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thingadonta at 14:23 PM on 23 July 2009Climate time lag
RE: 174: "the sun is so dominant that it just doesn't matter". Yes, this is my position. I think the relative effect of increasing C02 on T in the atmosphere, ie by ~0.01% (ie ~280-390ppm) is very small. EG 1: C02 rise only 'correlates' with 2/4 T step changes since the 19th century (~1900-1940, 1978-1998), whereas the solar increase correlates with 3/4 (1900-1940, 1940-1978, 2000s-2009), so the sun is at least as dominant. Its ideology, not data, to claim that c02 is more dominant, from this simple correlation alone. The problem humans have, is to disentangle the relative effects between the sun and c02 on recent T-I wish it wasnt like this, I wish the sun had cooled or stayed the same in the last few hundred years so we would know the relative contribution, but because of various forcings and so on, nobody really knows or sure. IPCC's '90% certainty' is ideological bureacuratic convenience, nothing more. EG2. To discount changes in the sun as only having a very minor effect on T is not valid, because similar 'very minor' effects have produced large-scale T changes before, so the earth MUST be very sensitive to minor solar changes. However similar changes in c02 in the past have not driven T changes, so it is precarious at best to assert that C02 rise is dominating recent T changes. Th physics of c02 on heat in the amosphere is not incorrect, it is the relative contribution to recent changes that is the issue. I personally think, like the NIPCC, that the IPCC have got it backwards, c02 has less than 10% effect on recent T changes, and the sun dominates. EG3. Have a look at human history- a mountain pass in Europe recently (2003) became free of ice/snow revealing 4 previous times it has been open in the last 5,000 years. None of these previous openings were driven by c02, all by very small changes in the sun (the 1500 years solar cycle-in which we are currenly in a warming trend). So, we know small changes in the sun can do it, whether c02 can singnificantly drive T is not supported by previous times c02 was high (such as in previous interglacials-no 'runaway greenhouse', and during previous geological periods). Ref: "Unstoppable global warming evey 1500 years", F. Singer and D.Avery. NIPCC's 'Climate reconsidered' report, downloadable PDF at the Heartland Institute website. -
shawnhet at 05:54 AM on 23 July 2009Climate time lag
"I don't think so, shawnet. Again you're ignoring the fundamental element of science which is evidence. I'm generally agreeing with the evidence-based science. You seem to be rather uninterested in this. What I'm disagreeing with is bogus arguments and misrepresentation in the two sources you have introduced to this thread (I have no problem with the Harrison work you've referred to – he seems to be doing solid science without the fatuous hyperbole of your main sources). You're happy to cheerlead for dodgy "science". Fine....but you should expect that skeptical individuals are very likely to point out its flaws." It is fairly tedious to talk to someone who interprets any disagreement with themselves as dodgy science or whatever. The fact is, differences of opinion don't make either side of a scientific debate dodgy or whatever pejorative you wish to use. Calling something dodgy isn't pointing out its flaws. It is pretty obvious that there is much more detailed examination of the CRF-climate link in the Kirkby review than you have taken time to acquaint yourself with. However, rather than look at the totality of the evidence, it is much simpler to call it pseudoscience(when the worst you can offer is that he uses a different TSI reconstruction than you). You have offered no coherent objection to the central point of the Kirkby review which is that there appears to have been an amplification of solar effects on climate operating at various time schemes in Earth's history and that one way to see that connection working is by some sort of connection btw CRF and climate phenomena. Kirkby isn't saying the link is established, just laying out the reasons why he thinks it is worth exploring. ""Now perhaps you're suggesting that while these analyses are bogus, maybe some other arguments are more convincing. Fine. Let's have a look at them. You say "the long term correlation btw CRF and climate makes no sense without some form of solar amplification.". Which long term correlation? Why, exactly, does this make "no sense without some form of solar amplification"? " This paragraph makes me think that you aren't even reading what I write. There must be at least a dozen papers delineating the long term correlation btw solar proxies and climate events in the Kirkby review and I know we discussed the Bond paper already. The fact is, these papers lay out climate events whose magnitude is much greater than can be explained by variation in solar irradiance alone, but that are still well correlated to CRF. And, as I have said before, it is not that your papers are bogus, it is that, by and large, they don't deal with fundamental causes (for instance, they say THC is responsible without saying why THC changes happen). There is no contradiction btw saying both that a climate-CRF link and a THC change are responsible(if the climate CRF is indirectly responsible for THC changes). -
Robbo the Yobbo at 04:11 AM on 23 July 2009Climate time lag
David - denying the reality of decadal climate variability is, well, denying reality. Swanson and Tsonis - ‘The subject of decadal to inter-decadal climate variability is of intrinsic importance not only scientifically but also for society as a whole. Interpreting past such variability and making informed projections about potential future variability requires (i) identifying the dynamical processes internal to the climate system that underlie such variability (seee.g. Mantua et al. [1997]; Zhang et al. [1997]; Zhang et al. [2007]; Knight et al. [2005]; Dima and Lohmann [2007]), and (ii) recognizing the chain of events that mark the onset of large amplitude variability events, i.e., shifts in the climate state. Such shifts mark changes in the qualitative behavior of climate modes of variability, as well as breaks in trends of hemispheric and global mean temperature. The most celebrated of these shifts in the instrumental record occurred in 1976/77. That particular winter ushered in an extended period in which the tropical Pacific Ocean was warmer than normal, with strong El Niño-Southern Oscillation (ENSO) events occurring after that time, contrasting with the weaker ENSO variability in the decades before (Hoerling et al. [2004]; Huang et al. [2005]). Global mean surface temperature also experienced a trend break, transitioning from cooling in the decades prior to 1976/77 to the strong warming that characterized the remainder of the century.’ -
Quietman at 03:53 AM on 23 July 2009A Great Science Fiction Writer Passes - Goodbye Dr. Crichton
CORRECTION: "Eaters of the Dead" (dropped the "s") a.k.a. The 16th Warrior. -
Quietman at 03:51 AM on 23 July 2009A Great Science Fiction Writer Passes - Goodbye Dr. Crichton
ps "Eater of the dead" is different from most his books and IMO it's one of his best (but I like the movie better). -
Quietman at 03:48 AM on 23 July 2009A Great Science Fiction Writer Passes - Goodbye Dr. Crichton
ginckgo Dr. Crichton (M.D.) did base his novels on well research and use the worst scenarios of scientific forecasts. That is why it is called Science Fiction and not one of the other types like horror or fantasy. The alarmists are depicted as also in the worst cases but from real cases, some people are that sick enough to do something like that portrayed in "State of Fear". All of his novels are way to depict his personal fears as a message while still enjoying in a novel. To instill a reader the possibilities of what can happen if we ignore the world around us. -
chris at 03:28 AM on 23 July 2009Climate time lag
I don't think so, shawnet. Again you're ignoring the fundamental element of science which is evidence. I'm generally agreeing with the evidence-based science. You seem to be rather uninterested in this. What I'm disagreeing with is bogus arguments and misrepresentation in the two sources you have introduced to this thread (I have no problem with the Harrison work you've referred to – he seems to be doing solid science without the fatuous hyperbole of your main sources). You're happy to cheerlead for dodgy "science". Fine....but you should expect that skeptical individuals are very likely to point out its flaws. We've examined those sources and arguments in detail, in the light of 30-40 scientific papers and data resources together on this thread (i.e. not "hand-waving"). It's tedious to go through this all again, but your two sources are simply objectively deficient as science. If we consider the MWP/LIA, your Kirkby misrepresents the science on solar irradiance reconstructions, takes the misrepresented value (0.06 oC), substracts this from the LIA to mid 20th century warming (around 0.6 oC), pretends that there has been no enhanced greenhouse or volcanic contribution, and insinuates that there must have been a major CRF contribution. That's clearly bogus isn't it. We can make that conclusion objctively in the light of the science – we don't have to beat around the bush. It's not a question of agreeing or disagreeing. Now perhaps you're suggesting that while these analyses are bogus, maybe some other arguments are more convincing. Fine. Let's have a look at them. You say "the long term correlation btw CRF and climate makes no sense without some form of solar amplification.". Which long term correlation? Why, exactly, does this make "no sense without some form of solar amplification"? No one is saying that there might not be a contribution of CRF to climate. There simply isn't compelling evidence that this is of any significance whatsoever. There are lots of good scientists working on all elements of these subjects, and if evidence for a CRF-climate link of any significance arises, that will be just dandy. In the meantime let's not be suckered by tedious "catch all fill-in-the-blanks type mechanisms" that do nothing to inform our understanding. -
Thumb at 03:27 AM on 23 July 2009Climate time lag
"the sun tends to completely dominate earth climate variation historically/geologically, there is no reason this should suddenly cease in the last few centuries." "No reason?" Really? You mean no reason other than Man's contribution to atmospheric CO2 levels? I'm not sure I'm following correctly. Are you arguing that modern civilization hasn't radically altered atmospheric CO2 levels from historically/geological norms, or that CO2 isn't a greenhouse gas, or we have and it is but the sun is so dominant that it just doesn't matter? -
shawnhet at 01:52 AM on 23 July 2009Climate time lag
"I doubt that shawnet. So far when we examine in detail whatever is raised for discussion, we find that the evidence for CRF-climate links is dubious. That applies to the contemporary periods in which the relationships can be examined in detail and the periods encompassing the LIA/MWP, for which we also have a reasonably good estimate of the solar outputs. Solar influences are understandable in terms of solar irradiance changes as indicated for example by recent simulations of temperature through the last 1000 years [*]. These indicate that the lower estimates of solar irradiance reconstructions, with volcanic and greenhouse forcings, fit the hemispheric temperature data rather well. Neither is there evidence for the CRF – climate hypothesis, nor is this required to understand solar contributions over this period. Kirkby makes a pseudoscience case for a CRF contribution based on misrepresentation of the science and innuendo (he misrepresents the solar irradiance contribution and pretends that volcanic and greenhouse contributions don't exist!). I suspect if we look at Kirkby's other examples in detail we'll find these similarly deficient. " The only case were the CRF climate correlation is weak is for the short term, which I've already discussed. Your explanations of LIA/MWP are not fundamental, you don't know what causes THC to vary(if that's what's actually happening). Further, the climate is a lot more than 1000 years old. The long-term correlation btw CRF and climate makes no sense without some form of solar amplification. Frankly, it is a little silly the way you keep claiming that everyone who disagrees with you is performing bad science or pseudoscience in some way. Scientific hypotheses don't get falsified by hand-waving and name calling. BTW, even if GCMs could explain the climate changes we have observed over the past 1000 years based on lower solar forcing, they wouldn't be able to explain the extent of the correlation btw solar proxies and climate changes without such an amplification. -
Philippe Chantreau at 01:49 AM on 23 July 2009Climate time lag
So, thinga, what is the mechanism behind the diurnal temperature heat lag? -
chech1965 at 00:30 AM on 23 July 2009Greenland was green in the past
WP Vinland has been found. It's Lanse Aux Meadows on the Northern Peninsula of Newfoundland where Norse settlements were discovered in the 60s. The mistranslation of Vinland leads many like yourself to think that it means "wine" when in fact, it's a Norse word for "meadow." Which is where Lanse Aux Meadows gets its name today. Iceland was named that before they realized that naming something "Ice" land would deter settlers. Greenland was an attempt to correct that. And, thingadonta, I suggest you check out the argument "it's the sun." Fred Singer is the last person on Earth that you should be listening to when it comes to climate change. He is the same Singer that was also a "expert" when it came to the tobacco industry and proclaimed that second-hand smoke was not harmful to our health. Guess how that worked out? You should get your facts from the climate scientists, not those paid by the energy sector to be experts in the field: http://www.realclimate.org/index.php/archives/2006/11/avery-and-singer-unstoppable-hot-air/ -
David Horton at 22:15 PM on 22 July 2009Climate time lag
"They could really use this to very damaging political advantage, weakening proactive action just when it’s most needed." Well, yes, and that is precisely what is happening, on this thread and others. Swanson-Tsonis are not on the side of deniers, give you no comfort. They are simply looking at the precise nature of the period from 1998 - does it represent a stepwise upward shift, or is it simply part of the variability within error ranges, of the steady climb of GHG-induced temp rise of the last 50 years or so. So don't pretend there is some other weird and unproven mechanism lurking in there that turns the whole climate change analysis on its head and allows everybody to take bat and ball home and pretend the game never happened. Business as usual eh Yobbo, that's the name of this game is it not? And to hell with the planet. -
chris at 21:16 PM on 22 July 2009Climate time lag
re #148 "Also, be advised that there are yet other lines of evidence(that we haven't talked about yet) for CRF-climate links which detail climate fluctuations for periods when the relationship btw CRF and solar irradiance is known to be altered." I doubt that shawnet. So far when we examine in detail whatever is raised for discussion, we find that the evidence for CRF-climate links is dubious. That applies to the contemporary periods in which the relationships can be examined in detail and the periods encompassing the LIA/MWP, for which we also have a reasonably good estimate of the solar outputs. Solar influences are understandable in terms of solar irradiance changes as indicated for example by recent simulations of temperature through the last 1000 years [*]. These indicate that the lower estimates of solar irradiance reconstructions, with volcanic and greenhouse forcings, fit the hemispheric temperature data rather well. Neither is there evidence for the CRF – climate hypothesis, nor is this required to understand solar contributions over this period. Kirkby makes a pseudoscience case for a CRF contribution based on misrepresentation of the science and innuendo (he misrepresents the solar irradiance contribution and pretends that volcanic and greenhouse contributions don't exist!). I suspect if we look at Kirkby's other examples in detail we'll find these similarly deficient. "Yes, I think that if you agree that there is some form of solar amplification, we aren't that far apart. You are missing the point of the Kirkby paper, though. It is saying that the CRF-climate interaction is worth studying precisely because it appears such an unknown amplification that CRF can help fill." No. That's another illogical argument The solar effects may be amplifed by ocean current effects or may (with volcanic forcing) trigger circulation state changes. There so far isn't a requirement for internal solar amplification of the sort that you suggest. There is neither evidence for a CRF-climate link nor is there a requirement for one. Solar and volcanic forcings may well trigger or be amplified by ocean/atmosphere current effects but that has got nothing necessarily to do with any CRF effects. The evidence simply isn't there. That doesn't mean that it doesn't exist…however one can't pretend that evidence exists by misrepresenting the science and using false logic. I don't think I'm missing the point of Kirkby's review at all. He's proselytizing wildly for CRF influences, and in doing so giving a false account of the science. I don't have a particular problem with that, but if we want to understand the science we may as well recognise second-rate arguments. We are simply not going to learn anything about paleoclimate from Kirkby. Happily there's a huge wealth of good science out there. If we want to understand the difficult subject of Holocene climate variability, far better to read authoritative sources that consider the subject in its entirety. A very good source is a recent review by a large group of experts in all the relevant aspects of the subject which was published last year [**]. This review doesn't cheat the reader by pretending that the well characterised influences on Holocene climate variability don't exist! As you say the climate is complex. That complexity is represented in all its diversity in the scientific literature and in excellent reviews, such as the one by Wanner et al This is highly recommended if you feel it's worth learning about these subjects. [*] C. M. Ammann et al (2007) Solar influence on climate during the past millennium: Results from transient simulations with the NCAR Climate System Model, Proc. Natl. Acad. Sci. USA 104, 3713-3718 The potential role of solar variations in modulating recent climate has been debated for many decades and recent papers suggest that solar forcing may be less than previously believed. Because solar variability before the satellite period must be scaled from proxy data, large uncertainty exists about phase and magnitude of the forcing. We used a coupled climate system model to determine whether proxy-based irradiance series are capable of inducing climatic variations that resemble variations found in climate reconstructions, and if part of the previously estimated large range of past solar irradiance changes could be excluded. Transient simulations, covering the published range of solar irradiance estimates, were integrated from 850 AD to the present. Solar forcing as well as volcanic and anthropogenic forcing are detectable in the model results despite internal variability. The resulting climates are generally consistent with temperature reconstructions. Smaller, rather than larger, long-term trends in solar irradiance appear more plausible and produced modeled climates in better agreement with the range of Northern Hemisphere temperature proxy records both with respect to phase and magnitude. Despite the direct response of the model to solar forcing, even large solar irradiance change combined with realistic volcanic forcing over past centuries could not explain the late 20th century warming without inclusion of greenhouse gas forcing. Although solar and volcanic effects appear to dominate most of the slow climate variations within the past thousand years, the impacts of greenhouse gases have dominated since the second half of the last century. [**] Wanner H, Beer J,, Butikofer J,, Crowley TJ, Cubasch U, Fluckiger J, Goosse H, Grosjean M, Joos F, Kaplan JO, Kuttel M, Muller SA, Prentice IC, Solomina O, Stocker TF, Tarasov P, Wagner M, Widmann M. (2008) Mid- to Late Holocene climate change: an overview, Quaternary Sci. Rev. 27, 1791-1828 Abstract: The last 6000 years are of particular interest to the understanding of the Earth System because the boundary conditions of the climate system did not change dramatically (in comparison to larger glacial-interglacial changes), and because abundant, detailed regional palaeoclimatic proxy records cover this period. We use selected proxy-based reconstructions of different climate variables, together with state-of-the-art time series of natural forcings (orbital variations, solar activity variations, large tropical volcanic eruptions, land cover and greenhouse gases), underpinned by results from General Circulation Models (GCMs) and Earth System Models of Intermediate Complexity (EMICs), to establish a comprehensive explanatory framework for climate changes from the Mid-Holocene (MH) to pre-industrial time. The redistribution of solar energy, due to orbital forcing on a millennia] timescale, was the cause of a progressive southward shift of the Northern Hemisphere (NH) summer position of the Intertropical Convergence Zone (ITCZ). This was accompanied by a pronounced weakening of the monsoon systems in Africa and Asia and increasing dryness and desertification on both continents. The associated summertime cooling of the NH, combined with changing temperature gradients in the world oceans, likely led to an increasing amplitude of the El Nino Southern Oscillation (ENSO) and, possibly, increasingly negative North Atlantic Oscillation (NAO) indices up to the beginning of the last millennium. On decadal to multi-century timescales, a worldwide coincidence between solar irradiance minima, tropical volcanic eruptions and decadal to multi-century scale cooling events was not found. However, reconstructions show that widespread decadal to multi-century scale cooling events, accompanied by advances of mountain glaciers, occurred in the NH (e.g., in Scandinavia and the European Alps). This occurred namely during the Little Ice Age (LIA) between AD similar to 1350 and 1850, when the lower summer insolation in the NH, due to orbital forcing, coincided with solar activity minima and several strong tropical volcanic eruptions. The role of orbital forcing in the NH cooling, the southward ITCZ shift and the desertification of the Sahara are supported by numerous model simulations. Other simulations have suggested that the fingerprint of solar activity variations should be strongest in the tropics, but there is also evidence that changes in the ocean heat transport took place during the LIA at high northern latitudes, with possible additional implications for climates of the Southern Hemisphere (SH). -
Robbo the Yobbo at 19:11 PM on 22 July 2009Climate time lag
All I can suugest is that you take on the advice below. 'Thanks for the post Kyle. I hope you’re wrong though, because the thought of 10 more years of the deniers screaming (increasingly loudly) about how global warming is a bunch of not happening BS is a bit more than I for one can take. They could really use this to very damaging political advantage, weakening proactive action just when it’s most needed.' [Response: When the Keenlyside paper came out, Andy Revkin had a nice blog article on whether the drive for carbon mitigation action could survive (another) decadal interruption in warming. It's a good question, but one I wouldn't presume to know how to answer. Our best armory for the arguments you fear quite rightly is to build up our understanding of decadal variability and the extent to which it can cloud the long term trend. It's too soon to say whether the current "pause" in warming is anything more than statistics being clouded by one unusual El Nino event, but we should be thinking now about possible explanations just in case something more interesting is going on. --raypierre] -
Robbo the Yobbo at 18:19 PM on 22 July 2009Climate time lag
All I can suugest is that you take on the advice below. 'Thanks for the post Kyle. I hope you’re wrong though, because the thought of 10 more years of the deniers screaming (increasingly loudly) about how global warming is a bunch of not happening BS is a bit more than I for one can take. They could really use this to very damaging political advantage, weakening proactive action just when it’s most needed.' [Response: When the Keenlyside paper came out, Andy Revkin had a nice blog article on whether the drive for carbon mitigation action could survive (another) decadal interruption in warming. It's a good question, but one I wouldn't presume to know how to answer. Our best armory for the arguments you fear quite rightly is to build up our understanding of decadal variability and the extent to which it can cloud the long term trend. It's too soon to say whether the current "pause" in warming is anything more than statistics being clouded by one unusual El Nino event, but we should be thinking now about possible explanations just in case something more interesting is going on. --raypierre] -
Robbo the Yobbo at 18:08 PM on 22 July 2009Climate time lag
Oh I remember - I got to: save gaia says: 12 Jul 2009 at 5:27 pm Maybe this annomaly you speak of has something todo with the montreal protocol? http://en.m.wikipedia.org/wiki/File:Ozone_cfc_trends.png and gave up. -
Robbo the Yobbo at 18:01 PM on 22 July 2009Climate time lag
No - I gave up on the thread - it was appallingly silly. Did you read the paper? "'realclimate' are now saying T will level off over the next decade or so". Um, no, they are not. One guest paper by two academics have suggested that the well known El NIn-La Nina cycling might, in 1998 have caused an even bigger jump than predicted from CO2 alone, and that there will be a discontinuity until the effects of greenhouse essentially catch up to where they would have been anyway." Perhaps not - because the level of understanding exhibited is entirely inadequate. The paper excluded sudden climate shifts and calculated a residual warming from all other causes of 0.1 degrees centigrade/decade. To my knowledge, no one has ever claimed that temperature didn't increase in the 20th century. There may be a farmer in Woop Woop - but look at it this way - he is still as right as you. -
Robbo the Yobbo at 17:59 PM on 22 July 2009Climate time lag
No - I gave up on the thread - it was appallingly silly. Did you read the paper? "'realclimate' are now saying T will level off over the next decade or so". Um, no, they are not. One guest paper by two academics have suggested that the well known El NIn-La Nina cycling might, in 1998 have caused an even bigger jump than predicted from CO2 alone, and that there will be a discontinuity until the effects of greenhouse essentially catch up to where they would have been anyway." Perhaps not - because the level of understanding exhibited is entirely inadequate. The paper excluded sudden climate shifts and calculated a residual warming from all other causes of 0.1 degrees centigrade/decade. To my knowledge, no one has ever claimed that temperature didn't increase in the 20th century. There may be a farmer in Woop Woop - but look at it this way - he is still as right as you. -
David Horton at 16:58 PM on 22 July 2009Climate time lag
Which part of "superimposed upon an overall warming presumably due to increasing greenhouse gasses" did you not understand? And yes, I did read the guest blog, written, as you know, by Kyle Swanson, as a summary and explanation of the Swanson-Tsonis paper. And the thread. Did you? -
Robbo the Yobbo at 16:35 PM on 22 July 2009Climate time lag
I was obviously optimistic to think that people would read the paper before rejecting it. It's OK David, just read the 'guest blog' and the posts - it won't challenge your preconceptions. -
Robbo the Yobbo at 16:20 PM on 22 July 2009Climate time lag
Sorry - is it the squid that are getting bigger because of global warming or the sheep that are getting smaller? Must be all that CO2 snow. I think the Swanson and Tsonis paper says that the recent rate of warming (between 1977 and 1997) is 0.1 degrees centigrade per decade from all other causes when the points of rapid climate shift are excluded – and that there will be no warming trend for the next decade or so. I made no other argument – simply that in my value judgement, 0.1 of warming between 1977 and 1997 from whatever cause, and there are many, is insufficient justification for continued global warming silliness. The 50 year modulation of ENSO is involved but so are modes of major climate variability. The Swanson and Tsonis paper uses coupled climate parameters - ENSO, the Pacific Decadal Oscillation, the North Atlantic Oscillation, and the North Pacific Index – and postulates that when these modes of major climate variability resonate, or are ‘synchonised’, the ‘character of ENSO variability’ is changed for 2 or 3 decades with a break in the ‘the global mean temperature trend’. They say that clouds may be involved. Acknowledging the limited cloud data available from the ISCCP – it is a possibility for the latest climate shift in 2001/2002. Swanson and Tsonis are recognising an underlying physical reality. The ‘modes of climate variability’ are real, quantified and, as I say, not simply the 2 to 7 year ENSO variation. ‘Extension of this analysis to the entire 20th century as shown in the bottom panel of Figure 1 reveals three climate shifts marked by breaks in the temperature trend with respect to time, superimposed upon an overall warming presumably due to increasing greenhouse gasses. Global mean temperature decreased prior to World War I, increased during the 1920s and 1930s, decreased from the 1940s to 1976/77, and as noted above increased from that point to the end of the century. Insofar as the global mean temperature is controlled by the net top-of-the-atmosphere radiative budget [IPCC 2007], such breaks in temperature trends imply discontinuities in that budget. Such discontinuities are difficult to reconcile with the presumed smooth evolution of anthropogenic greenhouse gas and aerosol radiative forcing with respect to time [Hansen et al. 2005]. This suggests that an internal reorganization of the climate system may underlie such shifts [Zhang et al. 2007]. And ‘However, the nature of these past shifts in climate state suggests the possibility of near constant temperature lasting a decade or more into the future must at least be entertained. The apparent lack of a proximate cause behind the halt in warming post 2001/02 challenges our understanding of the climate system, specifically the physical reasoning and causal links between longer time-scale modes of internal climate variability and the impact of such modes upon global temperature.’ I take it you will entertain the idea, reject it and accuse me of being psychologically aberrant. You might try these for a little background – I suggest that you take your time because real understanding comes from a considered and balanced approach. http://www.aoml.noaa.gov/phod/docs/ETPacInterdecadal.pdf http://climate.gi.alaska.edu/researchprojects/pages/AKpaper10.html -
David Horton at 16:10 PM on 22 July 2009Climate time lag
#159 Look thingy, that kind of stuff goes down well in talk back radio, or on the letters page of "The Australian", or at a branch meeting of the National Party, but your in the wrong venue here. "not even examine solar effects and solar heat lag" - two different things, as you must know. Solar effects (and I assume you are including Milankovitch cycles here) are well known, taken seriously, included in all models, account for some climatic changes in the past and present. never any dispute about that, much as you might try to mislead people. "Solar heat lag" as an explanation of current warming is, on the other hand, nonsense. John's original post points this out, and a number of us have responded on this thread. But I'll bet you keep saying it and keep writing it endlessly into the future, each time pretending it is a new idea never considered, Nobel Prize winning research. "'realclimate' are now saying T will level off over the next decade or so". Um, no, they are not. One guest paper by two academics have suggested that the well known El NIn-La Nina cycling might, in 1998 have caused an even bigger jump than predicted from CO2 alone, and that there will be a discontinuity until the effects of greenhouse essentially catch up to where they would have been anyway. It's just a hypothesis, considering the very big jump in 1998. I don't think it's correct, nor do many of the posters on the very long thread that follows (read that have you, thought about it?), but in any case it has absolutely no bearing, as the authors say, on the inevitable CO2 induced warming. To pretend that it does (or that warming has somehow stopped in the last decade) is denialist dishonesty of the most obvious kind. You might say it is "discouraging rational inquiry". And a concern for the future of the planet (last time I looked, the only one for miles around suitable for my grandchildren to live on) is a "greenie rant"? So be it. -
thingadonta at 15:59 PM on 22 July 2009Climate time lag
"That people like you or thinga with his obsession on transposing the diurnal "heat lag" to a larger scale would try to give lessons in assessing the science is, well, ironic". Transposing scale in natural systems is very common-eg from atomic to mesoscopic (eg crystal structure), eg fractal geometry, eg diurnal to annual, annual to decadal, and so on. In my field we use the term 'bonzai'-when comparing features of the very small to the very large. It is a very common scientific practice. But of course my field isn't strictly 'climate science', so it isn't relevant... There are numerous examples of scale correlations, and lag effects in nature, so I don't know what bee is in your bonnet about it, but one of the reasons I bring lag effects up is because some academics/ideologists tend to hate/miss the idea of a lag effect, because they can't directly 'match' causes and effects, which means they can't easily reduce innate variation down to their preferred mantra. It is the same reason historically that various ideologists tended to hate the idea of Einsteins relativity when it came out -it produces a mismatch between ideology, causes-effects, and general perspective. -
thingadonta at 15:40 PM on 22 July 2009Climate time lag
re150: Ideology attempts to place everything within the same set of related ideas and reduce inherant uncertainty, chaos and variation; it always takes the same side where there is fundamental ambiguity, and it usually suits vested interests-call them banks, academics, greens or whatever. Another feature of ideology is over-confidence, another suppression of valid dissent etc etc. To not even examine solar effects and solar heat lag on the 'energy imbalance' in Hansen 2005 reveals an ideological stance. Or even better, an 'ideological imbalance'. You could argue that I have a solar ideological bent, but with good reason, the sun tends to completely dominate earth climate variation historically/geologically, there is no reason this should suddenly cease in the last few centuries. Your c02 and general greenie-rant is a good example of an ideological stance. Pity you can't see it, but that's the nature of extreme ideology-it denies its own existance, or in Dawkins words-the ideology/meme complex secures its own perpuation by discouraging rational inquiry. But getting back to the topic, because the earth is not warming quite fast enough, 'realclimate' are now saying T will level off over the next decade or so. (Perhaps they have secretly taken a look at the sun lately-like KGB agents secretly trying to figure out why the capitalist system works so well). -
Philippe Chantreau at 14:22 PM on 22 July 2009Climate time lag
Boy that Yobbo is a horse that can talk. And that carbonic snow cone, you'll have it chocolate or vanilla? LOL. Oh, I forget, it's so darn cold in Vostok. That people like you or thinga with his obsession on transposing the diurnal "heat lag" to a larger scale would try to give lessons in assessing the science is, well, ironic. -
David Horton at 14:02 PM on 22 July 2009Climate time lag
#151 Silly me, so it's the CO2 ideology that says you can burn all of the carbon sequestered underground for millions of years and pump all that extra CO2 into the air while having no effect on the climate, while minor changes, up and down, in the sun, and which, conveniently, we can do nothing about, account for whatever climate change we have seen in the last 50 years. Oh and you might want to re-read the RC paper on "warming interrupted", and the discussion which follows. It doesn't say what you think it says, and in any case you do know it's an hypothesis and has nothing to do with solar variation, don't you? You did read the sentence "it’s important to note that we are not talking about global cooling, just a pause in warming" didn't you? You do know that this is just a variation on the already well known effect of El NIno-La NIna variation on the long term rise and rise in emissions-caused general global warming, don't you? I certainly wouldn't call you an egghead. -
Robbo the Yobbo at 13:15 PM on 22 July 2009Climate time lag
Pseudo egghead? I resent the implication that I'm not a real egghead. You really should spend some time on the science before leaping into the fray. The realclimate dicussion is here: http://www.realclimate.org/index.php/archives/2009/07/warminginterrupted-much-ado-about-natural-variability/ And the Swanson and Tsonis paper is here. http://www.uwm.edu/~kswanson/publications/2008GL037022_all.pdf -
Robbo the Yobbo at 13:11 PM on 22 July 2009Climate time lag
Pseudo egghead? I resent the implication that I'm not a real egghead. You really should spend some time on the science before leaping into the fray. The realclimate dicussion is here: http://www.realclimate.org/index.php/archives/2009/07/warminginterrupted-much-ado-about-natural-variability/ And the Swanson and Tsonis paper is here. http://www.uwm.edu/~kswanson/publications/2008GL037022_all.pdf -
Lee Grable at 13:06 PM on 22 July 2009Climate time lag
It's actually 9:00 PM on July 21st. I know, non relevant. -
Lee Grable at 12:33 PM on 22 July 2009Climate time lag
Get a life for crying out loud!!!! -
Lee Grable at 12:30 PM on 22 July 2009Climate time lag
When I first came across his website, I was excited. "Finally, I've found someplace that really examined the "skeptic arguement", I.E,the tactics they used to maintain the illusion of a debate. What I ended up finding was a place where a bunch of psuedo eggheads congregate to impress themselves and each other with how smart they sound. What a waste of cyberspace! -
Robbo the Yobbo at 12:28 PM on 22 July 2009Climate time lag
I think it might be the ideology of ocean acidification is 10 times worse than calculated, the ideology of an ice free Arctic by 2010, the ideology of 7m sea level rise by the end of the century, the ideology of a few pairs of breeding humans surviving in Antarctica by 2100. It is an ideology that not even a failure of the oceans to continue to warm (at a minimum) and falling surface temperatures cannot dent. It is the ideology that argues that the planet is still warming. It is an ideology that prefers GISSTEMP over HADCRU because GISSTEMP includes some marginal arctic stations but refuses to countenance the independent UAH or RSS satellite methods because they are showing less warming. It is an ideology that says that any exaggeration is responsible if it scares people into acting, any action is moral if it advances the cause and any opposition is evil and corrupt. This is an ideology that fails to recognise obvious 50 year climate cycles in global temperature, fisheries, sea surface temperature, Arctic temperature, rainfall, North American temperature etc. Not even last week’s effort on realclimate can put a dent in their confidence. Let me repeat the message of realclimate – no warming trend for 20 to 30 years (i.e. a 25 year cooling phase) from 2001/2002 and a background warming of 0.1 degree C/decade from all other factors. We are in a cooling trend and it will continue for a decade or 2 more. There is a trend of temperature increase of bugger all (an Australian technical term) in the UAH globally and depth average lower troposphere temperature. A value judgement – a trend of 0.10C/decade in temperature rature is insufficient to justify all of the present silliness and outright perverse self righteousness of Co2 ideology. -
David Horton at 10:15 AM on 22 July 2009Climate time lag
#147 - well, there's a new one "CO2 ideology". I wonder what that could be? Is it the ideology that shows, from physical principles, that CO2 is a greenhouse gas: or could it be the ideology that shows CO2 levels increasing? Or the ideology that shows, from the isotope signature, that the increase comes from human use of fossil fuels? Or perhaps the chemistry ideology that shows increasing ocean acidity as usual buffering effect of the oceans starts to be overwhelmed by the speed of increase in CO2? Or could it be the ecological ideology that finds rapid changes in the behaviour and distributions of animal and plant species? Or the ice ideology that measures the reduction in glacier lengths and ice cap volumes? So much ideology, so little science eh? Or am I thinking of the opposition? -
Lee Grable at 02:36 AM on 22 July 2009Climate time lag
This is just like the huffpost, except with bigger, fancier words. -
shawnhet at 01:51 AM on 22 July 2009Climate time lag
Chris: ""Phenomena do not typically have long-term with one another when there is not some causal connection" But we've already seen that this simply isn't true for the very phenomenon we've been discussing. A large set of analyses described in my post #71 indicates that any correlation between CRF and climate-related influences (low level clouds) is NOT causal, and is an artefact of the correlation of the CRF with the solar cycle, components of which DO correlate with the effect." The fact is that at best, the only thing that has been disproved is *one particular interaction of CRF* with climate. Further, as I have already mentioned, climate science is very complex, and what appears true today is not necessarily so(adjustments to climate data are pretty common). Finally, there is no inherent reason why short term "weather" fluctuations might not obscure a CRF signal, that might become clearer over the long-term. Fundamentally, what is clear is that there must be some sort of solar amplification to climate, and we don't know what it is yet. Also, be advised that there are yet other lines of evidence(that we haven't talked about yet) for CRF-climate links which detail climate fluctuations for periods when the relationship btw CRF and solar irradiance is known to be altered. "I'm happy to leave it there until evidence accrues that allows us to make more detailed causal interpretations of Holocene N. hemisphere climate variability. I have no problem with accepting uncertainty where this exists - what we certainly don't do is to introduce Kirkby-style "catch all fill-in-the-blanks type mechanisms" to "fill in" uncertainty, particularly when the causality associated with the mechanism is increasingly found to be suspect." Yes, I think that if you agree that there is some form of solar amplification, we aren't that far apart. You are missing the point of the Kirkby paper, though. It is saying that the CRF-climate interaction is worth studying precisely because it appears such an unknown amplification that CRF can help fill. Cheers, :) -
thingadonta at 22:52 PM on 21 July 2009Climate time lag
re: 144 David Horton This is a quote from the press release from Hansen himself, about Hansens et al's 2005 paper on the so-called energy imbalance: "the climate system is now being pushed so hard that I have suggested that we can say with confidence that 2005 will have a warmth comparable to that of 1998, and the remarkable 1998 global temperature record will soon be broken, if not this year than within the next several years.)," (http://junkscience.com/Greenhouse/imbalance_release.pdf) Note: the years from and including 2005 were not 'record breakers'. Also, ocean T has flattened or cooled since the early 2000s. His 'energy imbalance', supposedly driven by c02, is just not working. The cause(s) of the 'energy imbalance' in the paper of Hansen et al 2005,(if the 'energy imbalance' is indeed real-which it may not be), NEVER took into account the possibility that oceans have been heating from 1955-1998 in line with a solar heat lag effect from the solar peak in the 20th century, he simply assumes ocean heat is being driven by c02/greenhouse gases. He checks this with 'models', no models have been run regarding solar heat lag, clouds etc. However, it could equally be a confirmation of the solar heat lag one would expect from the mid 20th century-that is- there seems to be nothing 'driving' the heat in the oceans when modelled with the energy (apparently) leaving the atmosphere. Hansen et al 2005 never even investigate or consider thispossibility, because they are so bound up with c02 modelling and ideology. The years since this paper, 2005, have also invalidated his alarmist predictions above, and if the solar heat lag alternative theory is correct (or a version of it), there is no '0.6C warming left in the pipeline', since the sun is now waning, as is T. -
thingadonta at 22:47 PM on 21 July 2009Climate time lag
re: 144 David Horton This is a quote from the press release from Hansen himself, about Hansens et al's 2005 paper on the so-called energy imbalance: "the climate system is now being pushed so hard that I have suggested that we can say with confidence that 2005 will have a warmth comparable to that of 1998, and the remarkable 1998 global temperature record will soon be broken, if not this year than within the next several years.)," (http://junkscience.com/Greenhouse/imbalance_release.pdf) Note: the years from and including 2005 were not 'record breakers'. Also, ocean T has flattened or cooled since the early 2000s. His 'energy imbalance', supposedly driven by c02, is just not working. The cause(s) of the 'energy imbalance' in the paper of Hansen et al 2005,(if the 'energy imbalance' is indeed real-which it may not be), NEVER took into account the possibility that oceans have been heating from 1955-1998 in line with a solar heat lag effect from the solar peak in the 20th century, he simply assumes ocean heat is being driven by c02/greenhouse gases. He checks this with 'models', no models have been run regarding solar heat lag, clouds etc. However, it could equally be a confirmation of the solar heat lag one would expect from the mid 20th century-that is- there seems to be nothing 'driving' the heat in the oceans when modelled with the energy (apparently) leaving the atmosphere. Hansen et al 2005 never even investigate or consider thispossibility, because they are so bound up with c02 modelling and ideology. The years since this paper, 2005, have also invalidated his alarmist predictions above, and if the solar heat lag alternative theory is correct (or a version of it), there is no '0.6C warming left in the pipeline', since the sun is now waning, as is T. -
thingadonta at 22:06 PM on 21 July 2009Climate time lag
re: 144 David Horton This is a quote from the press release from Hansen himself, about Hansens et al's 2005 paper on the so-called energy imbalance: "the climate system is now being pushed so hard that I have suggested that we can say with confidence that 2005 will have a warmth comparable to that of 1998, and the remarkable 1998 global temperature record will soon be broken, if not this year than within the next several years.)," (http://junkscience.com/Greenhouse/imbalance_release.pdf) Note: the years from and including 2005 were not 'record breakers'. Also, ocean T has flattened or cooled since the early 2000s. His 'energy imbalance', supposedly driven by c02, is just not working. The cause(s) of the 'energy imbalance' in the paper of Hansen et al 2005,(if the 'energy imbalance' is indeed real-which it may not be), NEVER took into account the possibility that oceans have been heating from 1955-1998 in line with a solar heat lag effect from the solar peak in the 20th century, he simply assumes ocean heat is being driven by c02/greenhouse gases. He checks this with 'models', no models have been run regarding solar heat lag, clouds etc. However, it could equally be a confirmation of the solar heat lag one would expect from the mid 20th century-that is- there seems to be nothing 'driving' the heat in the oceans when modelled with the energy (apparently) leaving the atmosphere. Hansen et al 2005 never even investigate or consider thispossibility, because they are so bound up with c02 modelling and ideology. The years since this paper, 2005, have also invalidated his alarmist predictions above, and if the solar heat lag alternative theory is correct (or a version of it), there is no '0.6C warming left in the pipeline', since the sun is now waning, as is T. -
David Horton at 21:32 PM on 21 July 2009Climate time lag
John - time you stepped in again. Your attempt to set the record straight (so to speak) on "heat lag" has made the heat lag obsessives even more so. It is a theory that can't be falsified, because you simply choose whichever time lag will allow a close match with your non-cause. -
thingadonta at 17:14 PM on 21 July 2009Climate time lag
Things (so far) that a solar heat lag of ~40-60 years explains: -the so called "energy imbalance" of Hansen 2005-ie why the oceans have heated up to the early 2000s, in apparent imbalance with air T and heat flux(Hansen et al don't bother examining solar heat lag to explain this ocean warming 1955-1998). -ocean heat flat-lining since the early 2000s. (ie: its after 2:30pm on any average day now) -air T flat lining since early 2000s (same as above) -flattening sea levels in last few years -increasing T since ~1980, despite no apparent increase in solar activity (heat lag effect) -sun slowly waning yet no marked decrease in T yet, only flat-lining (heat lag effect) -inability of c02 theorists to recognise heat lag effect since one can't easily match immediate causes and effects (which academics are generally trained to do). -possibly delayed low cloud cover after solar peak is reached, excaberting T in late 20th Century, particularly in temperate zones with less low cloud cover (closer to condensation point, and cosmic rays). -not examined or even thought of by Gore, Hansen and co because doesnt fit c02 ideology. Prediction: T flat lines and then wanes from early 2000s-2020+, as opposed to Hansen's 2005 prediction of "record breaking years" within 3-4 years after 2005 by his so called 'energy imbalance' (already invalidated)-which is just a solar heat lag effect. -
Robbo the Yobbo at 16:49 PM on 21 July 2009Climate time lag
There is an amount of energy called the enthalpy of fusion. In the ice/liquid phase transition – the energy from the atmosphere or ocean used to melt ice is internalised as kinetic energy. This energy is ‘hidden’ but it is not sufficient to make a huge difference to global energy budgets. Melting ice may cause oceans to be cooler – just like the ice in your glass. Ocean temperature is measured but the calculated heat content of the ocean is the important metric. Just like the total heat in an insulated container containing ice and water doesn’t change rapidly – although the enthalpy of fusion may be significant on that scale. The total heat content of the planet doesn’t change as a result of melting ice other than with the minor enthalpy change noted. It is no great mystery why the ocean is not warming at the anticipated rate – or while the atmosphere is cooling at the same time. http://bbso.njit.edu/Research/EarthShine/literature/Palle_etal_2008_JGR.pdf There has been a decrease in shortwave forcing since 1998 of 2 W/m2. Earth albedo was at a minimum in 1998 and has increased since. Both low level and high level cloud decreased to 1998 and increased thereafter in the climatically important equatorial zone. I am inclined to accept the Usoskin’s correlation of cosmogenic isotopes – over 1150 years. A correlation against global and hemispheric reconstructions of temperature. I am inclined to accept as plausible the mooted mechanisms of a cosmic radiation cloud connection. The experiment evidence in the SKY experiment is intriguing. I am inclined to think that there is a correlation of the aa geomagnetic index with 20th century temperature as below. The question is – is the cloud response characteristic of 20 to 30 year climate cycles found everywhere in the climate record? Not enough cloud data. But the cycles remain – adding to temperatures in the warming phase of 1976 to 1998 and masking warming since. In the current cool phase - there appears to be a cloud connection. The regularity of phase changes suggests that we are looking for a cyclic phenomenon. http://academicjournals.org/ijps/PDF/Pdf2006/Oct/El-Borie%20and%20Al-Thoyaib.pdf Can we use the aa geomagnetic activity index to predict partially the variability in global mean temperatures? M.A. El-Borie1 and S.S. Al-Thoyaib2 1 Physics Department, Faculty of Science, Alexandria University, Alexandria, Egypt. 2 Physics Department, Al- Rass Teacher’s College, Al-Qaseem, K.S.A. Accepted 17 October, 2006. Data for geomagnetic activity index aa and solar sunspot number Rz for 1868-2004 were subjected to correlation analysis with the global surface temperature (GST). The annual-means GT show that it had two warming phases and one cooling period. Observations of the Earth's near-surface temperature showed a global-mean temperature increase of approximately 1.1° C since 1877, occurred from 1887 to 1940 and from 1970 to the 1998. The temperature change over the past 35 years (1970-2004) is unlikely to be entirely due to internal climate variability. Attribution of the warming early in the century has proved more elusive. The correlation analysis between the variation of global temperature and both aa geomagnetics and solar activity are +0.5 ± 0.05, for any lag or lead, indicating a significant role in such variation. All graphs have illustrated strong correlations between the solar activity and geomagnetics and surface global temperature. Our results do not, by any means, rule out the existence of important links between solar activity and terrestrial climate. Our results displayed that the present changes in aa geomagnetics may reflect partially some future changes in the global surface temperatures. Key words: Geomagnetic induction, Atmospheric sciences, Climatology, Climate and interannual variability. -
thingadonta at 11:58 AM on 21 July 2009Climate time lag
#130 - "Now that the oceans T appear to be flattening and cooling since early 2000s " How many cubic miles of land ice are running into the oceans as ice-cold water in recent years? Has this number been increasing? Wouldn't this have some effect on ocean temps in the same way adding ice to your drink will cool your drink. No this doesnt work with the volumes involved. If you warm a cup of water with ice in it, the ice melts but does not cool the water overall, as the water is also warming when you warm the cup. The ice can only cool the water if there is a very large ice/water differential with poor heat transfer, which is not the case here-there is a large ocean/ice differential. The oceans are cooling because the sun is now waning. c02 has no effect on ocean T. -
chris at 09:27 AM on 21 July 2009Climate time lag
"Phenomena do not typically have long-term with one another when there is not some causal connection" But we've already seen that this simply isn't true for the very phenomenon we've been discussing. A large set of analyses described in my post #71 indicates that any correlation between CRF and climate-related influences (low level clouds) is NOT causal, and is an artefact of the correlation of the CRF with the solar cycle, components of which DO correlate with the effect. That could hardly be plainer. We don't choose the "simplest theory possible" if the theory is incompatible with the evidence. We know that the CRF generally varies in line with solar outputs (whether or not there is a strict linear relationship) and in very many studies is used as a proxy for solar output variation. We can hardly assert that changes in solar irradiance are insufficient to account for the phenomenon observed if we don't (a) have a measure of the solar irradiance contemporaneous with the phenomenon of interest and (b) have a good handle on the magnitude of solar irradiance required to influence the phenomenon. I don't see any point in introducing "catch all fill-in-the-blanks type mechanisms" as pseudo-explanations (CRF) when the evidence doesn't support these. What we do have is abundant evidence that ocean/atmosphere circulation changes are associated with much of the variation in high Northern latitude climate variation through the Holocene. We can accept that (heat transfer variations) as a fundamental proximate cause of temperature proxies observed since the evidence is very strong. We don't have to postulate global scale phenomena since the evidence doesn't support this. We don't understand the ultimate causes of the circulation changes very well- these do seem to have a solar component for Bond cycles observed in the Northern latitudes. The evidence indicates that this isn't due to the CRF component of the solar influence. Where we do have some evidence (MWP/LIA) this is likely solar irradiance/volcanic sea surface temperature influences (see Trouet et al, 2009 cited above, for example). I'm happy to leave it there until evidence accrues that allows us to make more detailed causal interpretations of Holocene N. hemisphere climate variability. I have no problem with accepting uncertainty where this exists - what we certainly don't do is to introduce Kirkby-style "catch all fill-in-the-blanks type mechanisms" to "fill in" uncertainty, particularly when the causality associated with the mechanism is increasingly found to be suspect. -
shawnhet at 08:50 AM on 21 July 2009Climate time lag
Chris: "That's a self-contradictory assertion. It contradicts the essential basis of scientific understanding namely . We've already seen that there is abundant evidence for THC contributions (Lund et al, 2006; Denton and Broecker, 2008; Trouet et al, 2009; see Thornalley et al 2009 below) to the events we've been discussing; we could cite much more of this. You reject it without giving any evidence." My point is that saying that THC changes are responsible for something when we don't know what causes the THC to change is simply begging the question. I think THC is a symptom of climate "fundamentals", not properly the cause of them. For you to simply accept that the THC causes climate change without understanding what causes the THC is not "supporting fundamental interpretations". ""I don't know enough about the Bond effects to consider causality in detail, but I'd be very interested to see what scientific analysis informs your views on this. In the meantime, I'm prepared to accept Bond's interpretation of solar forcing with some potenial THC amplification. Since we don't know the magnitude of solar irradiance contemporaneous with these events we can hardly assert that this was not sufficient to mediate these phenomena. Your either this/either that binary choice is non-scientific, since it pre-selects for interpretations that are not necessarily consistent with the evidence. For example, it's quite possible that the Bond events report changes in heat transport through variations in thermohaline circulation that predominantly affect the high Northern latitudes. That's consistent with much of the science I've already cited (including Bond et al 2001) as well as additional recent evidence for Holocene oscillations in North Atlantic heat and salinity driven by variations in the THC [*], and observations that the events observed in the High Northern latitudes (Bond events, MWP; LIA) generally don't have deep Southern Hemisphere correlates [**] " First off, if THC is the result of an amplification of some sort then THC-forcing is simply an indirect solar forcing. Secondly, the large climate events correlate to CRF, so if the magnitude of CRF doesn't correlate with the magnitude of irradiance, then that is good evidence that CRF *on its own* has climate impact. You call this either-or science, I call it simple logic. Phenomena do not typically have long-term with one another when there is not some causal connection. I think it is always preferable to have the simplest theory possible. Cheers, :) -
chris at 08:26 AM on 21 July 2009Climate time lag
whoops, I left out a word: My first two sentences should read: That's a self-contradictory assertion. It contradicts the essential basis of scientific understanding evidence. -
chris at 08:22 AM on 21 July 2009Climate time lag
"I don't really want to get into the reasons why THC based explanations aren't very good IMO. That is a whole other line of argument. I don't really have a fundamental problem with them as *response* to long-term solar heating, I suppose. It is simply with them as a catch all fill-in-the-blanks type mechanism, I object to." That's a self-contradictory assertion. It contradicts the essential basis of scientific understanding namely -
shawnhet at 06:05 AM on 21 July 2009Climate time lag
What Bond et al. are rather clear on is the correlation btw solar events and climate ones and the magnitudes thereof. They don't mention CRF, of course, (and I never said they did), but they do say such things as "Our correlations are evidence, therefore, that over the last 12,000 years virtually every centennial time scale increase in drift ice documented in our North Atlantic records was tied to a distinct interval of variable and, overall, reduced solar output." They provide various possible amplifiers for solar input, because solar input alone doesn't work. Obviously, CRF climate interactions are one possible solar amplifier. "Think about it. Your assertion requires that you know the magnitiude of the irradiance changes contemporaneous with the events. We've been talking about contributions from irradiance changes (0.2 oC's worth) during a period where there's a reliable reconstruction (Lean et al back to the Maunder Minimum). Do you know what the irradiance values were further back in the Holocene? I don't think so…" There are two options here. Either the magnitude of solar irradiance has a (more or less) constant relationship to the level of CRF fluctuations or it does not. If the first case is true, then the pattern of climate fluctuations to the solar proxies implies that there is an amplifying agent, which is why Bond et al. proposes some. If, OTOH, the magnitude of solar changes is not constant wrt CRF changes then there is no reason why the correlations that Bond et al find should exist at all. IAC, perhaps we are making headway here - do you agree with Bond et al. that some sort of solar amplification is likely? I don't think we have enough evidence to tell what the nature of the solar amplification is, but we do IMO have enough to tell us that one does exist. I don't really want to get into the reasons why THC based explanations aren't very good IMO. That is a whole other line of argument. I don't really have a fundamental problem with them as *response* to long-term solar heating, I suppose. It is simply with them as a catch all fill-in-the-blanks type mechanism, I object to. Cheers, :) -
chris at 04:56 AM on 21 July 2009Climate time lag
I've read Bond et al shawnet. I was referring to some research published in the intervening period based on research that isn't nearly 10 years old. Your idea that research fields can be fully defined by recourse to single papers or dodgy reviews is not going to give you much insight into these difficult subjects! Note that you've mis-interpreted Bond et al who are rather consistent with the evidence from the pukka science that I've been discussing, and makes no mention of any CRF effects. In fact Bond et al interpret their data in terms of solar irradiance changes, amplified by thermohaline circulation effects:"Each of those episodes also corresponds to paired intervals of reduced solar irradiance and increases in North Atlantic ice drift in our records" and: "Results of recent atmospheric general circulation (GCM) modeling, however, have shown that a decrease of only ~0.1% in solar activity over the 11-year sunspot cycle could produce a change in surface climate through the atmosphere's dynamic response to changes in stratospheric ozone and temperature"
Whereas you consider the thermohaline circulation "pretty speculative" (even 'though I provided papers referring directly to evidence for this for the periods specified), Bond et al certainly don't consider it to be speculative:The Arctic-Nordic Seas thus may have been a key region where solar-induced atmospheric changes were amplified and transmitted globally through their impact on sea ice and North Atlantic thermohaline overturning. Reduced northward heat transport, moreover, could have further altered North Atlantic latitudinal temperature and hydrologic gradients, potentially enhancing the climate response in low-latitude climates [e.g., (39)].
This assertion of yours is illogical: "Do you know of a minor change that would cause a 2C change in the Atlantic ocean. Certainly, it couldn't be solar which can only change irradiance by about 0.2C or so". Think about it. Your assertion requires that you know the magnitiude of the irradiance changes contemporaneous with the events. We've been talking about contributions from irradiance changes (0.2 oC's worth) during a period where there's a reliable reconstruction (Lean et al back to the Maunder Minimum). Do you know what the irradiance values were further back in the Holocene? I don't think so… -
Thumb at 04:26 AM on 21 July 2009Climate time lag
#130 - "Now that the oceans T appear to be flattening and cooling since early 2000s " How many cubic miles of land ice are running into the oceans as ice-cold water in recent years? Has this number been increasing? Wouldn't this have some effect on ocean temps in the same way adding ice to your drink will cool your drink? -
shawnhet at 04:17 AM on 21 July 2009Climate time lag
Chris:"That's not to say that there isn't also a lot of evidence over very long periods for N. hemisphere – S. hemisphere "see-saw" with compensating temperature rises and falls, or at least hemispherically-dominant phenomena. That's partly the theme of the Denton/Broecker paper in my post #116. For example the Dansgaard-Oeschger events that indicate large periodic temperature fluctuations in the Greenland cores are barely represented in Antarctic cores, and these are also interpreted in terms of exactly the same ocean/atmosphere heat transfer varaibility that likely underlie much of the MWP/LIA temperature variation. It's just that the D/O events entailed far more dramatic heat transfer changes possibly involving complete shutdown and later on rapid resumption of the thermohaline circulation in the N Atlantic." The thermohaline explanation is pretty speculative frankly, but IAC, the point is that the see-saw doesn't operate symmetrically on both sides of the equator. The Northern side fluctuates much more than the Southern side(and the Southern side doesn't really go up, when the Northern side goes down). ""I'm not going to comment on Bond events (other than in relation to D/O events for which Bond events might be a Holocene-scale minor continuation). I don't know enough about these and haven't got time to do much hunting in the scientific literature (last Thurs to Sat I was ill at home and found lots of time to do this – as well as watching the Open, the Ashes and the Tour de France!). If you know of any scientific literature that provides a good account of these phenomena as well as a discussion of potential causality I'd be more than happy to read these…" Bond events aren't minor. Do you know of a minor change that would cause a 2C change in the Atlantic ocean. Certainly, it couldn't be solar which can only change irradiance by about 0.2C or so. In that context, the correlation btw such changes and CRF makes no sense. IAC, good luck with your search. Let me know what you find out when you have explored other avenues of evidence. Here is a pretty good place to start IMO - Bond, G.C., B. Kromer, J. Beer, R. Muscheler, M.N. Evans, W. Showers, S. Hoffmann, R. Lotti- Bond, I. Hajdas and G. Bonani, Persistent solar influence on North Atlantic climate during the Holocene, Science 294, 2130–2136 (2001). Cheers, :)
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