to significantly alter the Earth's climate." So I am obliged to RSVP for providing evidence that, far from this being some kind of intentional - and fictitious - slight aimed at skeptics, even on this site we are obliged to address posters who don't understand the greenhouse effect, energy budgets, radiation, heat transfer or the role of GHGs - while these same posters feel they are able to take issue with the scientific complexities of AGW. Thanks also to those more patient than myself, who took the time to explain some basic facts to a poster I suspect has no interest in them (to judge by the amount of time he spends here, and how little he has absorbed while doing so).
106422. HumanityRules at 16:58 PM on 20 October 2010
        Increasing southern sea ice: a basic rebuttal
        I know this is mainly about sea ice but the throw away line about land ice has to be countered. Wingham et al in 2006 found the land ice mass balance increasing 1992-2003. http://www.cpom.org/research/djw-ptrsa364.pdf In fairness my own position would be that antarctic data is so short term, sparse and difficult to interpret that it seems foolhardy to make any sort of definitive comment about antarctic land ice trends. This 2007 Science review by the same authors is well worth a read if you want to get some perspective. http://www.ucl.ac.uk/es/department/news/2007/wingham-science.pdf
106423. kdkd at 16:05 PM on 20 October 2010
        Do critics of the hockey stick realise what they're arguing for?
        so there's clearly a good reason to study the role of clouds in forcing feedback, but assuming that it might provide a get out of jail free card seems unwarranted. That is all.
106424. kdkd at 16:04 PM on 20 October 2010
        Do critics of the hockey stick realise what they're arguing for?
        chriscanaris #52 All I'm saying is that making strong conclusions about cloud feedbacks, and climate risks is unwarranted from that paper. Meanwhile the bulk of the information available to us suggests that any negative feedback from clouds won't be big enough to remove the anthropogenic forcings. Your strategy suggesting that we should account for this unobserved large negative feedback mechanism would seem unnecessarily risky
106425. chris1204 at 15:53 PM on 20 October 2010
        Do critics of the hockey stick realise what they're arguing for?
        Phila @ 50: I'm not saying, 'Things won't be that bad.' I'm saying, 'There are many things we don't know which we really need to know.' I certainly think what we know is sufficient to warrant action and I have said so often enough. In my professional life, I'm no stranger to the need for decisive action in the face of major uncertainty. I have to explain this uncertainty to people - indeed, if I failed to do so, I would expose myself to a malpractice suit. Moreover, I prefer being honest with my clientele (it actually feels better doing things that way). At the same time, I certainly want to know more whether it's in my professional life or in an area of interest.
106426. alan_marshall at 15:52 PM on 20 October 2010
        Throwing Stones at the Greenhouse Effect
        If some skeptics were right in claiming the greenhouse effect had indeed been falsified, then that would apply to the greenhouse effects of water vapour and methane as well as CO2. Sorry to point out the obvious, but any high school kid can demonstrate the greenhouse effect of water vapour simply by correlating overnight minimum temperatures with cloud cover. An example of this simple exercise is provided on my web site (www.climatechangeanswers.org/science/homedemo.htm). (My apologies to the better informed skeptics, but outright denial of the greenhouse effect has to dealt with forcefully)
106427. chris1204 at 15:38 PM on 20 October 2010
        Do critics of the hockey stick realise what they're arguing for?
        kdkd: Wide error bars arise because of limited information. Do you prefer making decisions based on limited information by artificial foreclosure or would you prefer informed decision making in the context of acknowledgement of uncertainties? Would you rather everyone decided to treat clouds as an inconvenient distraction or would you prefer to see climatologists striving to understand their role better? Eyeballing the AR4 graphic, the cumulative aerosol and cloud albedo effect even *without* the error bars actually approaches the CO2 effect. This is not trivial. The size of the error bars in this context highlights the urgency of the need for better data and better understanding.
106428. dana1981 at 15:34 PM on 20 October 2010
        Do critics of the hockey stick realise what they're arguing for?
        Humanity Rules #40 - I suggest you do some reading on efficacies of different forcings. The aforementioned (and linked) climate sensitivity rebuttal is a good starting point.
106429. alan_marshall at 15:28 PM on 20 October 2010
        Throwing Stones at the Greenhouse Effect
        In your rebuttal it might be worth adding that, as Tyndall and others have proved in the laboratory that CO2 absorbs infrared radiation, the onus is well and truly on the skeptics to prove that CO2 behaves differently in the atmosphere. This is how I worded it on 22 Sep 2010 in my article Climate Change: The 40 Year Delay Between Cause and Effect: "There should be no dissent that CO2 absorbs infrared radiation, because that too has been demonstrated in the laboratory. In fact, it was first measured 150 years ago by John Tyndall using a spectrophotometer. In line with the scientific method, his results have been confirmed and more precisely quantified by Herzberg in 1953, Burch in 1962 and 1970, and others since then. Given that the radiative properties of CO2 have been proven in the laboratory, you would expect them to be same in the atmosphere, given that they are dependent on CO2’s unchanging molecular structure. You would think that the onus would be on the climate skeptics to demonstrate that CO2 behaves differently in the atmosphere than it does in the laboratory. Of course they have not done so."
106430. TOP at 15:20 PM on 20 October 2010
        Throwing Stones at the Greenhouse Effect
        @DSL Very good point. "Seriously, take a little time off and study radiative transfer and what happens to incoming solar radiation when it hits the various surfaces of the earth system." The albedo of the ocean is microscopic when compared to the land or clouds. In other words the ocean absorbs almost all the radiation that hits it. So what keeps it so cool? Water is the ultimate greenhouse liquid. There are minor forcings to this effect like plankton, wind and the angle of the sun's rays. Most likely it is not radiation back into space, it is evaporation (phase change) and convection. The heat is re-radiated into space from the upper levels of the atmosphere when the water vapor changes phase back to water. That's why you can see the tracks of hurricanes in the ocean surface temperatures for a time after a hurricane passes. Mess with evaporation and you really do have a problem.
106431. Phila at 15:18 PM on 20 October 2010
        Do critics of the hockey stick realise what they're arguing for?
        chriscanaris: I'm not into bargaining (and by implication, denial). I'm getting weary of repeating that I believe rising CO2 very likely heralds warming and that our society should aim to decarbonise. Bargaining doesn't imply denial, as I see it. It implies a preliminary acceptance of a situation, coupled with an unwillingness to face the full implications of that situation. My impression is that you keep saying, in effect, "maybe things won't be all that bad," without offering much in the way of a cogent defense for that position. Again, uncertainty in itself does not provide rational grounds for optimism. Furthermore, I suspect that the scientists who are counseling immediate action actually have a far better grasp of the relevant uncertainties than dilettantes like you or me. Recognizing what we don't know is important, granted. But recognizing what we do know is important, too. Waiting for the science to get "better" is a pretty irresponsible gamble, IMO, especially given that the plausibility of AGW being much less serious than we think seems to rise in inverse proportion to one's actual expertise.
106432. KR at 15:06 PM on 20 October 2010
        Throwing Stones at the Greenhouse Effect
        Joe Blog - Actually, having less energy leaving than arriving is exactly what is happening. The various feedbacks and systems (ocean temperatures, in particular) have a time lag to changes in forcings, and are still approaching equilibrium. While that is occurring, there will be a net imbalance at the top of the atmosphere. The climate doesn't react instantly - there's always a lag to respond to forcing changes. And positive feedback doesn't indicate a runaway situation unless the gain is >1, as has been repeated discussed here.
106433. kdkd at 15:04 PM on 20 October 2010
        Do critics of the hockey stick realise what they're arguing for?
        Chris #47 For prudence, one should take the midpoint of a value between error bars for your estimated parameter value, unless there's good evidence to suggest that the error bars are somehow wrong. In which case the error bars should be revised to be narrower. Unless there's assessment of greater uncertainty. As a good guess, one should take ±1SD of the error bars as being 66% likely and ±2sd as being 95% likely, with ±3 SD as being 99.8% likely. Attempting to draw strong conclusions by assuming that the true value is between -3 and -2 SD (approx. 17% likely = (99.8-66/2) ) is a fools errand. This appears to be what you're doing. The paper you referred to was merely indicating that the current estimate of the size of the error bars is very wide, which is an entirely different proposition.
106434. alan_marshall at 15:02 PM on 20 October 2010
        Do critics of the hockey stick realise what they're arguing for?
        An excellent article, John. Confronting skeptics (who won’t listen) and the general public (who may listen) with the logical consequences of skeptics’ claims is potentially an effective alternate line of rebuttal. I don’t think you need to complicate the article by discussing the evidence for a global or local MWP. The global temperature reconstructions in Ned’s article posted on 28 Sep 2010 are broadly in line with the reconstruction you have used here, so your argument still holds. The climate sensitivity to a particular greenhouse gas (CO2, CH4 or whatever) is the temperature rise resulting from a doubling in concentration of that greenhouse gas. The value of the radiative forcing corresponding to the doubling is not part of the definition. Your wording: Technically, climate sensitivity is defined as the change in global temperature if the planet experiences a climate forcing of 3.7 Watts/m2 (which is how much climate forcing you get from a doubling of CO2). Suggested alternate wording: Technically, climate sensitivity is defined as the rise in average global temperature resulting from a doubling of atmospheric CO2. (The added radiative forcing from such a doubling is 3.7 Watts/m2.) The text “then current climate change must also also natural” should read ““then current climate change must also be natural”.
106435. e at 15:01 PM on 20 October 2010
        Throwing Stones at the Greenhouse Effect
        Joe, I think you make a valid point, but consider that this post is meant as a "basic" version of the argument. Technically speaking, the short term decrease in outgoing radiation is evidence of an enhanced greenhouse effect, not a greenhouse effect in general. It's an important distinction to make, but I think it's a bit too pedantic for a basic version of the post. If you take a look at the intermediate version of this post, you will notice that this distinction is spelled out more explicitly.
106436. chris1204 at 14:56 PM on 20 October 2010
        Do critics of the hockey stick realise what they're arguing for?
        kdkd: The whole point of the paper is that there is a lot we don't know and a lot we need to find out. Recognising the limitations of our knowledge is the sine qua non for progress in science. AR4 however does provide an estimate of cloud and aerosol feedbacks relative to other forcings including an estimate of uncertainties for both cloud, aerosol, and CO2 forcings. While I don't regard AR4 as the Holy Grail of climate science (there is no such thing in any science), I think it's a reasonable starting point.
106437. Chris G at 14:20 PM on 20 October 2010
        Increasing southern sea ice: a basic rebuttal
        This might belong under the intermediate version, but thinking of the complexity... It's pretty clear that less ice in the winter, (as mentioned in the article), when it's dark, would have negligible warming effect because albedo doesn't play a factor when it's dark. However, to add to what GT just wrote, if there is more ice at the beginning of the melt season, I'm thinking that will be a negative feedback to regional warming. I'm not saying it will be stronger than the other effects; I'm just thinking it will exist and wondering how it will all add up.
106438. kdkd at 14:18 PM on 20 October 2010
        Do critics of the hockey stick realise what they're arguing for?
        chriscanaris #45 Without wading through the detail of the Stephens 2005 paper, it doesn't seem to be offering any information on the order of cloud feedbacks relative to other climate forcings. As a result the paper quite rightly does not offer strong conclusions about the sign and magnitude of climate sensitivity itself, but defers this to other literature. From looking at the paper, it does not offer any justification of the strong claims that you are trying to make.
106439. Joe Blog at 13:52 PM on 20 October 2010
        Throwing Stones at the Greenhouse Effect
        "This 33C worth of energy in transit in the atmosphere is the proof. " This average increase of 33C at the surface as a result of energy in transit through the lower atmosphere is the proof... being pedantic again.
106440. Same Ordinary Fool at 13:41 PM on 20 October 2010
        Increasing southern sea ice: a basic rebuttal
        Ldavids = Larsen B ice shelf pieces did become 'sea ice' after they broke off. Before that, as a floating ice shelf they were still attached and considered land ice. Yours is the first mention I've heard of the interesting idea of possible changes in the thickness of Antarctic sea ice. There aren't any multi-year issues, as in the Arctic. But have there been any changes in Antarctic sea ice thickness from year to year? Sigmond and Fyfe(2010) have apparently taken away the simpler to express, "its the ozone hole" explanation for the recent increases in Antarctic sea ice. So now we really will have to learn the much more complicated density/salinity/stratification/warmer-Southern=Ocean story.
106441. chris1204 at 13:24 PM on 20 October 2010
        Do critics of the hockey stick realise what they're arguing for?
        kdk @ 43: See the excerpt from the Stephens 2005 abstract as above. I think this deals with your questions (2) & (3). If you want to scrutinise the paper itself, there's no paywall :-).
106442. Joe Blog at 13:22 PM on 20 October 2010
        Throwing Stones at the Greenhouse Effect
        Sorry, but im going to have to reiterate my objection to this part of the last paragraph: "The most conclusive evidence for the greenhouse effect – and the role CO2 plays – can be seen in data from the surface and from satellites. By comparing the Sun’s heat reaching the Earth with the heat leaving it, we can see that less long-wave radiation (heat) is leaving than arriving" This is unphysical, no two ways about it, if it were true we would be heading for the Temperature of the surface of the sun. It is disingenuous to try and cure a misconception, with another misconception. By comparing incoming energy, vrs outgoing,vrs thermal capacity of the surface, you can determine that the average T should be -18C... But its not, that is the proof of the GHE. The fact that the average T is 15C. This 33C worth of energy in transit in the atmosphere is the proof.
106443. adelady at 13:21 PM on 20 October 2010
        Increasing southern sea ice: a basic rebuttal
        John, remember the pure water melted from the land ice has a freezing point of 0C, (and of precipitation in the form of rain and snow). The freezing point of sea water varies but it's usually around -1.8C. Philippe's remark about salinity and stratification is the key.
106444. chris1204 at 13:16 PM on 20 October 2010
        Do critics of the hockey stick realise what they're arguing for?
        angliss @ 42: Your point about modelling in relations to period of rapid transition valid. However, as I understand it, the uncertainties extend well beyond this issue. From the abstract of the Stephens 2005 paper: '...What emerges is the importance of being clear about the definition of the system. It is shown how different assumptions about the system produce very different conclusions about the magnitude and sign of feedbacks. Much more diligence is called for in terms of defining the system and justifying assumptions. In principle, there is also neither any theoretical basis to justify the system that defines feedbacks in terms of global–time-mean changes in surface temperature nor is there any compelling empirical evidence to do so. The lack of maturity of feedback analysis methods also suggests that progress in understanding climate feedback will require development of alternative methods of analysis. It has been argued that, in view of the complex nature of the climate system, and the cumbersome problems encountered in diagnosing feedbacks, understanding cloud feedback will be gleaned neither from observations nor proved from simple theoretical argument alone. The blueprint for progress must follow a more arduous path that requires a carefully orchestrated and systematic combination of model and observations. Models provide the tool for diagnosing processes and quantifying feedbacks while observations provide the essential test of the model’s credibility in representing these processes. While GCM climate and NWP models represent the most complete description of all the interactions between the processes that presumably establish the main cloud feedbacks, the weak link in the use of these models lies in the cloud parameterization imbedded in them. Aspects of these parameterizations remain worrisome, containing levels of empiricism and assumptions that are hard to evaluate with current global observations. Clearly observationally based methods for evaluating cloud parameterizations are an important element in the road map to progress.'
106445. kdkd at 13:13 PM on 20 October 2010
        Do critics of the hockey stick realise what they're arguing for?
        chriscanaris #41 It seems to me that you need to expand on what you mean by your answer to questions 2 and 3, in order to attempt to show that you're making a valid claim. At the moment your answer is an assertion, and is not backed by evidence.
106446. DSL at 13:12 PM on 20 October 2010
        Throwing Stones at the Greenhouse Effect
        It is relevant, John. The problem with the Bible, though, is determining with any degree of precision just when the relevant parts were written. The stories that make up the Bible--even those of the NT--were developed over centuries--perhaps longer. The Jesus stories may be imported from other, earlier cultures (Egypt, Horus--that sort of thing). If you question tree ring proxies, you shouldn't be moving toward the Bible as a proxy. RSVP, if any climatologist had made your claims on this thread, even the folks over at WUwT would be ROFL (ABSTTN - and blowing soda through their noses). Seriously, take a little time off and study radiative transfer and what happens to incoming solar radiation when it hits the various surfaces of the earth system.
106447. adelady at 13:04 PM on 20 October 2010
        Increasing southern sea ice: a basic rebuttal
        Ldavids - volume isn't an issue for sea ice in the Antarctic. There's little to no multi-year ice because it pretty well melts out fully each summer. Volume is only possible in the Arctic because sea ice doesn't melt out every year. Even the record minimum extent in 2007 was caused as much by winds piling the ice up towards the end of the season as it was by melting throughout the season. Unfortunately as extent and volume are steadily decreasing, more ice is melting out by the combination of warm waters from the Pacific and Atlantic and more water movement because of larger areas of open ocean within the Arctic basin.
106448. Philippe Chantreau at 12:25 PM on 20 October 2010
        Throwing Stones at the Greenhouse Effect
        "the quote is using the term green house effect for the specific effects of the so called green house gases, not the green house effect of the atmosphere as a whole." Total nonsense. The atmosphere can not have a greenhouse effect unless GH gases are part of it. This thread is going nowhere fast.
106449. Philippe Chantreau at 12:20 PM on 20 October 2010
        Increasing southern sea ice: a basic rebuttal
        John, salinity and stratification are more likely to have major roles.
106450. angliss at 12:16 PM on 20 October 2010
        Do critics of the hockey stick realise what they're arguing for?
        chriscanaris - I'm not sure that it is an assumption that current models satisfactorily model clouds. Climate sensitivity is an equilibrium value and it has been derived repeatedly using multiple sources of data (not modeling information, actual data) over multiple time periods. The results do vary, but they all have similar ranges that overlap. Given the time scales involved and the fact that climate sensitivity is an equilibrium value, it's probably reasonable to say that climate models likely model clouds sufficiently for equilibrium conditions, given that climate models independently derive ranges for climate sensitivity that are roughly similar (and that overlap) with the empirically-derived values. The question is whether clouds are modeled well enough for periods of rapid transitions. In mathematical parlance, how much do the clouds change the slope of the differential equation in time from the base level of the climate sensitivity? Will they increase or decrease the slope, and by how much?

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