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All IPCC definitions taken from Climate Change 2007: The Physical Science Basis. Working Group I Contribution to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change, Annex I, Glossary, pp. 941-954. Cambridge University Press.

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Comments 54901 to 54950:

  1. Realistically What Might the Future Climate Look Like?
    The big issue, of course, is that addressing the biggest sources of GHG emissions is frequently the most cost effective approach. You get twice the reduction in fuel consumption (and corresponding emissions) by replacing a 15mpg vehicle with a 30mpg vehicle, than by replacing a 30mpg vehicle by a 60mpg vehicle. (Counterintuitive, but true.) Applying this to the social domain, the biggest emissions gains are probably to be made by convincing people who are taking no action to take some action, rather than by convincing those who are already taking action to take more.
  2. Realistically What Might the Future Climate Look Like?
    For what it's worth: I do an 8 mile round trip commute by bicycle every day. I also drive a small diesel car which does 50/75mpg (40/60 US). I fly to scientific conferences when the train is impractical, but complain about it. My house uses less-efficient halogen lighting rather than CFLs because CFLs are a migrane trigger for my wife. I am a hypocrite. The laws of physics remain unmoved.
  3. Realistically What Might the Future Climate Look Like?
    The question of whether I am a hypocrite has no bearing on whether I am right or not. The laws of physics are supremely indifferent to our hypocsrisy. They are what they are.
  4. Realistically What Might the Future Climate Look Like?
    RE#8 Wow, that is most certainly a disheartening comment. I do find it difficult in my own situation in a shared apartment to control my housemates energy behavior. With them often leaving the TV on, or stereo on once music stops, food in the fridge going off, and of course always with the lights on. I have succeeded in convincing them to step up from 10% green power to 25% green power. I think with this recent arctic 2012 low, we will see more 'lukewarmers' appearing.
  5. Realistically What Might the Future Climate Look Like?
    Sphaerica, it's the Al Gore defense. "If Al Gore isn't living in a cave then he doesn't believe in AGW therefore I don't have to believe in AGW or change my behavior in any way." It's a great way to justify continuing the status quo guilt free.
  6. Realistically What Might the Future Climate Look Like?
    You know, I just got this line from someone else on another site. Is it the latest ostrich defense? "If you really believed what you say, you wouldn't needlessly generate CO2 by using the Internet to argue with me. If you really believe in GHGs and AGW, and aren't a hypocrite, you wouldn't even be here right now, and we could all stop listening to you."
  7. Matt Ridley - Wired for Lukewarm Catastrophe
    Joel, What did you misunderstand in my words that led you to believe that I was "arguing that Greenhouse gases are not a primary forcing"? There is no such statement or implication in anything I said. I spoke purely about feedbacks which are non-linear, as well as negative forcings which are (temporarily) masking current GHG forcings. What confused you?
  8. Matt Ridley - Wired for Lukewarm Catastrophe
    Joel - so my graph is misleading because you don't like bar charts? Riiiiiiight. No algorithm? There's one vertical bar per year. If you mean the horizontal bars, they're one per decade. I really don't know how it could be any simpler or clearer. Not sure why you're asking for the data that you've already plotted yourself, but it's here. Still waiting for you to show some skepticism and do that exponential fit.
  9. Matt Ridley - Wired for Lukewarm Catastrophe
    I think debating what curve best fits the co2 emissions so far is missing the main point. The emission scenarios considered by the IPCC are found here. Note in figure 3, that none of the scenarios have a combined emissions that rises exponentially to 2100. It is wrong to claim that the predictions for temperature rise by 2100 is based on exponential emission increase. Feedbacks do that. Furthermore, as far as I know, none of the AR4 models even considered carbon cycle feedbacks as they were considered too slow to have an impact over such a short time frame. The effect of zero carbon and constant carbon emissions have been considered by published papers. These were discussed at Realclimate here.
  10. Matt Ridley - Wired for Lukewarm Catastrophe
    dana1981 @34 . The first problem is the use of a bar chart. Anyone who is familiar with the work of Edward Tufte, will assume that anyone using a bar chart is trying to sell you something, since it is the 2nd worst chart after the pie chart. The 2nd problem is that there is no discernible algorithm for where the vertical bars are drawn. If you have access to the orginal source material, maybe you can post a link? I said 'looks pretty good' because the r-squared is .98, which I included on the graph. I spent a fair amount of my career writing programs to create graphs to support actual engineering decisions and tend to be pretty picky about graphs. I usually download the raw data and draw my own graphs. Wood for trees
  11. Matt Ridley - Wired for Lukewarm Catastrophe
    #37 - comment of the day! Yes, it produces a lower fit, because over the longer period, the concentration of CO2 is more clearly accelerating!. That would be exactly the point. As Dana suggests, what happens if you try an exponential fit?
  12. Matt Ridley - Wired for Lukewarm Catastrophe
    Skywatcher @32 I used 1979, because that is the same date I used for my post @21 for temperature. Using longer intervals actually results in a lower linear fit.
  13. Matt Ridley - Wired for Lukewarm Catastrophe
    Joel - do you understand the difference between a forcing and a feedback? The change is CO2 by use of fossil fuel is the forcing (cause), atmospheric aerosols are negative forcing (but short-lived). Temperature-induced changes to GHG, albedo etc are feedbacks that amplify the forcings, work non-linearly and over very different timescales.
  14. Matt Ridley - Wired for Lukewarm Catastrophe
    Moderator @29 . I think that is actually Sphaerica responsibility. He is the one is arguing that Greenhouse gases are not a primary forcing. I just kicked the ball to the IPCC.
    Moderator Response: [DB] Umm, no. The IPCC is merely a collection/collating body that summarizes the primary literature. It is that selfsame literature that very clearly delineates GHG's as a feedback and forcing. Even skeptics and fake-skeptics such as Spencer, Singer, Lindzen, Evans, Monckton, Jo Nova and Christy acknowledge that.

    (Rob P) - a simple no would have sufficed.

  15. Realistically What Might the Future Climate Look Like?
    Dale, what you are suggesting (individual effort) will, in the absence of effective society-wide efforts, lead to collective action problems and, most likely, eventual failure. Revolutionary changes to entrenched socioeconomic systems aren't going to happen without substantial institutional and other reforms.
  16. Realistically What Might the Future Climate Look Like?
    Speaking of leading by example... So...where's Dale's Starfish?
  17. Realistically What Might the Future Climate Look Like?
    Dale @2, I do lead by example. Can I now expect you to follow suit?
  18. Realistically What Might the Future Climate Look Like?
    Dale, frankly that is what I and many others do. However, looking at many of my fellows, I doubt very much that they will follow me. I have trouble getting my children to take navy showers. MacKay's "Sustainable Energy without all the hot air" (available online) gives you a pretty good indication of the limits of what an individual can do. A better solution is an alternative energy structure and that is not done by individuals. Suppose you simply banned the creation of new coal power plants. No immediate impact but you have to have a plan for how to replace old stations. All other kinds of electricity generation are available. The best technology will come to fore without any other government intervention simply from market demand. Of course, a government decree like that is unacceptable in many parts of the world (not in NZ however), so instead expensive and inefficient schemes like carbon tax or trading schemes are required to have the same effect.
  19. Realistically What Might the Future Climate Look Like?
    Climate ostriches like you ignore the fact that this very forum is leading by example by its existence. Despite the continual trolling by deniers. Might I suggest putting your actions where your mouth is and start being part of the solution instead of being part of the ostrich herd?
  20. Matt Ridley - Wired for Lukewarm Catastrophe
    Joel @28 - I'm not really sure how to respond to your comment. How do you propose the chart I provided is "misleading" in any way? You seem to suggest it's misleading because a linear fit "looks pretty good" (ah yes, the ever reliable Eyecrometer). That's nice - did you try an exponential fit? If not, you're not being a skeptic - you're trying to justify your pre-determined conclusion instead of trying to find the right conclusion. Until you can accept the reality of accelerating CO2, it seems like a complete waste of time to continue this discussion. Sorry I'm being a little cranky, but I really don't appreciate being called misleading for presenting a very simple and clear graph to prove my point.
  21. Realistically What Might the Future Climate Look Like?
    If the call is "that we keep doing everything we can do to reduce our emissions as much as possible in order to avoid as many catastrophic consequences as possible, for the sake of future generations and all species on Earth", then may I suggest that the best way to start is to lead by example. Instead of constantly decrying the World for not acting, take the challenge and eliminate your GHG emissions totally. Take the bull by the horns, lead by example, show the world how it's done. To be taken seriously, you need to lead.
  22. Matt Ridley - Wired for Lukewarm Catastrophe
    "half" should, in fairness, read "just over half"...
  23. Matt Ridley - Wired for Lukewarm Catastrophe
    #28, why would you want to use half the Mauna Loa data to fit your trendline? Why not use all of it? The source of the graph is this post by Tamino. There's also a plot of the rate of increase. How does the rate of increase look over the longer timeframe - the rate is increasing, which means that CO2 output is in fact accelerating. This increase is present in your graph, but it's small because of the shorter timescale. Now we know why you only wanted to use data from about 1980... Also worth watching is this animation of CO2 increase (youTube video by Robert Way, data from NOAA). Pause the video at 1:27, see if you still contend that there has been no acceleration (assuming you can dislike Tamino's statistical analysis). Run the video on to the end, and then ask yourself what the apparently small wiggles appearing from the bottom left correspond to in terms of Earth climate changes. Still think the change is small? Plotting small, out-of-context snippets of data is a good way to fool yourself.
  24. Matt Ridley - Wired for Lukewarm Catastrophe
    Joel@29; you're correct, and all available science supports that CO2 *is* the primary driver in this scenario. This is a seminal paper, and if you'd like more (e.g., being a true skeptic and not a denialist) I, and others here, can easily supply you many, *many* other peer-reviewed and very robust papers saying the same. CO2 Is The Principal Control Knob
    Moderator Response: [DB] Fixed text and link. The lecture version is here.
  25. Matt Ridley - Wired for Lukewarm Catastrophe
    We should implement strict rationing, because it's going to happen anyway. Better we should impose it, according to the Post Carbon Institute: http://www.youtube.com/watch?feature=player_embedded&v=4uKgU7krWzE
  26. Arctic sea ice breaks lowest extent on record
    Anyone seen any animations showing perennial sea-ice? Something like the video here except showing the recent events
  27. Realistically What Might the Future Climate Look Like?
    In an utterly selfish way, when I first began looking into this issue (ca. 1990) and some predictions somewhat mirrored this one, I pooh-poohed it. Couldn't possibly be viable. We're too small to make these changes to our giant world. Aha. By 2000, I no longer rejected the science, but (and here's the selfish bit) I was pretty well convinced I'd be long dead before this all came to pass. Given I am a 1957 model, it begins to look more and more likely I *could* see some of these deleterious effects. strictly for my own self, i am glad I chose to not have kids but that in *no way* obviates my fears for those I will leave behind. I guess that is what drives me to ~distraction~, listening to the deniers' throw roadblocks (and let's be *very* clear: they ahve been insanely successful in their blocking maneuvers) up to making progress on this. We have wasted 20+ years, years that could've gone so far towards drawing down our collective carbon footprint. I'm truly alarmed, and saddened. Dana, once more let me be one to thank your for your tireless efforts to counter this; in my 'geologist's hat,' I'm doing all I can to try to trim tab this ship, towards a rational, sane future. Your posts (and all others here) go a long way to helping me do just that.
  28. Matt Ridley - Wired for Lukewarm Catastrophe
    Sphaerica @26. That is something you really need to take take up with the IPCC. They are the ones that insist that Greenhouse gases are the primary source of climate warming.
    Moderator Response: (Rob P) - before you venture into sloganeering territory. Can you provide any peer-reviewed scientific literature that explain the suite of observations as well as the concentration of greenhouse gases in the atmosphere? A simple yes or no will suffice.
  29. Will the Wet Get Wetter and the Dry Drier?
    Byron @8 I did much the same as you, stopping the video at various points to better focus on some of the details. I also compared it to Figure 2 of Dai's August 5, 2012 Nature Climate Change letter. There are multiple differences between the two calculations, notably Dai has the drought in the US much worse than the GFDL simulation. The Sahel region is the complete opposite for Dai, he shows increased precipitation. Dai also has the southern part of Africa and the northern part of South America much worse off.
  30. Matt Ridley - Wired for Lukewarm Catastrophe
    dana @24 I am afraid the chart you are using is misleading. I downloaded the CO2 data for the same interval as my temperature chart and plotted a linear trendline and the fit is actually pretty good. There is nothing in the actual C02 data that supports an increase to 792PPM of CO2 by 2000, that would be necessary for a 3 degree increase by your own data. CO2 Chart The actual CO2 data, seems quite consistent with 1-2 degrees of warming by 2100 for 3 degrees per doubling.
  31. Why Arctic sea ice shouldn't leave anyone cold
    A last question: why were monthly ice charts sufficient back "in the day" to enable (relatively) safe surface navigation in Arctic waters? With today's highly mobile, fractionated and dispersed pack, daily updates are sometimes insufficient. Tolkien drew upon a specific source as inspiration for his Helcaraxë...anyone know what that was? Bueller?
  32. Why Arctic sea ice shouldn't leave anyone cold
    SRJ, the other participants have addressed most of this so I will narrow my response to this: You say that the white areas denote no information. While technically true you ignore the context of the charts. As a former (nautical) cartographer (yes, professionally), all mapping products fulfill a singular purpose for which they were specifically designed. The ice charts in question were designed as aids to surface navigation and were compiled from the best available sources at the time. Each month, the originating cartographers produced another version, one for each month of the melt season, year after year. Take the time to look at each month of 1938. Look at other years. Compare the peak melt month (therefore the peak of navigation season), August, of each year to other years (whatthehell, compare any month you want to any same month of another year, but be consistent). What do you see? Variation. The specific months have the ice in red in specific locations with specific condition of the ice specified. But is that the limit of the data contained on each month? No. Compare the white areas. What do you see? The white, "undefined" areas vary, by month and by year. Why do you suppose that is? Those areas were delimited by information, not by guesswork or the conditions of ones entrails. Was it sufficient information to then qualify to be charted in red per the custom? No. But there was information on ice/open sea extent, sufficient to change the portrayals of each month. Whether that information was derived from ships logs, eyewitness testimony or aeroplanes flying overhead is immaterial; they were not derived through clairvoyance. So go ahead, peruse the various months of the various years. Find another ice minimum month which shows ice extent throughout the Arctic anywhere near comparable to that of today. Yes, that's right, I'm inviting you to pick the fake-skeptic's favorite Arctic fruit: iced cherries. Note also that any warming comparable to today's warming would also be causing ice shelf breakups throughout the Canadian Archipelago and Northern Greenland, like that occurring today. If you want a list of papers to hunt through for that evidence, just ask. I'll leave you with this hint, from Polyak et al 2010: "The current reduction in Arctic ice cover started in the late 19th century, consistent with the rapidly warming climate, and became very pronounced over the last three decades. This ice loss appears to be unmatched over at least the last few thousand years and unexplainable by any of the known natural variabilities."
  33. Why Arctic sea ice shouldn't leave anyone cold
    SRJ @70, while I appreciate the need for caveats, Daniel Bailey compared the two maps to directly rebut a claim made by John Christy. The deficiencies of the 1938 map are not so great that the comparison does not rebut Christy. It is a common experience here, and at other sites dedicated to the science of global warming for "skeptics" to make comments suggesting caveats are in order, and treating the need for any caveat, no matter how slight, as a complete rebuttal of the evidence they dislike. I am not in any way suggesting that that was your purpose. Never-the-less, given that you felt it necessary to suggest the caveat, I felt it necessary to point out that the caveat did not in any way rebut DB's point. I cannot, for the life of me, see why you would object to it being made clear that denier misrepresentations of sea ice extent are not supported by the evidence.
  34. Will the Wet Get Wetter and the Dry Drier?
    Rob @5, Indeed I was referring to a possibility (unconfirmed) of permanent El Nino in Pliocene-like conditions. My typo, sorry. Jeffrey @7, Why are you bringing the Challenger disaster to the context of droughts and floods increases? Can you quote what exactly Richard Feynmann had said? I vaguely remember that incident as it was 25+ yago.
  35. Matt Ridley - Wired for Lukewarm Catastrophe
    While others have pointed to some of the non-linearity in feedback system, it is worth also noting a couple of things. 1/ At moment, natural systems mop up more than half our emissions but there is doubt that the sinks can continue to do this 2/ Rising temperatures eventually cause natural increases in CH4 and CO2 from sea, tundra, swamps but this is a slow feedback. Fortunately, we can model these rather than just extrapolate temperature trends. The results arent pretty but that is no reason to ignore them.
  36. Matt Ridley - Wired for Lukewarm Catastrophe
    23, Joel, And what if the system isn't so simple? What if the Arctic ice melt happens abruptly (as if that could ever happen), and the subsequent changes to the Arctic profile (absorbing radiation instead of reflecting it) ramps temperatures up in a sudden bump? And then that bump releases methane cathrates and melts permafrost in large quantities, causing another bump? What if the actual system moves in fits and spurts, bumping temperatures abruptly on timescales that a few decades cannot detect? In short, what if the science that suggests 2.4-4 C warming, based on a variety of disparate methods, is correct, and your simple projection based on a short period of observation is completely wrong? What if aerosols, a quiet sun, and a string a La Nina's are coincidentally and randomly holding warming to just 0.14 degrees per decade, but every down has an up, and there will be decades where the sun is hot, El Nino dominates, and China and other countries get their sulfide emissions under control? What if, as we already know, dimming aerosols provide a negative compensation for the radiative effects of CO2, and once those stop counteracting the GHG effect, a greater, fuller effect of CO2 is felt, well beyond 0.14˚/decade? What if the nice, simple, linear warming we've seen in just the first few decades since aerosols were reduced in the seventies is really just a blip in the process, and that when you add in real feedbacks, like the Arctic, things get more messy? And what if, as this year's extreme weather shows, the actual negative effects of even a small change in climate are far more deleterious than you or others expect, and that even "just" a 1.2 to 1.4 (or 2 or 2.5 or 3) degree increase has very, very frightening consequences? I think the problem with lukewarmers is that they are the worst of the deniers. They want to have it both ways, to accept the science but to be "reasonable" and dismiss any part of it which requires actual action. As John F. Kennedy said, “The hottest places in hell are reserved for those who in times of great moral crises maintain their neutrality.”
  37. Arctic sea ice breaks lowest extent on record
    For what it's worth, this is the area east of Scoresbysund, Greenland, lat 70, on Aug 23.
    Moderator Response: [Sph] Image tag and actual URL repaired.
  38. Matt Ridley - Wired for Lukewarm Catastrophe
    As a reminder, there is nothing magic about 2100AD. Some people seem to want to act like "if we can only keep temperature rise to X by 2100, all is well." When the Earth gets to 2100, I'd guess there will still be much warming in the pipeline from the usual lags.
  39. Matt Ridley - Wired for Lukewarm Catastrophe
    Joel, CO2 emissions and concentrations are already accelerating, and have been for decades. You note the rate of increase is now 2 ppm/yr, in the 1980s it was 1.5 ppm/yr, in the 1960s it was 1 ppm/yr. Unless we do something about it, emissions are expected to continue accelerating (see my link @22). The only way 'lukewarmers' are right is if we take major steps to reduce our emissions.
  40. Matt Ridley - Wired for Lukewarm Catastrophe
    dana @21 - Even to support a linear increase in temperature we need to postulate a exponential increase in CO2. If CO2 continues to increase at 2ppm per year, then we the temperature would increase at a rate much less than 0.14 degrees per decade I get for a linear increase. To get a 3 degree increase, then we have to assume that CO2 would actually double between now and 2100. That works out to 4.4 PPM average for the rest of the century, which means that the rate of increase would have to quadruple by the end of the century. The current rate of increase (2000-2012) is about 45% by the end of the century.
  41. Will the Wet Get Wetter and the Dry Drier?
    It's tricky to get a decent handle on overall effect by eyeballing a global graphic showing annual changes in 5 year trends, but I was played it multiple times looking at a number of regions. Others can try the same and see if they had similar perceptions. Europe & North Africa: worst of everywhere. Mega-droughts. This was the most alarming feature of the whole presentation. Europe still produces very significant amounts of global food production and North Africa is experiencing some of the fastest population growth anywhere on the planet. China: mixed, but experienced bands of both wetter and drier than 20thC average. That will hurt when they have already had some pretty brutal floods and droughts that are going to be exceeded. India: Not quite as bad as Europe, but some major browning in regions of very high population density where access to water and groundwater depletion are already *huge* issues. US: Although the SW saw some dark brown, this was not as extreme as I had expected, since I thought the drying of SW US was one of the major climate concerns. Perhaps I've simply gained that impression by looking at too many US-centric analyses. Mexico is pretty dire. Sub-Saharan & southern Africa: Ouch. Pretty severe drying here. Though my memory is that sub-Saharan African rainfall is one of the bits of climate models where there is least agreement. What did others see?
  42. Why Arctic sea ice shouldn't leave anyone cold
    MA Rodger - thanks, I had intended to include something about the St Roch in the post but forgot. I'm glad you reminded me.
  43. Matt Ridley - Wired for Lukewarm Catastrophe
    Joel @21 - it appears that you are assuming the warming over the next century will continue at a linear rate, which is not realistic, and doesn't tell us anything about climate sensitivity. As we showed here, actual measurements are consistent with a climate sensitivity of around 3°C for 2xCO2.
  44. Matt Ridley - Wired for Lukewarm Catastrophe
    I think the reason that lukewarmers arguments are strong is because it is consistent with the actual measurements. I went though all major temperature indexes and they indicate a warming rate that will increase the temperature by 1.2 to 1.4 degrees centigrade by the year 2100. Here is my graph. Graph of GISS, HADCRU, RSS and UAH indexes
  45. PopesClimateTheory at 05:06 AM on 30 August 2012
    Arctic sea ice breaks lowest extent on record
    It is the land ice that makes the difference!
  46. PopesClimateTheory at 04:55 AM on 30 August 2012
    Arctic sea ice breaks lowest extent on record
    (-Snip-)
    Moderator Response: [DB] Please note (1) that the topic of this thread is Arctic sea ice breaks lowest extent on record, not PopespersonalClimateTheory and (2) this site's Comments Policy.
  47. Why Arctic sea ice shouldn't leave anyone cold
    dana1981 @73 In light of the Christy 1938-43 comments, JMurphy has a very interesting Henry Larsen quote about 1940-42. Larsen had sailed the western Arctic since 1928, including over-wintering up there, so he must rate pretty highly as an expert witness. http://www.skepticalscience.com/StRoch.html
  48. Why Arctic sea ice shouldn't leave anyone cold
    Just briefly regarding our rebuttal posts, one of the primary objectives of SkS is to debunk climate myths by seeing what the peer-reviewed scientific literature has to say about them. That's obviously not the only thing we do, for example we also write posts about new peer-reviewed papers, or as in this post the current state of the climate in general, etc. But it is a big part of SkS (see our myths rebuttals database which is the backbone of the site). So I think it's a little weird to criticize SkS for doing what it has always done, rebutting climate myths.
  49. Will the Wet Get Wetter and the Dry Drier?
    I'm reminded of the way Richard Feynmann dissected the Challenger disaster. Specifically, the way NASA calculated the risk of a disaster. The increase in droughts and floods increases the risk that one day most of the world's agriculture will be wiped out simultaneously by either one or the other. Russia/Australia and Pakistan managed that trick just 2 years ago. In time, the disasters will line up, and that will be that.
  50. Why Arctic sea ice shouldn't leave anyone cold
    We're working on a very detailed analysis of Christy's claims in the Leake article. Look for a blog post on the subject next week.

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