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Comments 71801 to 71850:

  1. Hyperactive Hydrologist at 21:53 PM on 24 October 2011
    The BEST Kind of Skepticism
    Dale, Can I suggest you back up claims with references from the scientific literature. This adds scientific evidence to your argument and differentiates a sceptic from a denier. I would be interested if you have a source for this? "The drop in UV was attributed to cause a cooling in the stratosphere which induced stronger chlorine reaction with ozone, thus depleting it more and causing the arctic ozone hole." As DB has referenced an article that claims otherwise this adds doubt to your credibility.
  2. The BEST Kind of Skepticism
    @ Dale. (-Snip-) First of all, if the entire decade of 2000-2010 was warmer than the entire 1990's & 1980's, then this means that warming DIDN'T STOP-a simple fact that even a simpleton should be able to grasp. Using an outlying year like 1998 is a fairly typical tactic of the (-snip-), but one which doesn't change the fact that there was an additional 0.1 to 0.17 degrees of warming between 2000 & 2010-depending on which dataset you rely on. Second of all, if the stratospheric cooling were the result of falling UV radiation from the sun, then we should have seen a correlated fall in tropospheric temperatures as well-yet instead we see rising tropospheric temperatures at the same time as stratospheric temperatures are falling-very unusual & not consistent with any *natural* cause of climate change we know of. Also, contrary to your claims, the Tropospheric Hot Spot is meant to exist even in a non-warming atmosphere. It is *not* a fingerprint of GHG warming. Nor, indeed, has it been proven to not exist, its just been difficult to confirm its existence using existing technology. Thirdly, there is a strong correlation between Total Solar Irradiance & Sunspots-where both datasets exist. However, as TSI data has only been recorded since 1978, its difficult to use data we don't have. Also, climatologists have shown a very strong correlation between sunspot numbers & previous climate change. (-snip-). Fourthly, Muller *has* sucker punched Watts very nicely. Watts' meme for almost the last decade is that the planet hasn't been warming, but that its simply down to Urban Heat Island effect-Muller is the latest in a long line of researchers who've debunked this meme, but still Watts & his (-snip-) band of camp followers continue to cling to it-which I consider to the height of arrogance & rudeness.
    Response:

    [DB] Inflammatory snipped.

  3. The BEST Kind of Skepticism
    Oh and Marcus, just on the UV thing. Not sure if you saw it but a couple weeks ago the arctic ozone hole was talked about around the traps. The drop in UV was attributed to cause a cooling in the stratosphere which induced stronger chlorine reaction with ozone, thus depleting it more and causing the arctic ozone hole.
    Response:

    [DB] You are aware, aren't you, that the enhanced GHE is responsible for said stratospheric cooling that is responsible for the increased Arctic ozone hole?  More confirmation of AGW.  Perhaps more reading of the science and less of the dissembling sites you mention is recommended.

  4. The BEST Kind of Skepticism
    les @53 Muller hasn't "sucker-punched" anyone. He's confirmed what everyone knows and acknowledges: that the Earth has warmed. cRR @54 I have no problem with the GHG's causes warming argument. They do. Just because I don't believe every argument from the AGW side doesn't mean I don't believe in how the greenhouse effect works. As for heat, the first graph implies that ocean heat content has risen steadily. It hasn't. CBDunkerson @55 The SkS article does not say "some amount". It states that "human activities are causing climate change". There's no mention of natural cycles/influences at all. Basically, the SkS comment is misleading. Marcus @56 Please read what I said above. Just because the decade was the hottest, does not imply the temperature kept rising. Yes, 9 of the top 10 hottest years on record were from that decade, but only once was the 1998 record broken: 2005. 2010 was hotter than 1998, but didn't break the record set in 2005. BTW, cooling of the stratosphere can also happen due to reduced inbound UV. Which has been dropping for quite a while. In fact, GHG warming should also develop a tropical hotspot, which doesn't exist. Yet UV reduction would result in cooler upper stratosphere and no tropical hotspot. Sunspot trends? Oh come on. There's many natural cycles, and sunspot trends is just one of them. TSI is a better trend to follow than sunspots anyways. Arctic ice can also (and has been) melt from below up. This could possibly indicate warmer waters out of the thermohaline. But since the world got warmer, the ice is gunna melt mate.
    Response:

    [DB] "Yet UV reduction would result in cooler upper stratosphere and no tropical hotspot."

    With the introduction of this well-known denialist meme Dale stands revealed.  The "hot spot" mentioned is known to be a signal of any warming, not AGW-specific warming.  Note the Gish Gallop introduced to shift goalposts.

    Can we all now return to the subject of this thread, The BEST Kind of Skepticism?

  5. Berkeley Earth Surface Temperature Study: “The effect of urban heating on the global trends is nearly negligible”
    +1 for CBDunkerson's observation at #9.
  6. Arctic Ice Volume is diminishing even more rapidly than Area
    "The 2011 minimum has reached the lowest volume for 8000yrs" Georg Heygster, head of the polar research group at the University of Bremen,... (Overpeck 2005) "There is no evidence that the Arctic has been seasonly ice free for the past 800,000yrs". * seasonly ... not just one day but full season.
  7. The BEST Kind of Skepticism
    @ Dale, another thing to consider re post-2000 warming is that the rate of Arctic Ice decline has been much higher than predicted in the models, which suggests that at least some of the warming which should have gone into the atmosphere, is instead being lost to melting ice. Not a good thing for us btw.
  8. The BEST Kind of Skepticism
    Another thing, Dale. If human activity is not responsible for the warming of the last 60 years, then how do you explain that, in spite of a significant decline in the Sunspot trends for 1950-2010, we're seeing a warming trend of greater than +0.12 degrees per decade (with a warming trend of +0.16 degrees per decade for 1980-2010), yet the period of 1890-1950, the warming rate was less than 0.1 degrees per decade-in spite of a significant increase in sunspot numbers during that time period?
  9. The BEST Kind of Skepticism
    "If the question is the later, then technically it hasn't according to HadCRUT, CRUTEM, NCDC, and the RSS, UAH satellite feeds since 2000 (GISS shows a slight warming)." Oh, that old chestnut, it really does make me laugh no matter how often I hear such a patently false comment. Even if you ignore the lack of statistical significance, the reality is that-for the period of 2000-2010-RSS shows a warming trend of +0.01 degrees per year, UAH shows a warming trend of +0.017 & GISS shows a warming trend of +0.014 degrees per year (as compared to a warming trend of +0.016 degrees per year for 1980-2010). Fact is that it wasn't just 2010 that was the hottest year on record-9 of the 10 hottest years on record have been since 2000-something which should not have occurred if the warming had stopped or if cooling had set in. Yet given the fact that we've had a significant increase in sulfate aerosols & a significant decrease in total solar irradiance, we should have started to see some kind of cooling by now-yet clearly we're not-not even a significant slow-down in the rate of warming. As to your claims regarding the AMO, you are aware that Ocean Oscillations can't create heat-that they merely shift it from place to place, or between the ocean & the atmosphere. Any changes in the AMO (or ENSO) must be therefore due to an external forcing-either solar radiance (unlikely given the 30 year downward trend) or increased warming via greenhouse gases. Also, a significant fingerprint for GHG-as opposed to natural-warming is the ongoing cooling of the stratosphere. Now, you got any more Denialist Propaganda to try & spread at this site, Dale?
  10. The BEST Kind of Skepticism
    Dale, it is unequivocal that human activities are causing some amount of climate change. I can't think of a single 'skeptic' scientist who disputes that. Not Muller, not Lindzen, not Pielke, not Spencer... heck, not even Singer. You've moved the goal posts again. Before you claimed that CO2 is promoted as the sole cause. Now, as 'proof' of that, you present evidence that SkS says human activities (including, but not limited to CO2) are >a< cause. As to Muller, see my first comment on this thread. He (like Curry) has a history of making unsubstantiated statements at odds with established reality from a place of ignorance. Again, at least this time he had the sense to include a 'may be' disclaimer. If he looks into this, as he eventually did with the temperature record, he will find that it is equally false... as many other researchers have already established, just as they had for his false claims on the temperature record before the BEST project even began. If, as les suggests, Muller is 'setting up' the skeptics I'd be both appalled and impressed. Impressed by his willingness to sacrifice his own credibility, but appalled by a strategy of 'revealing the truth through deception'.
  11. The BEST Kind of Skepticism
    Dale #52, the graphs do not show the contradiction you want to read in it. Apparently the one is taking more of a running mean than the other, big deal. Heat increases, end of message. By the way, humans are increasing the concentration of an important GHG dramatically. So temperature goes up. What is your problem with this simple fact?
  12. The BEST Kind of Skepticism
    52 Dale
    BEST does not refute any argument (natural or human). However, just the fact that they even mention AMO shows to me that someone there thought it possible. That shows doubt about the AGW evidence. And guaranteed Muller would have proofed every paper before it left, so the fact it's still in shows Muller isn't so strong in "human caused GW" belief that he removed it.
    This is a recurring trope with the 'skeptics' just now. I really hope they [you] hold on to it and continue to post it up... ... Muller has sucker-punched the 'skeptics' once; I'm pretty sure he's setting them up to do it again.
  13. The BEST Kind of Skepticism
    skywatcher @50: You point to SkS's Earth buildup of heat article, which shows ocean heat continuously rising to 2008 (end of graph). This is in direct contradiction to another SkS image showing OHC being flat from 2004 (http://www.skepticalscience.com/images/ocean_heat_content.gif). The flat period is also replicated in other locations, so it's hard to accept the Earth building up heat article on face value when it makes a mistake as obvious as that. CBDunkerson @51: "In the field of climate science, the consensus is unequivocal: human activities are causing climate change." http://www.skepticalscience.com/global-warming-scientific-consensus.htm Very much implies (the way it's written) that humans are THE cause of GW. The article automatically fingers CO2 as the culprit (when that article is read in the series as intended). BEST does not refute any argument (natural or human). However, just the fact that they even mention AMO shows to me that someone there thought it possible. That shows doubt about the AGW evidence. And guaranteed Muller would have proofed every paper before it left, so the fact it's still in shows Muller isn't so strong in "human caused GW" belief that he removed it.
  14. The BEST Kind of Skepticism
    Dale in #33: "...they say ... and that human involvement is most probably over estimated." Dale in #39: "Gee, so sorry for not getting the exact wording correct. ... And if it is natural variability then the human component may be over estimated." (emphasis added) As you somehow missed where you went wrong, it was in changing 'may be', which BEST actually said, to 'is most probably', which Watts and others have falsely claimed... though you 'strangely' refuse to 'condemn' this. It's a bit more than an 'exact wording' issue. Had they claimed 'is most probably' without evidence you can be sure people would be calling them on it. As to the 'may be'; "What's interesting is they didn't automatically finger CO2 as the culprit." Not particularly. If you have really read as much as you claim you should be aware that mainstream climate science doesn't automatically finger CO2 as the sole culprit. Twenty years ago even it being the main culprit was seldom an 'automatic assumption' in the literature, though that has become less true as the evidence that it is the main culprit has become overwhelming. And again... the BEST study makes no effort whatsoever to refute any of that overwhelming evidence. Nor to provide any evidence whatsoever for an alternative explanation. That people who started out making all sorts of false and insupportable claims about AGW would continue to make a few such claims even after their own research has disproven their previous self-delusions is not surprising. At least this time they were more careful to say 'may', though even that is unjustified given literally zero evidence.
  15. The BEST Kind of Skepticism
    Dale, I'd be interested if you could show me the horizontal or downward trends in the datasets you mention. Call me a real skeptic, but all the trends I plot on woodfortrees since 2000 start low at the left-hand-side and end high at the right-hand-side, ie are positive? This leads me to doubt your claims. As to the significance of such short segments of a temperature series, read the Santer paper, any number of Tamino posts (particularly Riddle Me This, or the post right here at SkS. If you're as scientific as you claim, you'll realise that insignificantly short time periods are not relevant when considering whether the trend has changed. You'll also be interested in the post detailing that the Earth continues to build up heat. As to your suggestion of reading 'both sides', it would be OK if the other side was actually doing science...
  16. Berkeley Earth Surface Temperature Study: “The effect of urban heating on the global trends is nearly negligible”
    You all have GOT to be kidding. You expect climate change denial to dry up and blow away because of this one study? Rick Perry's still talking about the damn Birth Certificate!
  17. The BEST Kind of Skepticism
    Albatross, thanks for the links, but I've read those articles a number of times in the past. I've been reading climate change articles for years, so that I can make up my own mind. I read a lot of information, from here, WUWT, RC, CA and even scientist blogs. I believe I cover all bases, and hopefully smart enough to dismiss alarmism and hype and get to that actual science (I avoid media releases for just that reason). That's where the truth lies, in the science. Doesn't matter how many times you say sea levels will rise 8 stories (Tim Flannery) or the surface records are corrupt due to siting (Watts), without proof that can hold up to process and due diligence it's just unvalidated waffling. It's the same with BEST, until their papers go through process and due diligence, it's unvalidated. Note, by unvalidated I do not mean incorrect. The survey results you presented are interesting, but what was the actual question asked? That's not clearly noted on the results. The results mean completely different things if the question was "Has the world warmed in the last 150 years?" or "Is the world still warming?" If the question is the later, then technically it hasn't according to HadCRUT, CRUTEM, NCDC, and the RSS, UAH satellite feeds since 2000 (GISS shows a slight warming). Or if it has, the trend is minuscule. And please save me the usual "2010 was the hottest on record" comments. Yes the decade is the hottest, but it's flat when compared to the rising trends of the 3 previous decades. I think of it as "the top of the curve". Whether it goes up or down is yet to be seen. In 3 years of talking climate change with people I know and people on the internet, I've come across no one who doesn't believe we've warmed at all. As for your final question, it's my experience that is a pretty loaded question at this site. I've been asked that question before and the context was always "do you believe what's written at SkS or not?" I am my own sceptic. I consider all articles (from both sides) sceptically till I've found confirming evidence from science. That is why I read information from both sides. I appreciate that if I only read information from one side my opinion will tend to lean that direction. So I read from SkS, RC and others, as well as WUWT, JoNova (more for an Aussie home flavor), CA and others. If that makes me a "denier" I'd rather be that, than 'persuaded' by limiting my information inflow to one side. And no, I will not join you in condemning Watts. I consider that poor form and bad manners, no matter who it is.
  18. Clouds provide negative feedback
    No, net feedback in the climate system is not required to be negative.
  19. The BEST Kind of Skepticism
    Dale, The "skeptics" and those who are in denial about AGW need to catch up with the science, the fact that internal climate variability can modulate the long-term warming trend has long been known by climate scientists. As the "skeptics" like to point out concerning CO2 and global warming, correlation is not causation (yet the fingerprints of anthropogenic warming are everywhere). Also, the way the AMO is defined introduces its own issues that complicates matters. Dale, I hope that you will join us in condemning Watts parroting misrepresentations concerning the correlation between the AMO and the global land temperatures the BEST papers on his web site. Either way the claim that "skeptics" do not question that the planet is warming is demonstrably false. Arguments "challenging" the warming currently rank 5, 7 and 9 on the most used climate myths. Those myths exist because "skeptics" and those in denial insist on repeating them. Also a recent survey in the USA shows that over 50% of Republicans believe that the global temperatures are not increasing [H/T ThingsBreak]. [Source] Another demonstrably false statement that "skeptics" are now making in their state of desperation is that the amount of warming caused by humans is unknown and that it is largely attributable to natural causes. First off, climate scientists are not attributing 100% of the observed warming to CO2, so "skeptics" claiming that are not being honest. Second, we have very good estimates that know that "a net anthropogenic warming of 0.49 to 1.12°C with a central estimate of 0.65°C warming of average global surface temperature." See here. Also see here and here and here. In reality, the people making a big deal about BEST are the "skeptics". They are besides themselves with panic, and even turning on each other. Seeing them trying to spin this and at the same time attack the BEST group is rather bizarre; but I must admit it is rather entertaining. Why are "skeptics" making such an effort to discredit, undermine and dismiss the BEST results if they agree that the planet is warming and that the global temperature records are reliable? No, they are in deep, deep denial of course, and that includes Mr. Anthony Watts and his apologists such Pielke, McIntyre and Monckton and Delingpole. etc. Now Dale, are you a real skeptic or a fake one?
  20. The BEST Kind of Skepticism
    By the way, the speculation in the BEST paper regarding the human component possibly being overestimated because of AMO contributions reminds me a whole lot of the McLean et al. paper making the same argument about ENSO. In both cases they de-trended the data in their analysis, and thus could not conclude anything about long-term warming causes. It's possible that since the speculation in the McLean paper made it to the published version, the same will happen with the Muller et al. paper. But personally if I was a reviewer, I'd make them remove it. I don't see what's gained through baseless speculation.
  21. The BEST Kind of Skepticism
    There's no question the importance of the BEST results has been way over-hyped, but only because the "skeptics" have for so long denied the accuracy of the surface temperature record. As for AMO, like ENSO it's an oceanic cycle that doesn't create heat and thus cannot cause a long-term warming trend. I wouldn't be surprised if the sentence in question is revised or removed during the peer-review process, because frankly it seems obviously incorrect IMO.
  22. The BEST Kind of Skepticism
    PeterS @44 You're kidding right? The sceptic goalpost for most of us is, and always has been, "sure, the world has warmed...... but WHY?" Everything else is basically just noise to the central question. And quite simply a lot of people whilst they believe the whole GHG situation, disagree with how some scientists claim it works. For instance, logarithmic returns on CO2 cannot cause runaway warming (used as an example, not to begin an argument). This applies to the BEST research. Sceptics don't care that they show global warming. We know that. What's interesting is they didn't automatically finger CO2 as the culprit. IMO, some sceptics have made too much about that one sentence regarding the AMO. But AGW people have also made a big deal out of the global warming confirmation. The MSM going on about scepticism being dead now since BEST confirms global warming? Reminds me how the other side of the MSM reacted to CERN's initial CLOUD announcements. Over-hyped.
    Response:

    [DB] "The sceptic goalpost for most of us is, and always has been, "sure, the world has warmed...... but WHY?""

    Umm, no.  You forget that the skeptic "It's not happening" meme is one of the foundational cornerstones responsible for the creation of this website.  See the relevant portions listed under the Taxonomy listing.

    "And quite simply a lot of people whilst they believe the whole GHG situation, disagree with how some scientists claim it works."

    By some you mean the vast majority of climate scientists?

    "What's interesting is they didn't automatically finger CO2 as the culprit."

    Straw man.  No one is saying that CO2 is the sole "culprit" in the warming.

    "But AGW people have also made a big deal out of the global warming confirmation."

    Actually this is just another audit.  The temperature records showing the global warming signals inherent in the data were confirmed years ago.  But the "skeptic" need to minimize the results of BEST is understandable given that the skeptic self-identity is tied up in the many years of denial they have maintained.

  23. Clouds provide negative feedback
    Bibliovermis, I know net positive feedback does not lead to runaway warming. "So, the answer to your question is no." Which question?
  24. IEA CO2 Emissions Update 2010 - Bad News
    The burning of high sulfur coal creates sulfate particles which block incoming solar radiation thus limiting temperature increases in the short term. How much sulfate effect is included in the IPCC A2 scenario? To what extent is the current economic downturn flattening the temperature growth curve?
  25. The BEST Kind of Skepticism
    Holy jumpin' jehosaphat! Have the denier goal posts been moved SO far, that now they are clinging to some speculative sentence in an article that the human component of "global warming MIGHT be SOMEWHAT overestimated"? Game over. Humans are contributing to global warming. And probably to a significant extent. I doubt arguing over whether its 30% or 70%, is going to comport with two decades of previous denialsim.
  26. The BEST Kind of Skepticism
    Dale, The leader of the BEST project, Richard Muller said this at a speech a few weeks ago: "Global warming in my evaluation is real and much of it, if not most of it, is caused by humans," --Richard Muller, Sept. 28, 2011 http://wsutoday.wsu.edu/pages/Publications.asp?Action=Detail&PublicationID=27853&PageID=21
  27. The BEST Kind of Skepticism
    Dale, please refocus on the science and spare us the tone. Your restatement of the BEST study was just that: a restatement. But in that restatement you changed the meaning significantly. When quoting please use "quotes" (and ideally italics to avoid any misunderstanding. And the Tamino post I linked in 37 above is well worth reading. Edit: Please also see Tamino's response to this comment over at Open Mind.
  28. The BEST Kind of Skepticism
    @40. I never said or implied any of that. I simply answered @29's question. You assumed the rest.
  29. The BEST Kind of Skepticism
    Dale, That's a pretty big if. Where's the evidence? Where is the logic? Where is there anything except for a desperate hope that it is true, simply because you don't want to believe otherwise, in the face of all evidence? What about this paper makes you personally believe that their inference is true? And why do you put so much weight into a single statement in a paper which as far as I knwo contains no data which would support such an assertion. A statement which is a mere "may," and if true only implies that AGW may be "overestimated" (they don't say by how much)? What sort of skeptic clings to a single, unsupported sentence in a single paper whose focus is not anything in the arena of that statement?
  30. Arctic Ice Volume is diminishing even more rapidly than Area
    Am I correct in saying that if the ice volume minimum trend continues its present course that sometime during the next decade the arctic will become ice free for some period of each summer? Are there any articles discussing the effect of SST change on lifeforms living in altered sea/ice environments. Thank You.
  31. The BEST Kind of Skepticism
    Gee, so sorry for not getting the exact wording correct. My point still stands though in response to @29 that BEST took a stab by pointing at AMO (whether it's GHG's or natural variability that influences it). And if it is natural variability then the human component may be over estimated.
  32. The BEST Kind of Skepticism
    It's interesting how the correlation (without causation) between the AMO and the global temperature signal has been highlighted. We have several issues: 1) identifying a cycle in a timeseries so short that few 'cycles' are present - add some aerosol cooling here, a little enhanced solar activity there, et voila we have the appearance of a 'cycle' within the warming trend. 2) the Atlantic (while large) represents a relatively small fraction of the Earth's surface. How does that drive global temperatures? 3) We have the issue of the direction of cause. The AMO correlates with global temperature. Without a mechanism, who is to say that global temperature drivers also drive AMO temperatures?
  33. Clouds provide negative feedback
    RW1, Net positive feedback does not lead to runaway warming (Venus result) anymore than net negative feedback leads to Snowball Earth. So, the answer to your question is no. If you do not understand why, you did not understand what you read.
  34. The BEST Kind of Skepticism
    Tamino has expressed the opinion that the warming apparent in the AMO is that of global warming itself. http://tamino.wordpress.com/2011/01/30/amo/ However, others share a different opinion and this matter is not yet considered consensus.
  35. The BEST Kind of Skepticism
    Further to Dale's misquote, ThingsBreak has a more detailed explanation. Seems that the 'misinterpretation' is coming from the GWPF via WUWT. What a surprise, eh ? (Not)
  36. The BEST Kind of Skepticism
    Dale, have you looked at a definition of the AMO lately? From Wiki: "The AMO signal is usually defined from the patterns of SST variability in the North Atlantic once any linear trend has been removed. This detrending is intended to remove the influence of greenhouse gas-induced global warming from the analysis." [my highlighting] Kinda tricky to see how the AMO will drive warming, when the warming trend has been removed from the AMO...
  37. The BEST Kind of Skepticism
    Dale wrote: "In the multidecadal oscillation paper they say the cycle fits AMO very well, and that human involvement is most probably over estimated." No, they don't. If you believe that paper says anything of the kind you have been misinformed or misunderstood something. What it says is that observed temperature fluctuations fit the AMO better than other commonly cited cycles (particularly ENSO). They also say that the ~0.55 C warming observed over the AMO cycle could be due to greenhouse gases or some unidentified other factor... and if it is some theoretical other factor then that could also play a part in the observed land temperature increase. They provide no evidence for another factor or against greenhouse gases. Basically, they identify a correlation in trends and then speculate on possible common causes without any analysis of those speculations or reference to other research on the matter.
  38. Clouds provide negative feedback
    DB, I already have Ray's book and have read a lot of it. I guess you're not interested in answering my questions?
    Response:

    [DB] If full understanding of the text was not achieved then perhaps you should place those questions over at RC where Ray has a presence.

  39. The BEST Kind of Skepticism
    Bern @29 BEST do take a stab at the cause of global warming. In the multidecadal oscillation paper they say the cycle fits AMO very well, and that human involvement is most probably over estimated.
    Response:

    [DB] "human involvement is most probably over estimated"

    I must have missed that part; my pardon.  My copy says:

    If the long-term AMO changes have been driven by greenhouse gases then the AMO region may serve as a positive feedback that amplifies the effect of greenhouse gas forcing over land.  On the other hand, some of the long-term change in the AMO could be driven by natural variability, e.g. fluctuations in thermohaline flow.  In that case the human component of global warming may be somewhat overestimated.

    And then in the conclusion:

    In conclusion, our analysis suggests that strong interannual and decadal variations observed in the average land surface temperature records represent a true climate phenomenon, not only during the years when fluctuations on the timescale of 2-15 years had been previously identified with El Nino events.  The variations are strongly correlated with the similar decadal fluctuations observed in the Atlantic Multidecadal Oscillation index, and less so with the El Nino Southern Oscillation index.  This correlation could indicate that the AMO plays an important intermediary role in the influence of the Pacific ENSO on world climate; alternatively, it might indicate that variability in the thermohaline flow plays a bigger role than had previously been recognized.

    [Emphasis added where bolded]

  40. Clouds provide negative feedback
    RW1, you seem rather desperate to demonstrate a net negative feedback for the whole climate system, not just clouds, yet how do you explain palaeoclimatic variations with a net negative feedback? Leprechauns? Positive feedback need not equal runaway feedback.
  41. Test your climate knowledge in free online course
    Thanks for giving us the link to the PICS site. A very nice communication tool! I liked it so much I put up my own article to highlight it at http://climatetruth.gather.com/ Keep up the great work, John (et al.)
  42. Clouds provide negative feedback
    DB, "Your question presumes that there is a current energy balance at the TOA; the best understanding of the science indicates otherwise." No, my question presumes the opposite - that there is virtually always an energy imbalance of some degree, especially over the more shorter time scales that the dynamic physical processes of water vapor and clouds operate. The imbalance is either energy in > energy out or energy in < energy out. You are aware that the system is almost never in perfect equilibrium at any given time or over any given time period, right? "You also do not define what physical process you refer to that is providing the "net negative feedback required for basic stability and maintenance". Energy balance is the sum of physical processes, not hypothetical ones." Yes, the planet's energy balance is the net result of all the physical processes (and feedbacks) in the system. Do you agree the net feedback that operates on all the physical processes in the system - whatever they actually are, is negative?
    Response:

    [DB] With all due respect, the last time we discussed this several threads ago, you first need to learn more about the physics of climate science before trying to bend them to your will.  To that end I also recommend Raymond Pierrehumbert's textbook "Principles of Planetary Climate".

    In any event, given the nature of your questions here, it is evident that you have not yet pursued that option.  That is your choice.  But that leaves you on your pre-existent orbit of asking the same questions repeatedly in the hopes that one day you might find an answer more to your liking.  All in all a non-effective path to greater understanding and a waste of other's time.  And indicative of your earlier statement that you were "not here to learn anything"

  43. Clouds provide negative feedback
    DB, Is net negative feedback required for basic stability and maintenance of the current energy balance or not?
    Response:

    [DB] Your question presumes that there is a current energy balance at the TOA; the best understanding of the science indicates otherwise. 

    Energy in ≠ energy out (energy in exceeds energy out).

    You also do not define what physical process you refer to that is providing the "net negative feedback required for basic stability and maintenance".  Energy balance is the sum of physical processes, not hypothetical ones.

  44. Clouds provide negative feedback
    CBDunkerson (RE: #192), "You argue that 'the notion' of positive feedback from water vapor cannot be reconciled with 'tightly constrained' temperature variations in various other cycles (e.g. ENSO, seasons, day/night, 11 years solar cycle, et cetera)." No, I'm arguing that positive water vapor feedback in conjunction with positive cloud feedback cannot be reconciled with how the planet's energy balance is so tightly - but dynamically, maintained.
    Response:

    [DB] "I'm arguing that positive water vapor feedback in conjunction with positive cloud feedback cannot be reconciled with how the planet's energy balance is so tightly - but dynamically, maintained."

    The casual reader will note that, in the absence of doing the physics and showing your work, your statement is devoid of substance and amounts to empty assertion without merit.

  45. Test your climate knowledge in free online course
    On further reflection, I think the question asked was: If the current rate of SLR stays the same, then how much would sea level rise by 2100 [over present]? At the current rate of 3.0 ± 0.4 mm/yr, I suppose the best answer would be 30 cm, of the possible answers offered. I’m very doubtful that 30 cm is realistic although it agrees with AR4 projections. The SkS page on this topic shows a range of 75 cm to 180 cm (depending on the scenario) based on findings reported in Vermeer 2009. The A1F scenario that we seem to be tracking looks to be headed for 140 cm by 2100, according to Figure 3, or 120 cm if the A2 scenario is preferred. [A very minor point: these numbers are referenced from 1990 so they should be reduced by 6 or 7 cm to put them into the present context.] SkS - How much will sea levels rise in the 21st Century? I won’t go into Dr. Hansen’s ten-year doubling time for ice sheet disintegration, somewhat of a thought experiment, but I remind you that he’s often ahead of his peers. He said the following in 2007:
    The nonlinearity of the ice sheet problem makes it impossible to accurately predict the sea level change on a specific date. However, as a physicist, I find it almost inconceivable that BAU climate change would not yield a sea level change of the order of meters on the century timescale.
    Hansen 2007 - Scientific reticence and sea level rise (pdf)
  46. Climate's changed before
    225, lancelot, 1. Yes. The term you want to search for is "hindcast" (e.g. "hindcast climate model"). But note that your specific parameters (+/- 0.5 deg C) may be too constrained. There are lots of parameters to be accurately modeled beyond global mean temperatures, and lots of ways in which a model may or may not be accurate, but in particular, models handle climate, not weather. It is nearly impossible to predict weather, and no model attempts to do so. In fact, models work using ensembles (multiple runs with the same starting conditions, which are averaged together). Also, we do not have accurate, precise measurements for starting conditions a thousand years ago. These must be inferred from proxies or just plain guesstimates. We also do not have accurate values for many inputs (solar irradiance, volcanism, etc.). These can only be guessed at. So getting things within any predetermined expectation ("a half a degree in June, 1980") is asking a whole lot, and in the end is not meaningful in evaluating the skill of the model. But yes, obviously one important way to evaluate the models is measure their ability "predict" what we already know has happened. Yes, scientists do this, and yes, models hindcast with enough accuracy to validate their ability to forecast as well. 2. Again, see the answer above. This isn't really a valid criterion. There is a lot more to climate than just temperature, and choosing a point in time is problematic (what if there's a real world ENSO event at that time, but not in the model run?). 3. I don't know that anyone has answered this question in exactly that way, because it's not really meaningful. Various events do affect climate to some degree (active volcanism, solar variations, etc.). There is no real "normal" temperature. Taking an average of the last 2000 years is of little value. Beyond this, proxies are difficult to calibrate and work with. While scientists have done a wonderful job filling in the blanks and trying to infer past temperatures, we just don't have enough global readings (proxies) with enough accuracy to compute anything like what you are asking.
  47. Clouds provide negative feedback
    lanC (RE: #189), "The earth radiates energy as E=epsilon*sigma*T^4, where epsilon is the emissivity (0.61) and sigma is the Stefan-Boltzman constant. If you increase the average earth surface temperature (287K) by one degrees you'll increase E by 3.3 W/m^2" Correct. Now, why specifically is the emissivity 0.61?
  48. Clouds provide negative feedback
    RW1 wrote: "Have you noticed that even when the system as whole warms to a significant degree like during an El Nino event, it always seems to revert to its pre-equilibrium state fairly quickly afterward? This is hardly consistent with net positive feedback acting on perturbations." So... because the daily cycle of temperature fluxes due to sunrise and sunset returns to its 'equilibrium' state in short order this is evidence against Summer temperatures being warmer than Winter temperatures? That is essentially the 'logic' you are presenting... 'if A shows steady fluctuations around a flat baseline then B cannot possibly show long term increases'. "Also, the temperature rising as the Sun comes up each day is not the result of net positive feedback acting on the increased incident energy." In part, yes... it is. Most of the temperature increase is due to the increased radiation. However, water vapor feedback also plays a part... as anyone who has lived in a very humid area would be able to tell you. A climate 'forcing' is just a change from a baseline. Most often we choose baselines from on yearly averages. However, it is perfectly valid to look at the incoming solar radiation over the course of a day with the daily average as the baseline. In such case, sunrise would represent a massive warming forcing. We can then look at feedback responses to this forcing... specifically, that warming forcing from sunlight will cause water to evaporate. Water vapor is a greenhouse gas. Ergo, this will create a positive feedback. Further, it is a positive feedback that we have known about and studied for centuries. We use the term 'relative humidity' because the amount of water vapor the atmosphere can hold increases as the temperature does... so the relative humidity is the percentage of the possible maximum water vapor content of the atmosphere for the current temperature. If the temperature goes up the amount of water vapor the atmosphere can hold increases as well. A long understood and thoroughly measured phenomenon. Now, if the temperature of the entire planet goes up... why wouldn't the same feedback apply? If the planet's atmosphere is warmer it will hold more water vapor. That water vapor will produce more greenhouse warming. You argue that 'the notion' of positive feedback from water vapor cannot be reconciled with 'tightly constrained' temperature variations in various other cycles (e.g. ENSO, seasons, day/night, 11 years solar cycle, et cetera). I am saying that there is no logical way to conclude that water vapor will not be a positive feedback, because it is always a positive feedback to warming.
  49. Clouds provide negative feedback
    RW1, You have now demonstrated extreme ignorance on climate science (a complete failure to understand Stefan-Boltzmann, the Planck response as a feedback, and the way that we know that this response is 3.3 W/m2 per degree K). At this point, you must recognize the need to study and learn a whole lot more before you "authoritatively" comment any further on things that you clearly do not grasp.
  50. Human CO2 is a tiny % of CO2 emissions
    Sphaerica@212. Exactly. You appear to understand perfectly. The numbers I calculated were based on the assumption that the extra sucking applies only to anthropogenic CO2 and the new magical natural source that looks just like anthropogenic CO2 (i.e., same isotopic signature, etc.). The numbers I present say that if this removal ratio is 99%, then this mysterious natural source is 49x larger than the anthropogenic one - i.e., the 30 Gt anthropogenic source is running in parallel with a natural source of 1470 Gt. Kind of hard to miss in the grand scheme of things, since we seem to be able to identify the long-existing natural sources of much smaller quantity than this. This new source also seems to be rising at the same rate as anthropogenic CO2. Another astounding coincidence. ...but at least you have a conjecture as to the source. Unlike the "skeptics". And as muon points out, the same logical applies to any new sink we haven't noticed - it is "emerging before our very eyes". It has some magical property that allows it to turn on and grow at just the right rate. ...but muon's hypothesis seems a bit far-fetched. I think it is more likely that Sphaerica's alien race has introduced a cap-and-trade scheme, and some enterprising alien has realized that they can make oodles of money by scarfing CO2 out of our atmosphere and get credit for sequestering it. Unfortunately, the same conspiracy that made up the AGW hoax is also hiding the fact that we've made contact with these aliens, and have one of their teleportation devices stored at Area 51. We're not allowed to use it to solve our problem. [Yes, I know that it is inconsistent to have the same conspiracy both make up the problem and hide a real solution to the same problem. In the People's Republic of Made-up-istan, consistency is not a legal obligation.]

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