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Comments 69401 to 69450:

  1. Climategate 2.0: Denialists Serve Up Two-Year-Old Turkey
    I'm sure someone must have noted this above, but I'm pleased to notice that my lazy Google search did not bring up any headline about this in the mainstream media. Actually, the only one regarding this "second release" on the first Google page was RealClimate. That's an improvement..
  2. The Debunking Handbook Part 3: The Overkill Backfire Effect
    TatL#17: "creates a "rock-paper-scissors" scenario-- and that presents a wild-goose chase ... In turn, complex relationships evade such thinking, creating a "blind man touching an elephant" scenario," Wow. Three hoary old chestnuts at one go. Well done, sir; you've exemplified the statement in this post: A simple myth is more cognitively attractive than an over-complicated explanation. Some simple explanations, then: a. Science is not 'rock-paper-scissors.' Any time spent reading the complicated literature of climate science will demonstrate that. b. There are no wild geese to chase here. There is a clear objective: understanding what is happening and why, using the best available scientific references. By contrast, the denial-world loves to put up whole flocks of wild geese; they are distractions from the real questions. To answer your specific, see 'It's cosmic rays.' c. The parable of blind men and the elephant doesn't apply. We're not blind; we recognize that observations from multiple disciplines must be reconciled. That provides the familiar 'multiple lines of evidence' so clearly in evidence on this website. I will see your three chestnuts and raise you one: “A frog at the bottom of a well” is a common Chinese idiom, referring to a person with a limited outlook."
  3. Northern hemisphere warming rates: More than you may have heard
    JeeBee @70, as has already been pointed out by DB inline, the NH is warming overall, and indeed is warming with regard to all four seasons. As you have now acknowledged the current effect of the milankovitch cycles would be a continuation of the NH cooling that started approximately 6000 years before present, and continued up until the start of the industrial age. These two fact together contradict your claim in 67 and 68 that "The increasing tilt of earth due to the 41,000 year cycle is responsible for 67-80% of heating we initially thought was due to global warming". Ergo that claim is false. While I agree that climate change is "not currently a major threat" in the very limited sense that if all CO2 emissions where to cease immediately, the danger to humans from CO2 would be limited, and partly balanced by some gains; still it remains the case that continuing business as usual for just 20 more years will take us to a situation in which climate change is a major threat, and continued BAU through to the end of this century would be catastrophic. Because of both social and thermal inertia, that means we need to act now.
  4. Pete Dunkelberg at 03:04 AM on 26 November 2011
    Arctic Sea Ice Hockey Stick: Melt Unprecedented in Last 1,450 years
    Moderator (DB) way back at 11, thanks for the link to Kobashi et al. 2011. When I first heard of that paper I didn't find a pdf. It follows Kobashi et al. 2009: Persistent multi-decadal Greenland temperature fluctuation through the last millennium. Here is a free pdf link to Flanner et al. 2011 mentioned by Tom Curtis. One more hockey stick: Tingley and Huybers' bayesian approach The spatial mean and dispersion of surface temperatures over the last 1200 years: warm intervals are also variable intervals for which I still find only a manuscript, no publication.
    Moderator Response: [DB] Tingley has an identical copy here, but it is to be found nowhere else. Presumably still in review.
  5. Northern hemisphere warming rates: More than you may have heard
    67, JeeBee,
    Ugh!! I hate when people use the word "skeptical" vs "proponent". I wish people would drop those labels. Truth is what we seek, and its much more complex than a simple bipolar "I accept" or "I reject".
    Please leave concern-troll introductions like this out of your posts. Your position (in denial) is clearly evident. Don't pretend to straddle the fence because you think it will cause people to take you more seriously. It has quite the opposite effect. So you come in and trumpet a lot of the same, old, tired misinformation and misunderstandings that hundreds before you have tried. How are you different? How are you doing anything but contributing to the noise? Let me answer the question for you. You're not. If you want to be, you need to drop your preconceptions, recognize that you are speaking from a position of extreme ignorance, stop arrogantly commenting as if you know something no one else does, and instead start reading. This site hosts a wealth of information that you probably couldn't get through in a year (unless you have a whole lot of spare time on your hands). But you do need to understand every bit of it to truly understand what is going on, what the threats are, and who is lying and who is telling the truth. If you are allowing yourself to be fooled by nonsense and misdirection, you only have yourself to blame. Everything you need to learn is here. If you learn and understand it all and still have doubts, then so be it. But by speaking from the position of extreme ignorance and confusion you are in now all you are succeeding in doing is advertising very clearly how ignorant you are and how many misunderstandings you have. Quite honestly, it's embarrassing. I'm sorry to be harsh, but you have to understand how common and tiring your "insights" are. Please, please, please take the time to study and learn first, and develop strong opinions second, rather than the other way around (or just starting with opinions and stopping there).
  6. The Debunking Handbook Part 3: The Overkill Backfire Effect
    TruthAtLast @17: That's precisely why a proper understanding of climate-change requires the complex interaction between solar winds deflecting cosmic rays, and how the Earth's magnetic field can divert sunspot-plasma, but not the higher-speed cosmic radiation from supernovas. ...and sometimes Occam's Razor is required. Flights of fancy and highly speculative fairy-tales with no evidence to support them are completely different from "explanations". I suggest that you read the last two sentences in my comment #13.
  7. Memo to Climategate Hacker: Poor Nations Don't Want Your Kind of Help
    Is there any significance in the reference to FOIA? Wasn't the file named FOIA or something? In the UK the media etc. usually refer to the 'FOI Act', where as American media outlets often refer to 'FOIA'. Do a Google search and you'll see the difference. If I was an American hacker who hadn't thought about it to much, I would probably go straight for FOIA as a name.
  8. Northern hemisphere warming rates: More than you may have heard
    JeeBee#70: "Much scare tactic news comes from winter melt in the Arctic, even though the whole year overall is cooler." Arctic ice melt (which is a summertime thing) is discussed in great detail on a number of threads here - the data speak for themselves, no 'scare tactic news' needed. Please substantiate what 'overall year is cooler.' Claims such as these carry little or no weight in this forum. "At what point would carbon levels have to rise to become a major problem?" They already are. Read. Learn. Ask good questions. Read more. "can humanity mount an effective resolution before its too late?" The biggest hurdles to clear are those posed by the folks who blindly repeat 'no, it's not.'
  9. Northern hemisphere warming rates: More than you may have heard
    67, JeeBee,
    Both sides have valid points.
    No. One "side" has entirely valid points, called "the science," including those few, minor and generally contradicted points that point in different directions. The other "side" has bluster, obfuscation, misdirection and nonsense and tactics. Trying to equate denial with the science, as if the two are on par with each other, is yet another common denial tactic. The two sides do not have valid points. One side has valid points and an understanding of the areas in question, while the other side has nothing.
  10. Northern hemisphere warming rates: More than you may have heard
    Tom Curtis, yes I agree. It is trending towards cooler conditions in the Northern Hemisphere, and warmer conditions in the Southern Hemisphere *overall, but warmer winters in the Northern and cooler winters in the Southern*. Much scare tactic news comes from winter melt in the Arctic, even though the whole year overall is cooler. Sorry for that confusion. Please re-read http://www.skepticalscience.com/LIG5-1110.html. It does show the milankovitch cycle having quite an effect on *observed temperatures*, but not on climate change, again we agree. Yes, climate change is unaffected as far as we know. I assert that Climate change from the data we have gathered *is not currently a major threat to humanity*. However, my questions are these: 1. At what point would carbon levels have to rise to become a major problem? 2. If and when it does become a major problem, can humanity mount an effective resolution before its too late? I think when generating Climate Change *policy*, its important to take those questions into account, not just whether or not climate change is a major issue today due to current observations.
    Response:

    [DB] "It is trending towards cooler conditions"

    Wrt Milankovitch forcings, yes.  But that ignores the very real and sizeable anthropogenic forcings which are unprecedentally warming both hemispheres today.

    "Much scare tactic news comes from winter melt in the Arctic..."

    Please avoid ideological labels like "scare tactics"

    "...even though the whole year overall is cooler."

    Umm, no.  Use the search function again.  The 80s were warmer than the 70s, the 90s were warmer than the 80s, the "Aughts" were warmer than the 90s, etc.  This overall warming trend (not cooling) is well documented.  Or take this portion to the It's cooling thread.

    "Please re-read http://www.skepticalscience.com/LIG5-1110.html"

    If you disagree with the linked post (which you should re-read), take that portion of the discussion there, where it is better-suited.  Long-term forcings, like Milankovitch changes, will cause long-term changes in climate.  Again, well-known.

    "I assert that Climate change from the data we have gathered *is not currently a major threat to humanity*."

    Unsupported and  therefore baseless.  And OT here.  Please take this portion to the It's not bad thread.

    "At what point would carbon levels have to rise to become a major problem?"

    At no point in the past 800,000 years have atmospheric CO2 levels ever exceeded 298.7 ppm.  The last time CO2 levels were this high there was no mankind.  So who says that they are not too high already?

    Click to enlarge

    [Source]

    "If and when it does become a major problem..."

    IBID

    "...can humanity mount an effective resolution before its too late?"

    Who says it's not 40 years too late already (see the Climate Change: The 40 Year Delay Between Cause and Effect thread)?  Even acting now and holding all GHG emissions to zero for the next 40 years, the Earth will continue to warm and the climate will continue to change accordingly.

  11. Arctic Sea Ice Hockey Stick: Melt Unprecedented in Last 1,450 years
    Rob,
    Many climate change "skeptics" obsess over the 'hockey stick', and their discussion inevitably leads back to 1998, when climate scientist Michael Mann first published his paper indicating that current global warming was anomalous in the last 1000 years or so
    In 1998, Mann, Bradley and Hughes published a reconstruction going back 600, not 1000 years. The millennial reconstruction was done in 1999. These two papers often get confused, but usually by skeptics.
  12. Northern hemisphere warming rates: More than you may have heard
    JeeBee @68, the milankovitch cycle to which you appeal is currently trending in the opposite direction, towards cooler conditions in the Northern Hemisphere, and warmer conditions in the Southern Hemisphere. More importantly, it is irrelevant on decadal timescales. As you indicate, obliquity is on a 41,000 year cycle. Therefore over the last fifty years it has only progressed through 0.1% of a cycle, and hence has had negligible effect on change in climate over that period.
  13. Northern hemisphere warming rates: More than you may have heard
    Ok, it was my first post. No caps. >> Global warming is a valid theory from far more than that. Agreed. Just 1 example. >>>Umm, no. The axial tilt of the Earth is unaffected by its temperature. Thats not what I said. Rephrasing: The increasing tilt of earth due to the 41,000 year cycle is responsible for 67-80% of heating we initially thought was due to global warming. http://www.skepticalscience.com/LIG5-1110.html "It takes a lot more carbon to destabilize the planet than we thought." This follows from the previous assertion backed by your own hosted link, that global warming is much *weaker* and therefore more carbon would be required to cause a destabilization event.
  14. Northern hemisphere warming rates: More than you may have heard
    Ugh!! I hate when people use the word "skeptical" vs "proponent". I wish people would drop those labels. Truth is what we seek, and its much more complex than a simple bipolar "I accept" or "I reject". Both sides have valid points. From the graph, it shows both hemispheres have warmed. Therefore, global warming is a valid theory. In addition, there is enough methane on the bottom of the ocean to produce nightmare scenarios of runaway greenhouse effect. However! From data, we see that 67-80% of the warming we assumed was due to global warming was actually increased tilt of the Northern Hemisphere towards the Sun. So that leaves 2-33% for global warming. So what does that mean? It takes a lot more carbon to destabilize the planet than we thought. Thats a good thing, it gives us more time. But that doesn't mean we are not capable of destabilizing it! Just because we have much more leeway than we thought, there is absolutely no need to test the limits of what our planet can handle!!
    Response:

    [DB] "From the graph, it shows both hemispheres have warmed.  Therefore, global warming is a valid theory."

    Global warming is a valid theory from far more than that.

    "From data, we see that 67-80% of the warming we assumed was due to global warming was actually increased tilt of the Northern Hemisphere towards the Sun."

    Umm, no.  The axial tilt of the Earth is unaffected by its temperature.

    "It takes a lot more carbon to destabilize the planet than we thought."

    This is an unsupported assertion.  Please provide a supportative link.

    Please note that the use of All-Caps (which I have reverted back to caps & lower case for you) is a Comments Policy violation.  Please take the time to familiarize yourself with it.  Thanks!

  15. Memo to Climategate Hacker: Poor Nations Don't Want Your Kind of Help
    Whoever is really willing to help the poor I'm sure would not miss any chance. They need food AND water AND health care AND education AND ... [long list here]. A liveable environment is one of the prerequisites. The problem, then, is not who wants to help the poors and who does not, it's the perception that climate change is not a threat, which may turn out to be a fatal mistake. Providing food, water or whatever without helping them building their future will result in their being poor forever, surely not a desirable outcome, not to me at least.
  16. Arctic Sea Ice Hockey Stick: Melt Unprecedented in Last 1,450 years
    Rob Painting, Skept.fr: As discussed in an earlier SkS post, the MWP seems to have been a re-organization of the global climate. Despite the localized warming aroung Greenland, the global mean background state was much cooler than today. Also consider that the map is relative to 1961-90 and that the Greenland area was relatively cold during this period, even compared to earlier in the 20th Century. That said, I'm with Skept.fr on being skeptical of these findings. The MWP doesn't just show smaller change than today, but change in the opposite direction to what we would expect. And the previous lowest minimum occurring during the Little Ice Age? It's counter-intuitive at least. Could it be that cooling in Europe was due to some prolonged blocking pattern caused by, or resulting in, a warmer Arctic? I guess I'll have to check out the paper.. hope my Nature subscription hasn't expired yet.
  17. Memo to Climategate Hacker: Poor Nations Don't Want Your Kind of Help
    Most likely the thief does believe what he says about the poor countries but it is not his sole or even main motivation. If the time zone information is correct then he probably did it from ideological motives.
  18. Incredible time-lapse video of Earth from space
    @chriskoz #3, You're seeing 'airglow'. http://astrobob.areavoices.com/2009/02/25/is-there-true-darkness/
  19. Memo to Climategate Hacker: Poor Nations Don't Want Your Kind of Help
    My view is that the readme is a smockscreen to try to hide the identity of the hacker. He uploads the emails to a Russian server. He artificially sets the date on the files to hide his time zone in the newest batch of emails. He creates a readme file to suggest his aim is to protect the poor. Yet first time round he made a few mistakes. The most serious was leaving time zone information on the zipped files, where was his time zone? -5 GMT, most likely Eastern Canada or USA. He is not really interested in protecting the poor at all.
  20. The Debunking Handbook Part 5: Filling the gap with an alternative explanation
    I'm finding this handbook very useful indeed. Nice work!
  21. Arctic Sea Ice Hockey Stick: Melt Unprecedented in Last 1,450 years
    Arkadiusz at #48 is a good example of how the reading of scientific papers by people untrained in that specific topic may be tricky. In the conclusions of Kobashi et al. quoted by Arkadiusz, the authors highlight the possible reasons of the discrepancies between Central Greenland and the Arctic as a whole. This should sound as a ringing alarm bell to those who'd like to use their reconstructions as indications of a more general trend. Indeed, the authors are clearly trying to put central Greenland temperatures in the context of the Arctic as a whole to improve the understanding of the former. As already noted by Tom @50, Arkadiusz himself highlights the reason why his quote is irrelevant to the topic at hand, which makes me wonder why he extensively quoted it.
  22. Memo to Climategate Hacker: Poor Nations Don't Want Your Kind of Help
    That is absolutely correct Marcus. Distributed solar energy is economically a better option for many Africans: http://environmentalresearchweb.org/cws/article/news/47187
  23. Arctic Sea Ice Hockey Stick: Melt Unprecedented in Last 1,450 years
    With great irony, I have just finished a post that establishes yet another of Arkuiusz' frequent misquotations to find him claiming that he is falsely accused of cherry picking. Of course, deliberate misquotation is just another form of cherry picking (and a particularly deceitful form of it). So, having given us yet another example of cherry picking, he then denies that he practices that vise in the very next post. As I said, very ironic. More relevantly, Arkadiusz' 48 is in fact irrelevant to this topic, and he has kindly highlighted for us the reason why it is irrelevant.
  24. Arctic Sea Ice Hockey Stick: Melt Unprecedented in Last 1,450 years
    Arkadiuz Semczyszak @47, quotes from Chung and Räisänen 2011. However the full paragraph from which he quotes read:
    "If the models simulate climate feedbacks correctly, the indication is that models have significantly incorrect climate forcing. Since GHG forcing is well established, the problem is likely in how the models treat aerosol effects. In this scenario, the real aerosol forcing might be significantly positive in the Arctic and significantly negative outside of the Arctic, while the models miss this feature entirely."
    Clearly the conditional statement which Arkadiusz omitted is crucial to the meaning of the authors. In fact they are presenting one of three possibilities which their study is unable to distinguish between - the other two being that tropical feedbacks are overestimated, and that arctic feedbacks are underestimated. By omitting the conditional, Arkadiusz has quoted a conditional as a firm conclusion of the study. In fact, a recent study, Flanner et al, 2011, already finds evidence that the third option (which Arkudiusz misquotation conceals) of greater than predicted feedbacks is what is driving the unexpectedly rapid arctic melt:
    "Hemisphere forcing at −4.6 to −2.2 W m−2, with a peak in May of −9.0±2.7 W m−2. We find that cyrospheric cooling declined by 0.45 W m−2 from 1979 to 2008, with nearly equal contributions from changes in land snow cover and sea ice. On the basis of these observations, we conclude that the albedo feedback from the Northern Hemisphere cryosphere falls between 0.3 and 1.1 W m−2 K−1, substantially larger than comparable estimates obtained from 18 climate models."
    (My emphasis, see here for discussion on SkS) Taken together with Chung and Räisänen 2011, this suggests that models tend to underestimate climate sensitivity as Chung and Räisänen indicate.
  25. Arkadiusz Semczyszak at 19:17 PM on 25 November 2011
    Arctic Sea Ice Hockey Stick: Melt Unprecedented in Last 1,450 years
    (-Snip-) None of the cited work does not settle here finally - objectively - last question - in this lengthy (sorry) quotation. My “alleged” - a typical “trick for skeptics” - "cherry picking" - use absolutely all the authors cited papers. Their subjective views on AGW have too much influence on the results - conclusions.
    Response:

    [DB] Tom again deconstructs your continued cherry-picking in comment 50 and its irrelevance below.

    Extensive block-quoting (from the Kobashi paper discussed earlier in this thread) without appropriate context snipped.

  26. actually thoughtful at 18:55 PM on 25 November 2011
    The Debunking Handbook Part 4: The Worldview Backfire Effect
    This is, I think, the key issue when dealing with so-called skeptics (that their world view prevents reality from getting within shouting distance of their opinions) WV Quine wrote about this in his book Web of Belief. Very interesting stuff. I have found, when posting on message boards, that if you make somewhat of a connection with a poster before "educating" them (my friend calls this hitting them on the head with a dead fish - making the sound "whop" - thus whopping them) - you don't necessarily get to agreement, but you might get to an agreement to think about it. And that connection can be relatively tenuous - something that gets the other person thinking about you as a human being - not a 'bot of opposition. I once achieved the effect by simply writing "That is the most rational post I've ever seen you make" (not calling him rational, just more rational than usual - which COULD have been taken as an insult). We ended up having a decent discussion. The most key point is that you can't change the 20% or so that are committed to being ignorant. You can change their behavior (ie trampolines and getting the gubment off our back) - but they will die believing that climate change is a HOAX.
  27. actually thoughtful at 18:45 PM on 25 November 2011
    The Debunking Handbook Part 4: The Worldview Backfire Effect
    What is a concern troll?
    Moderator Response: [DB] See here.
  28. Arkadiusz Semczyszak at 18:38 PM on 25 November 2011
    Arctic Sea Ice Hockey Stick: Melt Unprecedented in Last 1,450 years
    „... language barrier ...” ... of course yes - but only the “language of statistics”. The standard deviation is huge for the whole range of variation described by proxy - to the nineteenth century. For this we must add: „...extensive uncertainties remain, especially before the sixteenth century ...” For those who are “convinced” of the compatibility of temperature changes in the Arctic with the estimated GHGs forcing - in comparison - another forcing: Chung and Räisänen 2011 : Implications: “Since GHG forcing is well established, the problem is likely in how the models treat aerosol effects. In this scenario, the real aerosol forcing might be significantly positive in the Arctic and significantly negative outside of the Arctic, while the models miss this feature entirely.”
    Response:

    [DB] And with this you are back to your long-established practice of cherry-picking quotes, as Tom notes below in comment 49.  The practice for which you have been cautioned and warned against ad nauseum.  And which you have ackowleged with the intent to do better.  Yet here we are.

    Language barriers are no longer an excuse, as this behavior is demonstrably willful.  No more.

  29. Arctic Sea Ice Hockey Stick: Melt Unprecedented in Last 1,450 years
    Mandas and others, The silly story about Erik the Red came from Hubert Lamb, first director of CRU and the man behind the MWP concept. That Lamb used it shows the primitive state of temperature reconstructions just a generation ago.
    Response:

    [DB] "The silly story about Erik the Red came from Hubert Lamb"

    Then you will certainly have no problem furnishing a link to support your Hubert Lamb claim.  If he did indeed use it, then you will have to furnish also the context in which he used it and then demonstrate why that is relevant to this thread.  Else you are being silly and off-topic and therefore this comment will be deleted.

    "That Lamb used it shows the primitive state of temperature reconstructions just a generation ago."

    This is certainly an unsupported, subjective and indeed off-topic comment.  Other comments exist here on models and their qualitative states.  The Search function will reveal many.  Continue this line of reasoning there, not here where it is off-topic.

  30. Arctic Sea Ice Hockey Stick: Melt Unprecedented in Last 1,450 years
    So far as I know, speculation about their level of subsistence prior to the eventual collapse is no more than speculation, and they were trading with Europe for a considerable portion of that time. They were there for a long time for the walrus ivory, not just to scratch out the barest existence imaginable, and lived in climate conditions comparable to some of those in parts of Iceland or Norway. But indeed that's for another day, we quite agree that it is utterly irrelevant for the topic and for AGW in general, despite skeptics suggesting otherwise!
  31. Arctic Sea Ice Hockey Stick: Melt Unprecedented in Last 1,450 years
    skywatcher @43 I concede to your point about surviving for about four centuries, but am not so sure I'd agree that they did "very well". We don't know how long they were in decline and thus we don't know how long they were hovering on or just below subsistance levels. True, the encroachment of the Inuit Thule culture was a major factor and one wonders whether competition for resources escalated to outright warfare. I expect the collapse of bow head whale resources was a result of increased competition for the same resource pool but admit that is just speculation. In any case, rather than lead this thread off topic, I see from your list of possible causes for the failure of the settlements we agree about what is relevant to AGW science. The failure of Norse Greenland cannot simply be sheeted home to MWP or LIA.
  32. World Energy Outlook 2011: “The door to 2°C is closing”
    skept.fr @42, I apologize for this late and limited response. I am very short of time at the moment, and as a result my commentary on more difficult subjects (including this one) has dropped of. Clearly I was in error regarding total energy consumption. That being the case, I would point out that if you are correct that the value of energy is not properly captured by its cost as a percentage of GDP, then expenditure on energy conversion will rise as a shortfall in usable energy develops, meaning conversion to RE will be faster than that suggested by SSREN scenarios. There can be no question that we could make the conversion to a zero carbon economy if we where determined to do so. Available solar energy is 11,000 times our current usage. Available wind energy is 78 times our usage. Available wave energy is 4 times our usage. (Figures from Richard Alley, Earth: The operators manual") Nor is there any question that we currently have all the technical expertise required. Even issues of intermittency are, as engineering problems, easily solved. What is not clear is whether they can be solved with low economic, social and ecological cost. In short, the issue of moving to a carbon free economy by 2050 is not can we, but will we pay the costs of doing so, where the cost is a small percentage of GDP. With regard to food, the IPCC AR4 indicates increases in temperature above 3 degrees C will reduce crop yields world wide. That is in addition to the loss of crop land due to changes in precipitation patterns. There will be similar losses in fishery production as warming water results in arctic (high oxygen) biomes being replaced by temperate and tropical biomes. On top of that there is a significant probability of the destruction of major barrier reefs, and in the long term the generation of anoxic oceans due to ocean acidification coupled with warming seas. It is the later possibility which represents the complete collapse of global fisheries (if they do not collapse before then due to the earlier, smaller effects of global warming coupled with over-fishing). So, from my point of view, the dilemma we face is the choice between a possible slowing of global growth in energy usage vs a probable decline in global food production. Faced with a population growing from 7 to 9 billion, it is the later which is the greater cause for concern. Unfortunately, and again I apologize for this, I will not have the time to argue these points in detail in coming months.
  33. Arctic Sea Ice Hockey Stick: Melt Unprecedented in Last 1,450 years
    Marcus and Stevo #36-38, it's worth noting that the settlers on Greenland did very well for 400 years, and successfully adapted to climate change during their time there (onset of LIA). Their diet went from mostly terrestrial to 80% marine (Arneborg et al, you can tell from the isotopic composition of their bones) as they changed their diet to be mostly seals. So it wasn't a failure of their agriculture that killed them. It's fair to say it wasn't the cold alone that killed 'em (Diamond is out of date), could also be conflict with the Inuit, world economics and politics, disease, or some unholy mix of the lot. But failure to adapt is not something you can easily accuse them of, given what is now known from the archaeology.
  34. Arctic Sea Ice Hockey Stick: Melt Unprecedented in Last 1,450 years
    Albatross @23 If there was a climate cycle, there is no reason why we should be near the top of the climate cycle and about to go into a cooling phase any year. It could be a 4500 year climate cycle that we are 300 years away from peaking in. But it seems a curious element of 'skeptic' psychology that no matter what cycle is proposed we are always nearly at the peak of the cycle and it is always predicted that temperatures will cool any year, or have been cooling since 1998/2002/etc.
  35. Climate sensitivity is low
    249, Eric, Q1: My opinion only, but no, I don't think a return to 285 is necessary, just desirable (but impossible). I do think a return to 350 is required, but also impossible at the current rate of action (meaning that by the time we start, we'll be lucky to hold it to 500 at this point, and as I described, I think getting it down once its up will be almost impossible). Q2: How do you propose that the carbon get into the deep ocean? There are natural processes that work on huge, huge ("global") scales, but not nearly so quickly as to naturally drawn down both atmospheric and ocean CO2 levels to a reasonable degree (although I could be wrong on this... this is where an ocean expert like Doug Mackie should step in. Perhaps he knows better. But otherwise, how does someone suck all of that carbon out of the air and oceans and put it in a form that will sink to the bottom and stay there? It is interesting to note two things. The first is that the 300+ gigatonnes of carbon that man has burned in fossil fuels so far (and we're still not done) took nature hundreds of millions of years to sequester underground. It took a mere 100 years to release it, but there is no reasonable way to match nature's feat and put it back. It can go into the atmosphere, ocean or biomass, but not very easily back into the ground. The second point is that I recently did a back of the envelope calculation, trying to figure out how much land would be needed to plant giant sequoia redwoods that could suck up the carbon and turn it into biomatter (trees). The answer, with some very optimistic fudging, was that 75% of the arable and agricultural land on earth needed to be covered with redwoods in order to drawn atmospheric CO2 back down to 285 ppm in the course of 100 years from today, assuming we planted those trees right now and also instantly stopped burning more fossil fuels. This of course presumes that all of humanity moves to deserts and other places of the earth so that we can exclusively grow food crops on the remaining agricultural/arable land. Of course, since that represents only 25% of the total, we must also assume that food production will drop by 75%. This implies that the population of the earth (currently 7 billion) must also drop as a consequence -- so that "solution" implies: 1) Plant sequoias immediately on 75% of the arable land on earth (completely ignoring the fact that sequoias will not grow just anywhere, and in fact could only grow in very specific environments) 2) Move the entire human population off of such land 3) 5 billion people must die (because there won't be enough land to produce enough food to feed 7 billion, but instead only 2 billion).
  36. Arctic Sea Ice Hockey Stick: Melt Unprecedented in Last 1,450 years
    skept.fr @39 and mandas @40 Agreed. Denialist arguments about the MWP consistantly fail upon examination and are greatly overstated in both extent and consequence.
  37. World Energy Outlook 2011: “The door to 2°C is closing”
    skept.fr @65 CO2 emissions from the reduction of steel are a very low percentage of total emissions. They can safely be left until much further into the energy transition. In the long term, coal can be replaced by charcoal for reduction, thus rendering the process carbon neutral. Direct heating is an important use of coal (and oil and gas). However, in all instances it can be replaced by heating using electricity, and in some cases could be replaced by the use of solar furnaces. Further, energy consumption for direct heating in industrial processes is included in estimates of total energy use. Therefore this is not an additional requirement on top of those already being discussed.
  38. Arctic Sea Ice Hockey Stick: Melt Unprecedented in Last 1,450 years
    Well, I must admit I had heard every denier argument, but Lars @ #19 has produced the best one ever!! So the cousin of Erik the Red swam over two miles through Greenland waters and then swam back, carrying a full grown sheep. And that's your argument against climate change and for the MWP?? What is this, Poe's Law? If you believe that either happened or is even possible, I have a nice bridge to sell you.
  39. World Energy Outlook 2011: “The door to 2°C is closing”
    Document of interest in the debate: the IEA roadmap for CCS (2009) . About the economic cost of mitigation: "IEA analysis suggests that without CCS, overall costs to reduce emissions to 2005 levels by 2050 increase by 70%." But Joe Romm documents (#61) point to the opposite. Hard to decide. #63 scaddenp : yes, coal as a fuel and reducing agent (coke) in metallurgy is often forgotten. It is also used (for heat) in cement, glass, ceramic or paper industry, so these intensive processes must be included in the RE package if substituting coal rather than capturing CO2 from its combustion is the only option.
  40. Newcomers, Start Here
    Sphaerica @154, you are correct that my post was intended as a response to your 139 rather than your 143. I am sorry for the confusion, and would appreciate a moderator amending the original post to avoid confusion for any newcomers reading these posts. It is also true that I detailed what I consider the real reasons for Mars' weak greenhouse rather than explicitly rebutting the reasons you gave. I will correct that here. Before turning to that, I note that you raise another point as explanation of Mars low greenhouse effect, ie, the absence of H20. I of course agree that a mass of water vapour in the martian atmosphere equal to the mass of water vapour in Earth's atmosphere would substantially raise temperatures on Mars. However, the factors that weaken the greenhouse effect of CO2 on Mars (as given in 145 would also weaken the greenhouse effect of water vapour. What is more, my calculation that if the CO2 on Mars has as strong a greenhouse effect as it does on Earth, it would warm the planet by approximately twice what it does is not effected by the absence of water vapour. Hence, the absence of water vapour is not the reason for the unusually weak greenhouse effect on Mars. Turning to your explicit explanations from 139, you first state that on Mars there are few gases for CO2 molecules to transfer energy to by collision "...so radiation dominates, and energy transfer up and out is quick" It is certainly plausible that energy transfer by radiation is quicker on Mars than in Earth's troposphere. For newcomers, this refers not to the transit at IR photons (which is at the speed of light), but to the average time taken between absorption and emission of photons, divided by the average distance traveled by a photons between emission and absorption. Also note that this always refers to transfer of energy at a particular wavelength. Clearly energy transferred outside the wavelength of the absorption band of a greenhouse gas will leave the atmosphere at the speed of light. Plausible though that is, it does not follow that radiation dominates energy transfer within the atmosphere of Mars. Indeed, it is known that Mars has a distinct troposphere,ie, the region of the atmosphere in which convection dominates radiation as the means of energy transfer. The martian troposphere is about 45 km in depth. Further, it is known that the troposphere on Mars is dominated by convection because the lapse rate in the troposphere is that calculated for the adiabatic lapse rate, ie, the rate of change of temperature that results from convection in a dry atmosphere. In your post 139, you then go on to say:
    "In the Earth's atmosphere a very, very important piece of the puzzle is that closer to the surface, where the air is denser, CO2 absorbs IR, but before (usually) it is able to re-emit that energy, a collision with O2 or N2 transfers that energy to those molecules, which do then not as easily or as readily emit energy in the infrared. The end result is that surface radiation heats the CO2, and the CO2 heats the surrounding atmosphere. As one gets higher and higher in altitude the atmosphere becomes less and less dense, and the balance shifts, so that eventually radiation becomes the key factor, and CO2 acts to cool rather than to warm (i.e. collisions between O2/N2 and CO2 transfer energy from the O2/N2 to the CO2, which is then emitted as IR and potentially lost to space)."
    Unfortunately this only presents part of the picture, and draws the wrong conclusions as a result. The most important thing missing is that CO2 gains energy from collisions as well. How frequently that happens depends entirely on the temperature of the gas. The higher the temperature, the more frequently CO2 will collide with a molecule (of whatever variety) that has higher kinetic energy, and will receive enough energy to emit a photon as a result. Note that if the gas is cool, other molecules will draw of energy from a given CO2 molecule more frequently than they transfer energy to that molecule, and so absorbed energy will tend to be dispersed within the gas, thus warming it. This will be the case even if the gas is 100% CO2. Conversely, if the gas is hot, CO2 molecules will absorb energy from collisions more frequently and hence emit photons at a higher rate, thus cooling the gas. The average rate of emissions of the CO2 therefore depends entirely on the temperature of the gas, and is not effected by its composition (provided it contains some CO2). Composition does effect the rate at which the gas approaches equilibrium. Additional nitrogen or oxygen molecules will result in the gas taking longer to warm by the absorption of IR radiation. But it will not directly effect the rate of emission or absorption. (It will indirectly effect it by either increasing pressure if we do not increase the volume of the gas, thus resulting in pressure broadening, or by decreasing the optical thickness of a given depth of the gas if we increase the volume, but that is a separate issue.) Note that because the rate of emission depends entirely on temperature, whether CO2 cools or warms depends entirely on the temperature of the gas relative to the amount of radiation being absorbed. If on average a CO2 molecule receives more energy from collisions than from radiation, the net effect is to cool the gas. If the CO2 receives more energy from radiation than from collisions it warms the gas. In the stratosphere, CO2 cools the gas not because of altitude, but because the gas is heated by ozone absorbing ultraviolet radiation to a temperature far above that which would establish an equilibrium between absorption and emission for CO2 in the IR spectrum. Finally, and unfortunately, I also cannot find hard numbers on these points. I have long found that scientists have a distressing habit of using their scarce resources to conduct experiments that advance their knowledge rather than ones which would aid exposition of the basics of the theory. The hard numbers we are after here are, of course of trivial interest to working climatologists. (Perhaps we can persuade Science of Doom to look at the issue when s/he returns from their hiatus.) In the meantime, these illustrations will be of interest. The first shows the temperature profiles of Venus, Earth and Mars, along with an indication of their temperature without the greenhouse effect. The second shows the absorption spectra of Venus, Earth and Mars. You will notice the pressure broadening of the central CO2 absorption band, very obvious when comparing Mars and Venus, but also noticable in comparisons to Earth:
  41. Arctic Sea Ice Hockey Stick: Melt Unprecedented in Last 1,450 years
    Interestingly, in the Kinnard 2011 paper, there is nothing but a little uwpard trend of sea-ice extent during the usual core 'MWP' 900-1200. And the sharpest decline before the 1950-2010 condition occured... during the LIA. From the authors : 'The pronounced decrease in ice cover observed in both our terrestrial and oceanic proxy-based reconstructions between the late fifteenth and early seventeenth centuries occurred during the widespread cooling period known as the Little Ice Age (about ad 1450–1850 (ref. 18)). Reconstructed Arctic SATs show episodes of warming during this period (Fig. 3f), but according to our results the decrease in Arctic sea ice extent during the Little Ice Age was more pronounced than during the earlier Medieval Warm Optimum.'
  42. World Energy Outlook 2011: “The door to 2°C is closing”
    My guess is that CCS, if it is ever used on a large scale at all, will likely be deployed as remediation (rather than mitigation) in the latter half of this century, to correct what will almost certainly be an overshoot in any safe or acceptable level of CO2 concentration. See for example the two slides on page 11 of this presentation. The audio for this talk (by Myles Allen) can be accessed here. This is a talk worth watching in its own right, anyway. Given the massive problem we face in decarbonizing our energy supply (and eventually, probably, the atmosphere itself) I don't see why we should write off any potential contribution to a solution at this point. I know, after having paid a fortune to the oil companies for having them extract the carbon from the earth, to have to pay them again for putting it back, is a bitter pill to swallow.
  43. Arctic Sea Ice Hockey Stick: Melt Unprecedented in Last 1,450 years
    Clarification to my last posting. The effect of climate change on the Norse Greenland colony may have been that expanding sea-ice made communication between Greenland and Scandinavia more difficult. However this has little if any bearing on the fact that the colony failed due using inappropriate agricultural practices for Greenland conditions.
  44. Arctic Sea Ice Hockey Stick: Melt Unprecedented in Last 1,450 years
    As someone whose background is both historiography and history I'm surprised that Viking colonisation of Greenland is considerred to in any way significant to climate history. Eric the Red chose the name "Greenland" for marketing purposes in order to attract settlers rather than as an accurate description of the place he had spent three years exploring. The failure of the Viking settlement on Iceland is held as an example of how failure to adapt agricultural practices to suit local conditions will doom colonists to failure. Similar examples of such failure to plan a colony and fail to adapt to local conditions can be found in British and French colonial failures in continental North America. Again, climate change is not a factor in these failures. From an historian's perspective the failure of Viking settlement in Greenland is an entirely seperate subjuect to climate history.
  45. Memo to Climategate Hacker: Poor Nations Don't Want Your Kind of Help
    The fact is that most developing Countries will benefit far more from relatively cheap (in both the medium & long term) distributed energy generation projects(like bio-gas derived from various waste streams, coupled with localized solar, wind & micro-hydro projects) than they would from large, centralized power generation projects which will have a large land-use footprint, create enormous amounts of toxic waste and/or cost a lot in ongoing non-renewable fuel. I know which approach I'd pick if I was seeking to alleviate poverty....just as I know which approach I'd use if I was seeking to line the pockets of the big resource corporations (like Rio Tinto & BHP).
  46. World Energy Outlook 2011: “The door to 2°C is closing”
    It would depend on where you are for getting enough RE at that price. Also, you arent going to find an alternative to coal for steel-making any time soon.
  47. Arctic Sea Ice Hockey Stick: Melt Unprecedented in Last 1,450 years
    Actually, on reading my copy of Jared Diamond's book "collapse", there is very strong evidence to suggest that the Greenland Colony was always close to collapse, with supplies from Norway being frequently required to keep it going. Of course, once the LIA hit, said supplies could no longer arrive as frequently-which caused the colony to finally collapse.
  48. Memo to Climategate Hacker: Poor Nations Don't Want Your Kind of Help
    You can read the full ALBA-LDC statement for Durban here . The original figures for 10,5 trillion $ additional investment in 450 scenario compared to Reference Scenario in WEO 2009 report are here and here .
  49. Arctic Sea Ice Hockey Stick: Melt Unprecedented in Last 1,450 years
    Hem, not better (!), read for the last sentence : "This is the birth context of the 'Medieval Warm Period' context concept, in the 1960s".
  50. Climategate 2.0: Denialists Serve Up Two-Year-Old Turkey
    Blessthefall, You really do need to consult the comment policy as Daniel has advised you to do. Lots of people here offer differing opinions or "dissenting" views-- look at this thread, "The greenhouse effect and the 2nd law of thermodynamics", it now stands at 1000 comments, with many, many of those posts made by what you would call "dissenters", see posts by damorbel, RW1, and FredStaples. That is just one thread here at SkS. Like them, you are welcome to post, but there are house rules, and each one of your deleted posts has violated the house rules in one way or the other-- claims of corruption, complaints about moderation etc. If you have a point to make, consult the comments policy and check the vitriol, rhetoric etc at the door, and always back up your assertions with facts when possible.

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