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Rapid Descent

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About Rapid Descent

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  1. Thanks for the thoughtful and cordial reply. For the 800 year lag, early estimates were made by Fisher et al in 1999, who arrived at 600+/-400: Lag estimated by Fisher Then subsequently by Caillon et al, who used 40Ar isotopes to estimate 800+/-200: Lag estimated by Caillon Although the recent increase in CO2 is unquestionably from the burning of fossil fuels, it is worth noting that a massive amount of CO2 is exchanged between the atmosphere and various natural sources and sinks every year. The first guess is that the glaciation (or deglaciation) associated with the sharp change in temperatures influences this equilibrium. But it is only a guess; based on limited proxy evidence. Much more information is needed to fully understand what it going on, and that will take a long time to accumulate.
  2. You might want to look at that graph a little more closely. Firstly, it is CO2 and temperature plotted againsts time, not CO2 vs temp as you say. I think whitemice's interpretation on position is rather more accurate than your own. Generally, temp rise happens first, CO2 changes very soon after. There are a couple of cases where CO2 seems to move first, but around a dozen where the temp changes first. I believe a quantitative analysis of this yields CO2 lagging temperature by around 800 years. But then... as I said, people tend to see what they want to see in proxy data.
  3. You are joking - aren't you? Do you seriously think there is any credible claim that climate responds linearly to CO2 at 10ppm/deg C? How, exactly, do you think that mere ocean changes are going to offset the 400 degrees C that such a climate sensitivity would have introduced? Climate naturally varies at all timescales - it exhibits self-similar behaviour just as you would expect a complex, coupled, non-linear system to. Attempts by you and others to attribute specific, linear reasons for these shifts is amusing, but is a question of fitting evidence to proxy data. As I made clear above, you can fit several quite opposite conclusions into the Vostok ice core data. (Thanks for demonstrating that, BTW). (my emphasis) - I note you say "It has been postulated" - so what? Incidentally, it has also been "postulated" that shutting off the thermohaline circulation would make essentially no temperature difference whatsoever in NW Europe (citing geographical relationships as the primary cause for the mild NW European climate). Again, so what? You can postulate all you like about what may or may not happen in a complex, coupled non-linear system, but your answers won't be much better than rolling a die.
  4. Whitemice, If one were to believe that CO2 was driving temperature in these graphs, rather than the temperature driving CO2, you come to the conclusion that the climate "sensitivity" is around 10ppm / deg C. If you assume (like someone did in an earlier thread) that everything behaves linearly, you would conclude that this greenhouse effect would cause a greenhouse effect in the Ordovician period (when CO2 levels were at around 4400ppm) of some 400 degrees. Even if you assume a log relationship, you still get an effect of the order of 100 degrees. This is patently absurd, even if you take into account reduced insolation of the period and different continental layout, there is nothing that could offset this enormous effect. (Also, during the Ordovician, massive glaciation activity took place, and the world entered an ice age... irrespective of the high CO2 content of the atmosphere) The more logical conclusion is that the temperature is most likely influencing the carbon cycle, which is a far more credible explanation for the ice core data. Edited to note: of course, this ties in with your observation that CO2 changes appear to lag temperature. Caveats apply: all of this is open to interpretation, as these are proxy measurements, and you can almost always make a case for the opposite conclusion. Occam's razor should apply here. It isn't necessarily the truth, but the best reasonable conclusion we can draw.
  5. My post makes it clear that I disagree with the approach Monckton takes (although I agree with him on a number of sub-points, which are supported by primary scientific evidence, e.g. there are serious statistical flaws with some of the millenial scale temperature reconstructions) I would agree nobody disputes that the surface and air temperature (particularly of the Northern Hemisphere) has warmed in the last thirty years or so when averaged on annual to decadal scales. There is much dispute on whether it is the warmest going back 800,000 years because it is not possible to assign credible confidence intervals to data going back much beyond 400 years. For example, the Vostock ice core (most commonly quoted on the scales you are referring to) has century-scale averaging (i.e., decadal trends won't even show) and unknown uncertainty to be applied to the graph (so open to intepretation). However, there is much dispute as to the exact cause of the recent warming. Science simply isn't sufficiently advanced to attribute cause, unless you make the gross oversimplification that the climate behaves in a simple, linear manner. Many scientists dispute this (I've referenced some of the more eminent ones in a previous post, and can dig them back out if required)
  6. Nice "conspiracy" straw man. Works well with your "fossil fuel lobby" appeal-to-motive fallacy. And why reference the press? Why not try science? (And by science, I mean primary sources, rather than selective secondary sources, such as the Royal Society, or third-hand-twice-removed sources, such as the media) FWIW I don't agree with Chris Monckton's analysis for various reasons (primarily because it makes the same mistakes as mainstream climate science, assuming the climate system can be trivially separated into linear, distributive components like forcing and feedbacks) and he makes a number of other errors (Chinese in the arctic in 1421? Really?) but his observations on flaws of the "hockey stick" temperature curve are spot on (and derived from a primary scientific source). BTW Viscount Monckton has a great interest in maths and scientific analysis (he is the creator of the "eternity" puzzle) No conspiracy necessary: just entrenched bias. Plenty of scientific evidence to counter the AGW scare stories. Much debate about this. The differential between London and places at similar latitudes on the east coast of Canada are often cited as "proof" that the thermohaline circulation warms the north western portion of Europe (including the UK), but in fact there is much research to support the fact that local geography and wind patterns do far more to shape these weather patterns than the ocean currents. Furthermore, predictions as to the consequences of increased warming are split; some argue that warming will increase the thermohaline circulation. But, it makes a good scare story (like most of the others). That's what the science says: my personal view is that predicting the future of the north atlantic overturning current is akin to guesswork (which could explain the diverse claims in the scientific literature). Of course the only stories we tend to hear about are the extreme ones (because that is what people love to hear)
  7. Interesting! The Royal Society (which appears to be a political player in this piece, sad to say) references the IPCC TAR (Third Assessment Report) which quotes the conclusion "Furthermore, the increase in surface temperature during the 20th century in the Northern Hemisphere was likely (a chance of 66 to 90%) to have been greater than for any other century for the last 1000 years." If you do some digging, you find that the report the IPCC relied on for this conclusion was... the very "hockey stick" graph Chris Monckton refers to; the very one which contains the statistical errors. But don't just take the "fossil fuel lobby"'s word for it, criticisms have appeared in the peer-reviewed literature (details below) "Hockey sticks, principal components, and spurious significance", McIntyre and McKitrick, Geophysical Research Letters Please note this is not on the website of a "fossil fuel lobby" promoter, but in the same peer-reviewed journal that the original 1000-year hockey stick article appeared. The American academy of sciences subsequently investigated the results and concluded that it was incorrect to assign confidence intervals (e.g. the 66% to 90% chance) to any claims associated with temperatures prior to the 17th century, as no independent assessment is possible due to the lack of available data. So both the IPCC TAR and the Royal Society report quoted above are in error. The IPCC TAR has the excuse that it was published before the errors in the graph were found. What is the excuse of the Royal Society for still having out-of-date scientific information on their website?
  8. Geek man, I see you still haven't given any substantive responses to my questions regarding non-linear dynamics on the other thread. You say we don't need to "tweak" our description of climate. Yet no climate model successfully predicted the recent massive loss of heat energy from the sea. Given the enormous amount of energy lost over the last couple of years (of the order 3x10^22 joules), wouldn't you say our understanding of climate needs a little more than a "tweak"? Ref. Lyman, J. M., J. K. Willis, and G. C. Johnson (2006), Recent cooling of the upper ocean, Geophys. Res. Lett., 33, L18604, doi:10.1029/2006GL027033. Link
  9. Austin Allegro, I think your view here is very astute. Science and politics do not make good bedfellows. When science adopts a viewpoint that has some political expediancy associated with it, objectivity goes out of the window. Trofim Lysenko was a great example of this. (Please note: I am not attempting to draw direct parallels between climate science and Lysenkoism, just drawing attention to the broader topic of science and politics interacting) I've already promoted Prof Pielke Sr so I may as well mention his son (Prof Pielke Jr no less!) as well... who does very good work on the interaction of science and politics. He has a blog here which often has sharp and insightful views on the interactions of science and policy, and it is quite well written and accessible to the non-scientist. He also has expertise on hurricanes and hurricane damages. I would agree with this also. There are very good reasons for diversifying energy provision, including energy security, preserving natural resources, air quality, etc. They way in which that is achieved is influenced by the reasons for which you choose to act; a knee-jerk reaction to a global warming scare is not (IMHO) the right reason. Adren, just to warn you, some of those sites I pointed you to at the end are very detailed technical websites. Following some of the detailed papers can be a bit like swimming through treacle, lots of heavy duty stats and analysis - and very few sound-bite answers. From your earlier comments it sounds like you would be quite capable of following it, just depends on how much of your time you want to devote to it! I personally find it a fascinating subject, but I appreciate not everyone sees the technical detail in that same light!
  10. Adren, I'm not such a fan of the Monckton approach - to me, it is fighting fire with fire, Chris Monckton's work is guilty of trivialising the complex relationships of climate and cherry-picking of data. The climate scientist who most closely shares my view, I think, is Professor Roger Pielke Sr, whose article on climate as an initial-value problem I referenced above. He has a website here and a weblog here, and I find them very useful resources. I'd also recommend some of the work carried out by Professor Demetris Koutsoyiannis, website and links here, who has done some excellent work in terms of analysing complex, coupled non-linear systems, and some of the issues with to do with behaviour over different scales and very long term persistence in natural systems.
  11. Geekman, Your response is surprisingly unscientific. Can you please point to where I said we should give up modelling the climate altogether? I don't remember making such a statement, and I share no such opinion. However I do believe we should recognise the limits of what modelling can provide. I concur entirely with Adren that modelling is an excellent route to finding out what the limits of our understanding are - forming hypotheses which can then form the basis of experiments to learn more about the climate. Models are valuable scientific tools, but they are being used in ways that are quite inappropriate by the climate science community. My statement regarding causality is purely related to the ice cores, which relate to thousands of years ago, not the last 50 years of direct measurements as you describe above. Please try to follow my arguments and stop twisting them into something I did not say. I warned in my post against confusing hard measurements with the problems of interpreting proxy data. I also have not made any statement about CO2 emission policies, yet you imply a particular view. It is not the role of scientists to insist on particular solutions, that is the role of politicians. If you want to know what my political view is, just go ahead and ask, don't try and guess it. But please bear in mind I am more interested in the science than the politics. I also realised that you misunderstood my complaint about the linearisation of climate. It is not just about implying a trivial linear relationship between CO2 and temperature (which, as I point out, basic physics does not support, whether or not your preferred proxy measurement indicates a correlation over a limited extent). My criticism is that much recent works implies a linear relationship for the entire system, i.e., the various forcings and feedbacks exhibit the properties of distributivity etc., and can be trivially separated into individual components. If you look at the Lorenz attractor (since you bring him up), the individual terms of the integrals required to compute the trajectory of the attractor are simple terms, yet they combine in a manner that you would never predict were you to see each term in isolation. I have some respect for Lovelock due to his openness and honesty - he welcomes debate and discussion and is one of the few in the field who openly admits to engaging in the global cooling scare in the 1970s - but please don't confuse his view of "Gaia" with science. The Gaia premise is founded on a statistical error. In his book, he argues that the probability that a planet should support life in the way earth has is exceptionally unlikely, and therefore rules out a Darwinian style view (we only have one planet, so it cannot have "evolved"). His error is a trivial one - he should have applied conditional probability. His question should have been, "given that intelligent life has evolved on a planet, what is the probability that the intelligent lifeform should observe that planet is capable of supporting life?". I think he would find the probability startlingly close to one.
  12. In terms of op-eds, this is probably a more significant piece: Chaotic world of climate truth Partly because Mike Hulme is no sceptic of human-induced climate change, he very much buys in to the "consensus", yet even he is disturbed by some of the extreme language used - primarily by the media and NGOs, but increasingly by politicians and scientists who realise it can help get them noticed. As I said earlier, it is a sorry state of affairs and I personally think history will record this issue as a low ebb in scientific objectivity.
  13. Thanks for the thoughtful reply. As ever, in science disagreement should be seen as an opportunity (combined experiments to resolve / understand the differences) but all too often it is the cause for entrenchment of position and isolation. To back up my views, I would reference the reader to Roger Pielke Sr.'s detailed note on climate as an initial-value problem, which can be found on the web here, and the Mandelbrot paper referenced above (unaware of a version of that paper on the internet unfortunately). This provides both a theoretical basis and observational evidence to support my views.
  14. This is exactly the problem with climate science. This is a clear ad hom / guilt by association fallacy. It is a political instrument, not a scientific one. For the record: I believe evolution is an excellent model for the origins of life and species, whereas creationism is weak and unconvincing I believe that the moon landings were not faked I believe that the towers were knocked down by terrorists not as a US conspiracy .. yet I also believe there are serious flaws in the way climate science is addressing the issues, and also how they interact with politics and the media. So I don't seem to fit into your model. I'm happy to quote my qualifications but that would be meaningless as I'm not willing to make my identity known (preventing verification of my claims) because as soon as anyone admits to being a climate sceptic they put themselves at risk of character assassination by environmental groups. What way is that to conduct scientific debate?
  15. Global temperature, in particular, cannot be meaningfully represented by one parameter. In two- or three-dimensional models (e.g. GCMs), they are represented by a more complex relationship. If modelled on a 5 degree x 5 degree basis with three cuts through in altitude, you have 7,776 parameters defining temperature alone. CO2 is simpler because it is well-mixed but can still has considerable seasonal variation in some parts of the world (e.g. Europe). Plenty of scope for elephants. Basic physics tells us this is not so, if you isolate the relationship between CO2 and temperature you find an approximately logarithmic relationship, i.e. for each doubling of CO2 concentration you get a linear increment in temperature. Whilst this may be crudely approximated to a linear relationship from the limited extent measured in the ice cores, extrapolating this is itself flawed, and ignoring the other interactions even more so. The d18O isotope measurements contain a lot of data, but those data are open to interpretation... never confuse proxy data with reliable instrumented readings, which is where we lack good quality data. For example, with the relationship between CO2 and temperature from the ice cores, there is a serious debate about causality (amongst other things). If the earth behaved like a black body in a shell of gas with the only variable property being CO2, this much would be true. But add in other interactions and that doesn't follow unless you assume the entire system is linear, which is highly unlikely. This is only true if the system is not self similar on multiple scales (natural variability proportional to 1/f). This was my earlier point and tests for self-similar behaviour have been conducted by people like Mandelbrot (reference below), who provides solid evidence for this. In this case, to truly detect the difference in two systems (one with fixed CO2, one with increasing CO2) may take millions of years to detect (if detectable from mean global temperature at all). Reference "Global dependence in geophysical records", Mandelbrot and Wallis, 1969. Water Resources Research 5 pp 321-340
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