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Comments 130051 to 130100:

  1. Climate's changed before
    ps This agrees with earlier work done at Berkeley, from a 2005 article in the San Francisco Chronicle: "Mass extinction comes every 62 million years, UC physicists discover" David Perlman, Chronicle Science Editor Thursday, March 10, 2005
  2. Climate's changed before
    David Climate changes ineither direction causes extinction events. But it is a matter of degree. Warming opens up new environments at the same time as it makes existing ines more harsh. What happens is that life follows the environment. If it gets warmer life shifts poleward and colder it shifts towards the equator. This paper might help: Long-Term Cycles in the History of Life: Periodic Biodiversity in the Paleobiology Database Adrian L. Melott* Department of Physics & Astronomy, University of Kansas, Lawrence, Kansas, United States of America Abstract Time series analysis of fossil biodiversity of marine invertebrates in the Paleobiology Database (PBDB) shows a significant periodicity at approximately 63 My, in agreement with previous analyses based on the Sepkoski database. I discuss how this result did not appear in a previous analysis of the PBDB. The existence of the 63 My periodicity, despite very different treatment of systematic error in both PBDB and Sepkoski databases strongly argues for consideration of its reality in the fossil record. Cross-spectral analysis of the two datasets finds that a 62 My periodicity coincides in phase by 1.6 My, equivalent to better than the errors in either measurement. Consequently, the two data sets not only contain the same strong periodicity, but its peaks and valleys closely correspond in time. Two other spectral peaks appear in the PBDB analysis, but appear to be artifacts associated with detrending and with the increased interval length. Sampling-standardization procedures implemented by the PBDB collaboration suggest that the signal is not an artifact of sampling bias. Further work should focus on finding the cause of the 62 My periodicity.
  3. Tuukka Simonen at 21:30 PM on 2 March 2009
    Svensmark and Friis-Christensen rebut Lockwood's solar paper
    Here... At the page 3 there is a graph with words: “It may be the sun: a strong anti-correlation between intensity and radiosonde temperatures over the past 50 years. Source: Svensmark and Friis-Christensen, 2007.” He only shows the lower part of the graph you have in this page and forgets that the warming trend as well as volcanoes, ENSO and other stuff have been removed. You can even see parts of the numbers of the upper graph since the image is cut without further photoshopping. :D What a douchebag.
  4. David Horton at 19:20 PM on 2 March 2009
    Climate's changed before
    "So it seems that the most poleward areas were hit hardest, no?" Well no, the hardest hit were those where a shift in climate to hotter drier times led to environmental conditions that large species couldn't cope with. And in addition on the continents whose geography precluded the formation of refuge areas - which is where Africa, straddling the Equator, comes in - whichever way the climate zones move in Africa you are always left with areas that can support megafauna. I am really not sure why you think that cooling conditions causes extinctions unless you think that this means global warming is a good thing. If that is the case you are going to be sadly disappointed.
  5. HealthySkeptic at 17:17 PM on 2 March 2009
    The Mystery of the Vanishing Ocean Heat
    Chris, Quibbling over semantics is not the same as pointing out scientific errors. Whether or not the IPCC collected or collated the Hong Kong data is unimportant, they used it in their reports. Simply calling Dr. Nils-Morner a liar does not prove your case. If anything, it detracts from it. You talk about "making an effort to establish reality", yet you use the same tactics as the creationists use to defend their warped view of reality... simply dismissing anything that does not match your AGW paradigm and branding as liars any scientists who disagree with you along the way. Shame indeed!
  6. HealthySkeptic at 16:54 PM on 2 March 2009
    Misinterpreting a retraction of rising sea level predictions
    Chris, LOL! Talk about creative interpretation of the data! Unless there is a clear and continuous upwards trend in a set of data, applying a linear trend to it means absolutely nothing. This sort of misinterpretation is a trap you young players. There is no continuous upwards trend from 2002 to 2007 (which represents 60% of the data). A linear trend of this region is dead flat! If 1998 was such an "anomalous year" why do the values from 2002 to 2007 statistically differ very little from the 1998 value, and how does this fact support a "warming" trend?
  7. Christmas cartoon on melting North Pole
    Quietman Re: #21 Perhaps you could give specific examples where "AGW alarmists" have engaged in denialism w.r.t. any of the list of items you give in post #19. Otherwise it becomes mere cant on your part, and I'm sure you would not wish to be accused of that.
  8. Is Antarctic ice melting or growing?
    Re #52 Good Quietman, if you were prepared to read other's posts carefully and not jump to erroneous conclusions you could have avoided a whole load of unnecessary "argumenting". The fact that systems in the natural world may or may not reach equilibrium, however one considers it useful to define this (i.e. "equilibrium") for a particular circumstance, doesn't mean that "equilibrium" and "thermodynamics" are not fundamental concepts without which it would be difficult, if not impossible, to understand natural systems. Have a read of my post #29 from all those weeks ago and see if there really is anything there that you really think it's worth arguing about....
  9. Climate's changed before
    David Re: "but did include some giant emu-like birds, and some giant reptiles." Yes I am familar with these and I recall a large carniverous "roo" as well. The reptiles are / were varinids and there are claims made to their survival. South East Asia and the Indian subcontinent still have their large species (elephants, bengals and 8 to 10 meter pythons (with claims to larger). North America and Eurasia definately did not fare well, I agree. South America lost some of it's megafauna but they were not truely giants and many survived (again with rumors of still more). So it seems that the most poleward areas were hit hardest, no?
  10. Is Antarctic ice melting or growing?
    "through southwestern WI and the door penininsula " I meant to say southeastern WI. Southwestern WI has it's own beauty - I'd especially recommend the drive from Madison to Dubuque. And if you're in the Madison area, you've gotta go just north through Sauk City and explore the Baraboo range (made of beautiful erosion-resistant Baraboo quartzite) - Devil's Lake, Parfrey's Glenn. See "Roadside Geology of Wisconsin", Dott and Attig.
  11. Is Antarctic ice melting or growing?
    "But they are not constants, they are chaotic variables." Please see my comments (and the post itself) here: "Butterflies, tornadoes and climate modelling" http://www.realclimate.org/index.php/archives/2008/04/butterflies-tornadoes-and-climate-modelling/langswitch_lang/sw (my comments: 50-52,65,73) ---- "This is a part of a "joining of ancient plate boundaries"" It's more complicated than that, though. There were many early collisions to form the Superior province, and then add on to it (Marshfield continent and Penokean orogeny, etc.). The most prominent system of faults underlying Lake Superior (and extending toward Kansas and eastward as well) formed as the Keweenawan rift (extensional), which did later become compressional features, but never actually became subduction zones. But erosion and sedimentation can cover up older features. Part of the reason for the Great Lakes is glacial erosion, although underlying geology certainly influences how much erosion occurs where. And the density of the basalt from the rifting tends to make the land lower than it otherwise would be. And there is the Wisconsin arch (or dome?) and the Michigan basin... the depression of the Michigan basin has tilted strata upwards going away from it; erosionally resistant strata (Silurian dolomite, is it?) can form escarpments, such as the Niagara escarpment. A string of escarpments wraps around the Michigan basin, through southwestern WI and the door penininsula (I think it's all called the Niagara escarpment - not to be confused with the Niagara fault, a much older feature not connected to the falls), and is what Niagara falls plunges over. Niagara falls is between lakes Erie (the shallowest - it's only into looks) and Ontario, so Lakes Michigan and Huron rising a few meters to be above Lake Superior would not reverse the flow of Niagara falls. "The mountains in Vermont are growing again" I hope the sugar maples are growing much faster.
  12. Arctic sea ice melt - natural or man-made?
    "In the absence of other information, Mann, et. al.'s word on the subject surely must be given equal weight as McIntyre-McKitrick's statements." or you could look at the actual papers...
  13. Arctic sea ice melt - natural or man-made?
    (solar wind): Without a known physical mechanism, you could also look for statistically-robust correlations (as opposed to a one-off match-up) between solar wind and one or more climate-related variables. However, you'd have to compare this to such correlations with TSI to isolate the relationship... in other words, try looking at a component of variations in the solar wind that do not correlate with TSI or other known climate forcings... "Plug any number into the hockey stick and it will always be a hockey stick. " Not so. That may have been the case with McIntyre-McKitrick's work (I don't remember all the details off hand), but not Mann's. In the absence of other information, Mann, et. al.'s word on the subject surely must be given equal weight as McIntyre-McKitrick's statements. Other information: many other studies yeild similar results. Similar but not exact. Maybe that's the problem you see. Other results do not look exactly like a 'hockey stick' - but the importance of the results is that there has been a sharp rise in temperature in the later portion of the 20th century that is anomalous (in combined speed and magnitude) relative to the rest of the record, and late 20th century temperature values are likely the highest for as far back as one can go in these several-century to 2000 year reconstructions (there may have been another peak in warmth earlier in the Holocene but we may have gone above that already, too; at least we are close to it. And not far away from the warmth of the previous interglacial, for that matter. None of which by itself proves that this is anthropogenic and that warming will continue at least until the atmospheric CO2 level (plus other greenhouse gases, minus aerosol cooling, plus variations in solar TSI, etc, weighted by radiative forcing and efficacy, taking into account lag-time and longevity of responses and feedbacks, averaged over internal variability) stops rising. But the paleoclimatic record is not all of the available information).
  14. Is Antarctic ice melting or growing?
    Patrick This is the article on Huron. http://www.livescience.com/animals/090224-great-lakes-extremes.html
  15. Philippe Chantreau at 18:19 PM on 28 February 2009
    Arctic sea ice melt - natural or man-made?
    Focusing on people? Like "skeptics" focus on Mann and Hansen? You brought up citations by Morano and Spencer, not me. Heck you even throw in Robinson and the OISM, and Beck. Since you showed plenty of "focus" on the persons of Mann and Hansen, why should I think twice about "focusing" on all these funny characters you bring up? Spencer's paper? What paper? A blog post is not a paper. However, it can indicate what the author is capable of. Didn't prove anything eh? Did you prove that solar winds are heating things up? I admit that would be a lot of work, let's bring the goals down: did you describe any kind of vague mechanism that could make that possible? Proof is a strong word. In fact, some would say that science does not provide any such thing.
  16. Climate's changed before
    "I was not aware of particularly large mammals in Australia" - no they became extinct some 25,000 years ago. It was mainly mammals, but did include some giant emu-like birds, and some giant reptiles. India I'm not sure about. There were extinctions in South East Asia though, as well as the Americas of course. The equivalent large animals of Africa (elephant, rhino, giraffe, lion etc) all survived for reasons which are debated. I think it is because Africa straddles the equator and climate change therefore always left some refuge areas.
  17. Climate sensitivity is low
    chris I was asking if that was the original paper that you referred to. A little testy?
  18. Is Antarctic ice melting or growing?
    ps The mountains in Vermont are growing again.
  19. Is Antarctic ice melting or growing?
    Re: "although I think the centers of some of those lakes are actually quite a bit deeper than 200 feet, as I recall (is the deepest point in Lake Superior below sea level?))." This is a part of a "joining of ancient plate boundaries" so it was ancient shoreline and possibly a subduction zone millions of years ago. Yes, I have no doubt that the bottom is below sea level. There is currently an article featured on LiveScience but I can't open the site to get a link. They decided to change their format and screwed their server up royal. I can't even sign in. If it ever comes back online I will post a link for you. The high side of the falls is the american side so the canadian side had to slide under it with the compression from the atlantic and arctic ridges. Erie and Huron would be right on that subducted part of the canadian shield.
  20. Is Antarctic ice melting or growing?
    Re: "Yes, but the goal posts tend to stay within a particular part of the field when boundary conditions (external forcing) are constant" But they are not constants, they are chaotic variables.
  21. Is Antarctic ice melting or growing?
    Patrick Re: "And has the lake overflowed, spilling back into Lake Superior (reversing the normal flow)?" Niagara Falls reverse flow? I don't think so. ps It's salt water. The reports says that they have assumed the the salt is carried up with a fresh water current. But you and I both know what "assume" means.
  22. Arctic sea ice melt - natural or man-made?
    ps The alarmists will always defend the hockey stick but everyone already knows it's flawed. Same issue, piss poor statistical modelling.
  23. Arctic sea ice melt - natural or man-made?
    Patrick Mann's worhas been disproven in the same manner that Spencers paper was. Plug any number into the hockey stick and it will always be a hockey stick.
  24. Arctic sea ice melt - natural or man-made?
    ps I wasn't changing the subject, just pointing out that your insistance on focusing on people is exactly the tactics that alarmists always use. You personally did not prove anything. You are taking someone elses word. Patrick already showed me what he considers the error in Spencer's argument and I believe him.
  25. Arctic sea ice melt - natural or man-made?
    Yes Philippe, only Sceptics screw up, Alarmists never do. I think the horse has been dead for a while already.
  26. Philippe Chantreau at 13:03 PM on 28 February 2009
    Arctic sea ice melt - natural or man-made?
    Are you yrying to change the subjet? You don't seem to get it. Spencer does not even realize that his mathematical argument is moot. He is showing what he believes to be some form of data analysis, that he believes demonstrate something when the effect shown is an inherent property of the mathematical treatment. It does not analyze the data at all, and he has no clue about it. PhD or not, he does not understand what he's doing. That's way beyond anything Mann was ever accused of, real or not. There is no way that something like that would ever make it through peer-review, even if Legates worked on it with buddies of his. The fact remains that Spencer's media communications on attribution of the rise in CO2 are pure fantasy and contradicted by all the available evidence. Spencer has evidently not tried to publish anything about it, he knows better. The fact remains that Spencer and Christy's handling of the UAH/MSU errors was way below anything necessary for the so-called skeptic crowd to scream fraud all over the internet. Yet I don't hear your voice on that. Could that be an example of one-sided skepticism? My questions about Morano still stand. What exactly was the thought process there if any? My questions about the solar wind still stand. I'd love to hear of a possible mechanism with even a vague idea of the resulting heat budget.
  27. Is Antarctic ice melting or growing?
    "That IS EXACTLY the point I am trying to make. It's always TRYING to reach equilibrium but NEVER CAN because the goal posts keep moving. " Yes, but the goal posts tend to stay within a particular part of the field when boundary conditions (external forcing) are constant - in other words, on time scales longer than internal variability, there is a tendency to be near a definable long-term equilibrium. Saying that the climate system ever reaches equilibrium precisely would be wrong, but it can be a good approximation.
  28. Is Antarctic ice melting or growing?
    It isn't surprising that a lake would have some connection to groundwater flows. Many do. (I have heard that natural processes may cause the Great Lakes to largely dry up over the next 20,000 years or so - but that was way back in elementary school. Not that it would be a linear process, but ... I'm guessing that would be on the order of a 1 foot drop per century - although I think the centers of some of those lakes are actually quite a bit deeper than 200 feet, as I recall (is the deepest point in Lake Superior below sea level?)).
  29. Is Antarctic ice melting or growing?
    "but then we find water is entering also from the lake bottom through "sinkholes". " And has the lake overflowed, spilling back into Lake Superior (reversing the normal flow)?
  30. Arctic sea ice melt - natural or man-made?
    "So that means that you will never trust Mann again as well?" Mann's results have been largely confirmed; McIntyre and McKitrick's (spelling?) analysis was flawed. Roy Spencer's analysis is sloppy and unconvincing.
  31. Does model uncertainty exagerate global warming projections?
    chris It is a compressed graph of every other graph I have seen. Those low points are all known Ice Ages. The inaccuracy you see is the compression ie. they have done some averaging in order to get it to fit. Re: "For example we all know that the temperature hasn't dropped smoothly from "22 oC" to "12 oC" during the past several million years!" This is a direct result of that compression. Pro AGW charts do exactly the same type of compression but I don't see you complain about them. At the bottom left of the chart you will note the source of the data. The temp data is from a site with some of the best Paleomaps I have ever seen and often reproduced for text books. And you call me dishonest.
  32. It hasn't warmed since 1998
    thewags The far north has a couple of geologoc features that never seem to be talked about. The midatlantic ridge does not stop in the north atlantic but continues on under the Arctic ice pack. A paper last year stated that the activity had increased and that the ridge was spreading faster. The subduction zones are along the northern faces of Greenland to Alaska. So naturally the northernmost zones are showing increased volcanism. With all this increased tectonic activity I would expect major climate change at the north polar region. I truely can't understand why the IPCC has not taken this into account.
  33. We're heading into an ice age
    Mizimi Yes that was the first piece I saw that got me interested in the hypothesis. Mackey said the test period would be 2007-2011 and so far it's on the money. It's also the ONLY paper that predicted the cold snap, all the other articles and papers at that time said exactly the opposite. (I kept all the failed forcasts in a file to serve as bad examples for future generations). ps The green house is on hold until the ice melts. Right now I'm waiting on delivery of a larger snow blower that I can mount off the PTO on my tractor. Snow has been way too heavy for the gas fired one and too deep to plow, I have been using a bucket loader all winter to shovel it off and it's ruining my driveway. So I'm going to have to resurface it when everything finally melts. But I am planning to go with the blue plastic for the roof.
  34. Is Antarctic ice melting or growing?
    Patrick Re: "Is the level of the nearest large body of water at all predictable?" Not in an open system. Best example is lake Huron. Snow melt, rainfall and evaporation are taken into account but then we find water is entering also from the lake bottom through "sinkholes". - Remember that discussion we had on Ned Potters blog about why the sea level has not changed as expected?
  35. Is Antarctic ice melting or growing?
    chris Re: "So in our example of enhanced solar forcing, the Earth might be a bit warmer two years after the onset of enhanced solar, and likely warmer still 10 years later, but the temperature rise would be far short of the eventual (equilibrium) temperature rise than might take many decades to come near to equilibrium and many 100's or even 1000's of years before the oceans and ice sheets responded fully to the change in solar forcing" That IS EXACTLY the point I am trying to make. It's always TRYING to reach equilibrium but NEVER CAN because the goal posts keep moving.
  36. Arctic sea ice melt - natural or man-made?
    I guess what's good enough for Mann should also be good enough for spencer. So that means that you will never trust Mann again as well?
  37. Climate's changed before
    David Only the Australian mammals? I was not aware of particularly large mammals in Australia. As for all the continents except Africa, what about the Indian subcontinent?
  38. Climate's changed before
    No, I don't mean the Berkeley paper, I mean my own work on Australian mammals, but I'm glad they agree. Seehttp://www.blognow.com.au/mrpickwick/History_Conquerors/ for an extended discussion on Australia and more generally. Whatever happened to the Neanderthals is a separate (though possibly related) issue to what happened to all these big mammals on all the continents except Africa.
  39. Climate's changed before
    ps This link will take you to PLos One when they are back online. Then just type in "neandertal" in their site search for the paper.
  40. Climate's changed before
    David You must mean the Berkeley paper: Climate Change Plus Human Pressure Caused Large Mammal Extinctions In Late Pleistocene ScienceDaily (Oct. 4, 2004) — Berkeley - A University of California, Berkeley, paleobiologist and his colleagues warn that the future of the Earth's mammals could be as dire as it was between 50,000 and 10,000 years ago, when a combination of climate change and human pressure resulted in the extinction of two-thirds of all large mammals on the planet. LOL - That's from Berkeley back in 2004! I don't know if I would trust them, but I can't access the original paper. That is a shame. There is also an ongoing argument about a couple of impacts right around then, one on land in the northern U.S. (I forget exactly where) and another in the Atlantic near Brasil (again I don't remember exactly where, I'll try to find the articles). I agree when something goes awry with the normal stabilising mechanisms things happen. But it's not something we have a lot of control over. But "causes far more problems to water based life forms than cold climate." I have to disagree with. Read that paper when PLos One comes back online (they are just doing maintenance) and look at the graphs. Both Neandertal and our ancestors took a real nose dive at H4, we were lucky to recover, neandertal wasn't so lucky.
  41. Climate's changed before
    Um yes, the Neanderthals are an interesting case since they involve "creatures" with similar culture and lifestyle and bigger brain than us. Clearly the interaction between us and them was complex. Climate change may well have played a role in Neanderthal demise either directly or indirectly, as may interaction with H. sapiens sapiens. But I am talking about the extinction of the megafaunas - in Europe adapted to cold conditions (eg woolly mammoth), in Australia to cool wet conditions (eg Diprotodon). And extinctions due to strikes from space? Dunno. I was once reasonably happy with the dinosaur demise theory, but even that one I have my doubts about now. I reckon CO2 build up with methane release as the planet warms up is a better bet for all of them, but that is just me. But whatever the cause of the past great extinctions, they are really just cautionary tales about what can happen to this planet when something goes awry with the normal stabilising mechanisms. Makes a nonsense of the denialist view that us puny 6 billion humans spewing ever more CO2 into the air couldn't possibly alter the climate. I think we are in for a least the late Pleistocene (yes, pre-Holocene if you like) nastiness, and quite possibly much worse. And you will find that hot climate (plus dry in Australia) causes far more problems to water based life forms than cold climate.
  42. Climate's changed before
    David I knew I had read a little about it. This is from my file. PLos One is down right now so I can't give you a link. But here is the Abstract. Neanderthal Extinction by Competitive Exclusion Banks,et.al Background: Despite a long history of investigation, considerable debate revolves around whether Neanderthals became extinct because of climate change or competition with anatomically modern humans (AMH). Methodology/Principal Findings: We apply a new methodology integrating archaeological and chronological data with high-resolution paleoclimatic simulations to define eco-cultural niches associated with Neanderthal and AMH adaptive systems during alternating cold and mild phases of Marine Isotope Stage 3. Our results indicate that Neanderthals and AMH exploited similar niches, and may have continued to do so in the absence of contact. Conclusions/Significance: The southerly contraction of Neanderthal range in southwestern Europe during Greenland Interstadial 8 was not due to climate change or a change in adaptation, but rather concurrent AMH geographic expansion appears to have produced competition that led to Neanderthal extinction.
  43. Climate's changed before
    sorry, i screwed up the link: This should work.
  44. Climate's changed before
    Ok, I am getting caught up. It was a series of glacations and interglacials. Yes I did read about this period to some extent (I have a terrible memory). The chart at Wikipedia is a good refresher. I'll brush up on it.
  45. Climate's changed before
    Just to refresh my memory you are talking about an interglacial within the Neogene-Holocene Ice Age? The Pleistocene was the last period prior to the Holocene and prior to H4, correct?
  46. Climate's changed before
    pps Calling sceptics "deniers" is the same as calling you an alarmist. I am sure that you don't like it either.
  47. Climate's changed before
    ps I am not as familiar with the Pleistocene, I have been studying the Paleocene-Eocene-Oligocene periods recently but have not gotten as far as the Pleistocene. What do you have so far?
  48. Climate's changed before
    David Someone essentially called John a liar (in a nice enough way) in the Arctic melt thread and he has been very quiet since. I side with John but I'm a liar too. The Permian extinction is obviously the most interesting. I'll assume that you have read "Gorgon" already since it is so pertinent. OK, the obvious factor is the Siberian traps. Large volcanic fields erupting for a very long time spewing all sorts of poisons into the atmosphere. But (from Gorgon) the sea extinctions (something like 90%) happened in a different time fram from the land extinctions (Somewhere around 75%). Sorry I don't remember the exact numbers. Well what caused the traps to erupt? In both the PT and KT extinctions we have evidence for very large impactors on the opposite side of the earth preceding the eruption of the traps. The reason for the extinctions is fairly obvious (two incidents and two extinction events, the second event caused by the first). BTW the same actually happened at the KT, Bakker points out that the dinosaurs were already in trouble by the KT event.
  49. Climate's changed before
    Well, the Late Permian comes immediately to mind. The period which is my own research speciality is the late Pleistocene. The cold period (Europe) and relatively wet period (Australia) was a time when large mammals flourished. The change over to a warmer and drier time saw the loss of numerous species. This extinction event is going to be mirrored by what is going on now. But more so, because the change which took hundreds, perhaps thousands of years then (ie starting some 25,000 years ago), is going to be replayed in the space of a few decades in the 21st century. I swore I wasn't, on the basis that life, and an equable climate, is much too short, going to argue with denialists any more, but here I am, can't help myself I suppose. BY the way, does anyone still following this thread know what has happened to the owner of this blog? It feels like we are playing around in a deserted house, the owner curiously absent.
  50. Is Antarctic ice melting or growing?
    re #43/47 You're arguing fruitlessly through a semantic confusion over the concept of "equilibrium". Why not just go back and read my post #29 where I explained explcitly the use of the concepts of equilibrium and thermodynamics in consideration of natural phenomenon. If you think there's something wrong with the descriptions I gave there then address those specifically. But please stop tedious argumentation based on semantic misunderstanding. As for "equilibrium sensitivity" that's also a straightforward and easily understood concept. Imagine the sun started to irradiate more strongly. I'm sure we'd agree that the Earth's temperature would rise; we could easily calculate the eventual temperature rise (x oC). Would the Earth become x oC warmer instantaneously? No. x oC would be the temperature rise once the various elements of the climate system came to a new equilibrium with the enhanced forcing. It's useful to consider this in terms of an equilibrium rise since the various elements respond on very different time scales. The troposphere would warm initially quite quickly..the water vapour concetration would rise fairly quickly to give an amplification of the solar warming...the oceans would take a long time to come near to equilibrium with the enhanced forcing. Slow ice sheet retreat would give a further slow feedback amplfication through albedo effects...and so on. That's what "equilibrium sensitivity" refers to. We can contrast this with "transient responses" that relate to the short term responses to forcings under conditions that are far from equilibrium (but tending towards a new equilibrium state). So in our example of enhanced solar forcing, the Earth might be a bit warmer two years after the onset of enhanced solar, and likely warmer still 10 years later, but the temperature rise would be far short of the eventual (equilibrium) temperature rise than might take many decades to come near to equilibrium and many 100's or even 1000's of years before the oceans and ice sheets responded fully to the change in solar forcing None of this precludes the obvious point that any other cyclical or stochastic elements of the climate system that causes short term temperature fluctuations still apply (as I said in post #29).

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