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All IPCC definitions taken from Climate Change 2007: The Physical Science Basis. Working Group I Contribution to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change, Annex I, Glossary, pp. 941-954. Cambridge University Press.

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Comments 107751 to 107800:

  1. An underwater hockey stick
    johnd wrote : "With regards to the previous original reference to the JAMSTEC discussion, I provided the full link so that anyone interested could have full access to the entire discussion, as you so obviously had done, I therefore could not have been accused of being selective or cherry picking parts of the discussion to suit." johnd, I have replied to this on the 'How reliable are climate models ?' thread.
  2. Models are unreliable
    johnd wrote (on another thread) : "With regards to the previous original reference to the JAMSTEC discussion, I provided the full link so that anyone interested could have full access to the entire discussion, as you so obviously had done, I therefore could not have been accused of being selective or cherry picking parts of the discussion to suit." Unless the particular comment of yours, to which you are referring, has been deleted, I cannot see where you have provided that link. All I can see from you is this from your post which contained the actual quote : His details are at http://cawcr.gov.au/bmrc/clfor/cfstaff/hhendon.htm As far as I am aware, the link to the actual email discussion was provided by doug_bostrom. That is why I replied in the ways (here and here) I did.
  3. The value of coherence in science
    Is there a way to clasify how incoherent a set of arguments are ? A sort of Mohs scale for invalid arguments. And perhaps there could be a simple visual representation of how certain websites are self contradictory ? Also, would be better to refer to Climate Skeptics (as in 'denialists') as Climate Incoherents .
    Response: We have a database of "contradiction pairs" - pairs of skeptic arguments that contradict each other. One thing I noticed about them was some pairs were more in conflict than others. I welcome any suggestions on how to rate the degree of contradiction :-)
  4. The value of coherence in science
    The Inconvenient Skeptic's site is illuminating - in that it reveals how the mythological conspiracy theory that sustains the anti-AGW industry has grown up. Two crucial paragraphs: The science of global warming, it says is "a flawed theoretical idea, even from the beginning. Unfortunately it was 80 years before it could fully be proven as incorrect and as a result the flawed idea had plenty of time to become well entrenched in the scientific community." ['Fully proven' in this case means eyeballing a non-attributed graph that bears no relationship to any actual temperature data from any reputable source.] In the many decades since Arrhenius, the site claims, the only physicists who have challenged this (mythical) orthodoxy have been ignored "much like the real science continues to be ignored today." It then sets the records straight: "If there were no CO2 in the atmosphere at all, the earth would be ever so slightly cooler, but barely enough to notice. Once there is about 50 ppm in the atmosphere, any additional amounts do not matter." The confidence with which such assertions are made is what lies behind the credibility that sites like this enjoy in the Anglo-Saxon world among laymen of a certain political disposition.
  5. Anne van der Bom at 19:10 PM on 6 October 2010
    Climate Cherry Pickers: Falling sea levels in 2010
    I just can't resist to comment. My favourite Steve 'Pixelcounter' Goddard piece is his declaring Hansen's Antarctic ice predictions a failure based on recent trends. On closer examination the Hansen prediction in question appears to be for equilibrium at 2x CO2, i.o.w. somewhere around 2070. We're now in 2010. The completely uncritical reception of this story at WUWT is jaw dropping and very revealing.
  6. What constitutes 'safe' global warming?
    HR @47 "Truely basic thermodynamics? No assumptions about forcings and feedbacks are involved in these sorts of calculations?" At the most fundamental level, yes. Just about all the forcings and feedbacks net out to some energy flux imbalance for the planet. This energy imbalance results in a net change in Total Heat Content for the climate system of which the Oceans are far and away the dominant element, but with a long time delay. Since the oceans have such huge thermal mass they take much longer to reach a new temperature than the atmosphere. And once the difference in temperature change of the oceans vs the atmosphere grows, this difference starts to alter the energy flows between atmosphere and ocean, retarding the temperature change in the atmosphere until the oceans catch up. And note, in this argument I haven't said warming. The reasoning is exactly the same whether the energy imbalance is positive - warming, or negative - cooling. The atmosphere leads, the oceans follow more slowly, the disparity between the two then retards the atmosphere until the oceans have caught up before a final equilibrium has been achieved. Basic Thermodynamics. What is more complex, and the subject of discussion is what all the forcings and feedbacks add up to and how this balance might evolve over time. But the same basic principle would apply if the Sun suddenly changed its Heat output by 1%, or if we started using geoengineering to add aerosols to the air. Note that I have only made this argument in qualitative terms. What the quantitative analysis is I leave to someone way above my pay grade. But if the atmospheric temperature change to date is positive, then the 'in the pipe line' warming MUST also be positive unless some process suddenly reverses the net forcing. Basic Thermodynamics. As to the quantitative estimate of how much, my get feel says that 0.6 is too low. But I am not qualifed to make that quantitave estimate. The analysis of the experts probably trumps 'my gut' Consider, of the heat changes measured so far, around 90% has accumulated in the oceans and only 3% in the atmosphere. But the the upper levels of the ocean have only seen temperature change of a fraction of the change in the atmosphere so far, and the abyssal oceans virtually not at all. To use another analogy, imagine a tribe of meerkats trying to move an elephant. As all the meerkats chatter around, pushing and shoving, there is some net direction in which they are trying to move the elephant. Even so, it takes some time for them all to move the elephant anywhere. And the Oceans are the elephant of the climate system.
  7. Carbon Dioxide - Everyone's Favorite Pollutant
    KR #98 That is the most perceptive remark on this thread. The fact that ozone in one place is "pollution" (i.e., harmful), and in another not only beneficial, but pretty much vital to life on Earth. To what degree this is actually true for CO2 is literally "up in the air". :) As with freon, the next question, is the EPA going to ban Coca-Cola?
  8. What constitutes 'safe' global warming?
    44.Glenn Tamblyn Truely basic thermodynamics? No assumptions about forcings and feedbacks are involved in these sorts of calculations?
  9. What constitutes 'safe' global warming?
    #40 scaddenp Another favorite paper on this website, murphy et al 2009, seems to to balance the energy budget without resorting to "missing heat". This suggests an inconsistency between Hansen 2005 and Murphy 2009. A new paper in press from Knox and Douglass suggests Hansen has got it wrong, questioning the TOA measurements. I realise that this part of the paper is very brief but the comment comes about from the fact that their finding seem to be moving in an opposite direction to what Hansen would like to see. And in a roundabout way this new paper on indirect aerosol forcing, Ruckstuhl et al 2010, which if accurate suggest IA forcing may be around 0 rather than -0.7W m2 assumed by the IPCC. Given this large potential error then my guess is the assumptions behind Hansen (and others) calculations need to be constantly re-assessed. (I'm happy to here how I've mis-interpreted these papers)
  10. The value of coherence in science
    thingadonta, your argument about economics is sort of irrelevant to this particular issue in science and coherence versus incoherence. The big difference with the coherent science and the incoherent opposing arguments is the *strength* of the scientific coherence. The calculations about CO2 in climate science are entirely consistent with the calculations about CO2 used in lasers. It doesn't matter that these calculations are done within models you don't like. If they were done in pen and ink on parchment by 100,000 mathematicians in cubicles, they'd still have that irreducible core of coherence with the physics used in laser technology and any number of fields I couldn't pronounce the names of, far less spell. Disprove climate science? Go right ahead. The first thing you have to do is prove that it is *possible* for CO2 to have different radiative properties in atmosphere compared to exactly the same molecules in a laser. Once that's done, I'll leave you or your team of Nobel Prize winners to come up with the next step.
  11. The value of coherence in science
    No doubt, thingadonta. Why not get it over with all at once and give mathematics a good stirring? Who cares whether or not multiplying and dividing from different directions gets us to the same place? As the fellow said, "A foolish consistency is the hobgoblin of little minds..." If we're orbiting satellites and they're not quite behaving correctly, there's absolutely no reason why people doing orbital mechanics and other people researching mascons should care if their findings agree, it simply doesn't matter. Oh, wait, I just noticed. No matter how hard I frown, regardless of whether I buy or do not buy "white goods," Big G stays the same. Oops.
  12. The value of coherence in science
    The stockmarket is no more coherent than people. It is a social phenomenon. The basis of science is not a social phenomenon. > non-verifiable theories Please read Empirical evidence that humans are causing global warming and comment there.
  13. The value of coherence in science
    @thingadonta: "I suppose you would also say the stockmarket would only be correct, or useful, or practical, if it was coherant." Why would anyone say that? You're comparing a chaotic transactional system with argumentation about a scientific theory. You're not just comparing apples and oranges, here, but apples and screwdrivers. By the way, the field of Economics dates from the 18th century. I fail to see how getting "coherance" (sic) out of it could have taken "several thousands of years." I'm puzzled by what you're trying to say. Are you arguing in favor of incoherence?
  14. The value of coherence in science
    thingo #11 So what you're saying is that one of the assumptions surrounding economics is that it doesn't have to make sense, and consequently the same should be true of science. There's a reason that economics is called the "dismal science". Alternatively there's the old joke: Why did god invent economists? To make weathermen look good. With respect to the stock market, it tracks money, which is an abstract construct created by humans. It's reality is internally generated (which is why insanities like refusing to price externalities exist in that field). Natural sciences on the other hand exist to explain phenomena that usually have some sort of existence outisde of human concerns. As a result, your argument makes no sense whatsoever to me.
  15. The value of coherence in science
    I suppose you would also say the stockmarket would only be correct, or useful, or practical, if it was coherant. It took several thousand years to get this nonsense about 'coherance' out of economics, and I suppose it's goung to take several thousand years to get this nonsense about 'coherance' out of fields of science which deal with projections and non-verifiable theories.
  16. The value of coherence in science
    TIC, Sigh. You say " I am told that CO2 is the main forcing factor in climate," You are getting confused between the relative contributions of different forcing mechanisms, and the time scale involved. Moreover, you seem to be confusing different eras and forcing mechanisms, and also seem to misunderstand the importance of rate of change. For some time now, anthro GHGs have been a significant forcing mechanism (they are of course not the only forcing mechanism, that is why the global temperature has not been increasing monotonically), and that forcing will increase continue to increase with time anthro CO2 and other GHGs concentrations continue to rise (not to mention increases in GHGs from feedbacks as the permafrost melts, for example). You also fail to propose a physical and realistic natural mechanism which explains the the recent warming. Not only that, but one which explains the distribution of the warming around the globe (i.e., polar amplification), timing of warming (i.e., evening temperatures warming faster than day-time temperatures and most pronounced warming in winter), as well as the vertical profile of warming (warming of troposphere and cooling of stratosphere). Now there is a well-established and tested coherent theory which can explain all that, and it is not natural..... Many of the misconceptions and myths surrounding anthropogenic climate change are addressed elsewhere on this site. I really do recommend you read them and the literature cited therein. Let us cut to the chase, because this is what it ultimately boils down to, and this is where the uncertainty lies: 1) What do you understand equilibrium climate sensitivity to be without feed backs for doubling CO2 (or CO2 equivalent)? 2) What do you understand equilibrium climate sensitivity to be with feed backs (positive and negative) for doubling CO2 (or CO2 equivalent)? Thanks.
  17. The value of coherence in science
    Bringing back the discussion to this podcast (still can't find the RSS feed to subscribe to the podcast), I think the topic of coherence is essential to repeat often. Someone doesn't have to be an expert to understand that incoherent explanations have problems.
  18. Climate Change: Past, Present, and Future
    GC, why don't you contact Alley himself at Penn State? The Yooper
  19. The value of coherence in science
    Re: The Inconvenient Skeptic (1, 3) I looked at your Taylor Dome link. What I see is a graph with trend lines fitted...with no real analysis, no discussion of the radiative physics involved; in short, no evidence that you possess a substantive understanding of what you are trying to debunk. Climate Science is an extremely complex subject. Unless you have a multi-disciplinarian background, playing with data sets to create graphs reveals no insights into the underlying processes involved due to the lack of context and understanding. For example, your statement: "The Taylor Dome shows 4 warming periods comparable to the current." is rebutted by a layman's discussion here. I second everything archiesteel said in his most excellent comments above (except for #6). ;) You really should try to gain a greater understanding of the role of CO2 as the Biggest Control Knob. The Yooper
  20. Uncertain Times at the Royal Society?
    As well, it's worth remembering that the Nobel Peace Prize is not really intended in the same way as a Nobel for physics, or chemistry: “The said interest shall be divided into five equal parts, which shall be apportioned as follows: /- - -/ one part to the person who shall have made the most important discovery or invention within the field of physics ...” versus “The said interest shall be divided into five equal parts, which shall be apportioned as follows: /- - -/ one part to the person who shall have done the most or the best work for fraternity between nations, the abolition or reduction of standing armies and for the holding and promotion of peace congresses.” as the categories are somewhat weirdly presented at the Nobel Prize website.
  21. bgood2creation at 15:43 PM on 6 October 2010
    CO2 effect is saturated
    A few of your links are not working, but I think I found them. Griggs 2004 http://rose.bris.ac.uk/dspace/bitstream/1983/999/1/paper.pdf Philipona 2004 http://www.agu.org/journals/ABS/2004/2003GL018765.shtml However, I could not find the Chen 2007 article. And thanks for the informative article. Blessings,
    Response: I've updated the links (and tracked down Chen 2007). Many thanks for the URLs - let's hope they stay active for as long as possible :-)
  22. The value of coherence in science
    TIS, you may want to have a look at this to get a sense of proportions with regards to temperatures during the last millennium.
  23. Uncertain Times at the Royal Society?
    Although he's much-decorated I don't see anything about a Richard Lindzen Nobel prize in his bio: Richard Lindzen He does seem to have that reputation in some circles. Perhaps this was the shared award for IPCC work? Pretty ironic if so. I notice that the sites referring to him primarily as a Nobel laureate don't mention why he received his award. In any case, other than He Who Shall Not Be Named, no individuals were apparently included in the 2007 Nobel accorded to the IPCC: The Nobel Peace Prize 2007 was awarded jointly to Intergovernmental Panel on Climate Change (IPCC) and Albert Arnold (Al) Gore Jr. "for their efforts to build up and disseminate greater knowledge about man-made climate change, and to lay the foundations for the measures that are needed to counteract such change"
  24. The value of coherence in science
    @TIS: "The natural increase was a 9% increase. Since then there has been a 39% increase in CO2. That is a multiple of 4.3 not 3 orders of magnitude. 280ppm to 390 ppm is in no way an increase of 1000x." A 9 percent increase over millenia, which amounts to a rate of increase of 0.27ppm per century (the figure from the graph on your blog) , vs. a rate of increase of 2ppm per year, which is likely to increase to 3 and more if the current trend in emmissions continues. As I said, about three orders of magnitude. "I was not insulting although the article was to those that disagree. I don't mind being insulted" Uh...who said anything about insults? I didn't insult you, nor did I insinuated you insulted others. I simply asked you to stop spamming your blog. "but please look at the Taylor Dome temperature of the past 1,000 years before saying that the current warming is very unlikely to be natural. The Taylor Dome shows 4 warming periods comparable to the current." It's hard to say because your graph does not show how it compares to the instrumental record. Without providing the context of temperatures for the last hundred years, your claim is meaningless. In other words, your graph does not allow to make the claim that similar average temperature increases have occured in the last 1,000 years, nor that average temperatures have been higher than the current ones during the past millenium. You should learn more about the science before adding one more outlet to an already crowded contrarian blogosphere...
  25. The value of coherence in science
    TIS at 1, Why are you using the extreme ends of the Earth - Arctic on your website, and Antarctic in your link - to make an argument about average global temperatures? Surely a dataset with a decent spread of locations across the globe would be far more suitable?
  26. New observations find underwater Arctic Shelf is perforated and venting methane
    Some interesting recent developments on the methane clathrate/PETM front. 1. From GEOLOGY (Abstract only available):
    "Changes in ocean circulation have been proposed as a trigger mechanism for the large coupled climate and carbon cycle perturbations at the Paleocene-Eocene Thermal Maximum (PETM, ca. 55 Ma). An abrupt warming of oceanic intermediate waters could have initiated the thermal destabilization of sediment-hosted methane gas hydrates and potentially triggered sediment slumps and slides. In an ensemble of fully coupled atmosphere-ocean general circulation model (AOGCM) simulations of the late Paleocene and early Eocene, we identify such a circulation-driven enhanced intermediate-water warming. Critically, we find an approximate twofold amplification of Atlantic intermediate-water warming when CO2 levels are doubled from 2× to 4× preindustrial CO2 compared to when they are doubled from 1× to 2×. This warming is largely focused on the equatorial and South Atlantic and is driven by a significant reduction in deep-water formation from the Southern Ocean. This scenario is consistent with altered PETM circulation patterns inferred from benthic carbon isotope data and the intensity of deep-sea carbonate dissolution in the South Atlantic. The linkage between intermediate-water warming and gas hydrate destabilization could provide an important feedback in the establishment of peak PETM warmth."
    Source: CO2-driven ocean circulation changes as an amplifier of Paleocene-Eocene thermal maximum hydrate destabilization 2. From Philosophical Transactions Of The Royal Society A (Abstract only available):
    "The plausible range of carbon mass input, approximately 4000–7000 PgC, strongly suggests a major alternative source of carbon in addition to any contribution from methane hydrates. We find that the potential range of PETM atmospheric pCO2 increase, combined with proxy estimates of the PETM temperature anomaly, does not necessarily imply climate sensitivities beyond the range of state-of-the-art climate models."
    Source: A Palaeogene perspective on climate sensitivity and methane hydrate instability 3. From a poster presentation at the EGU, 2010
    "Hyperthermal climate events are geologically brief (~10-100kyrs) transient periods of marked global warming associated with prominent negative carbon isotope excursions and deep-sea carbonate dissolution. They are most likely the result of massive injections of isotopically light carbon into the ocean-atmosphere system. One plausible source of isotopically light carbon is a widespread dissociation of continental slope, sediment-hosted methane gas hydrates. Proposed triggers for the dissociation of such deep-water hydrates include a pronounced (~4ºC) warming of intermediate to deep waters driven by changes in global overturning circulation (Dickens et al., 1995). The most prominent hyperthermal event of the Ceonzoic is the Paleocene Eocene thermal maximum (~55Ma; PETM)." "CONCLUSIONS We show modelling results which support the hypothesis that Eocene hyperthermals could be paced by orbital variations. The mechanism for this forcing is orbitally induced switches in ocean circulation, which lead to non-linear intermediate ocean warming, with the possibility of resulting destabilization of methane gas hydrates. The switches in circulation are associated with high eccentricity and obliquity and maximum seasonality in the Northern Hemisphere."
    Poster Source: Is There An Orbital Control On Eocene Hyperthermals? Apologies for no links to the full articles (both paywalled). I've requested the articles through my employer library; will offer up a deeper dish when I get them. The Yooper
  27. The Inconvenient Skeptic at 15:18 PM on 6 October 2010
    The value of coherence in science
    The natural increase was a 9% increase. Since then there has been a 39% increase in CO2. That is a multiple of 4.3 not 3 orders of magnitude. 280ppm to 390 ppm is in no way an increase of 1000x. I was not insulting although the article was to those that disagree. I don't mind being insulted, but please look at the Taylor Dome temperature of the past 1,000 years before saying that the current warming is very unlikely to be natural. The Taylor Dome shows 4 warming periods comparable to the current.
  28. Climate Change: Past, Present, and Future
    GC - it takes time for air in accumulating snow to become isolated from atmosphere which is why ice core is no help to you for past 100 years. Dont splice the instrument record on (though this shows you are misinformed about Mann) - just put current central greenland average temperature onto the graph - see that graphic - higher than any time is last 3000 years.
  29. The value of coherence in science
    @TIS: There's nothing incoherent with CO2 rising by a relatively small amount and temperatures in slow decline. The reason is that CO2 is one of the main forcings but not the only one. What this means is that, since the Holocene Climate Optimum, the slow rise in CO2 has not been enough to counter the other long-term forcings (Milankovitch cycles in this case, IIRC). What you don't seem to understand is that the CO2 increase you refer to is *three* orders of magnitude smaller (i.e. about 1000x less) than the current increase. As for the temperature drop, it is also dwarfed by the current increase, representing only 2.5% of it in absolute terms. The Earth does go through cycles, short and long, but what you have to realize is that it's highly unlikely the current warming is due to a natural cycle. In fact, considering what the science tells us, it's nearly impossible. Oh, one more thing: you should really quit spamming links to your blog. It's not a very classy move.
  30. Uncertain Times at the Royal Society?
    Lindzen got a Nobel? News to me though he most certainly has produced outstanding work. Lindzen and Choi not being one them however. It has been specifically rebutted in the published literature and so far as I am aware, Lindzen has not responded. Furthermore, observational data would appear to directly refute it.
  31. gallopingcamel at 14:53 PM on 6 October 2010
    Climate Change: Past, Present, and Future
    scaddenp, (#80), Alley's interest was the Younger Dryas. I am hoping someone at NCDC has looked carefully at the last 2,000 years and how to fill in the interval since 1905. Is there an instrumental record that can be "spliced on"? That is one of the things that got Michael Mann into trouble! The snow accumulation issue is a tough one, especially if the flow rates are as strongly affected by thickness as Alley claims (8th power?).
  32. The Inconvenient Skeptic at 14:51 PM on 6 October 2010
    The value of coherence in science
    You are correct that coherence is important. It is not incoherent to say that the Earth goes through short cycle and long cycle changes. The Earth is experiencing a short cycle of warming during a long cycle of cooling. The data supports that statement. You argue about not knowing the price of sheep, but wanting to buy while they are cheap. I pointed out that the Taylor Dome shows the past 6,000 years cooling while having 10,000 of increasing CO2 levels. I am told that CO2 is the main forcing factor in climate, but not to concern myself with the data. That is incoherent. There are many incoherent people that are skeptics. There are many incoherent people that believe in AGW. I will be called incoherent for not believing in AGW, but in the end CO2 has been rising for the past 10,000 years and the Earth has been in a long term cooling trend for the past 6,000 years. The Earth is not a linear system and as such there are many peaks and valleys along the way. The current period is a peak, I hope it lasts a long time because the valleys are unpleasant. The Earth is always changing. It has never and will never stay the same. Our current technology is allowing to see and measure that change. John Kehr The Inconvenient Skeptic
  33. gallopingcamel at 14:38 PM on 6 October 2010
    Uncertain Times at the Royal Society?
    scaddenp (#117)' I will probably be told to take this issue to another thread but you did ask a fair question. Lindzen & Choi 2009 is a paper on the feedback question written by a Nobel laureate. The Lindzen paper is controversial but so are the dozen models cited by the IPCC.
  34. Extreme weather isn't caused by global warming
    Scaddenp, bearing in mind that I'm assuredly -not- being smart-aleck, in some ways this site is "open source" in the sense that people drag in all sorts of literature and deposit it for everybody's enjoyment. "Enjoyment" often takes the form of attacking offerings and dragging them back and forth like meat thrown to a pack of feral dogs, but that's just one possible outcome. If you should have a few minutes to spend beavering away at Google Scholar, looking for likely candidates, you can bet that what you find will be most appreciated.
  35. What constitutes 'safe' global warming?
    Matthew @43. Agnostic @42 referred to CO2e, not CO2. Currently CO2e is at around 430-440 ppm. And you are right, CO2 is growing at about 2 ppm/yr at present. During the 2000's, CO2 emissions were growing at about 3%/year. That is a doubling time of 25 years. So if sustained, by 2035 we would be growing at 4ppm per year and 8 ppm per year by 2070. That growth rate however is made up of different contributions from different parts of the world. And the biggest growth rate is China. During the 2000's their coal consumption grew by around 7%/year, which is a doubling period of around 10 years. And as they continue to grow, their increasing size means their growth rate will come to have a bigger impact on the global growth rate figure. How long before we see 4 or 5% global growth rates. 5% growth is a doubling of around 15 years so by 2025, that would be increases of 4ppm/year and 8 ppm/year by 2040. So if China (and other nations like India following them) are able to sustain their economic growth rates for several decades to come and can't bring renewables / nuclear onstream at major scales incredibly fast, we could blow through the doubling level of 560ppm before mid century. Bringing renewables to mainstream generation levels that fast is a herculean task. And if we allow that much fossil fuel capacity to be built, decommissioning it before the end of its working life will involve capital right-offs that will make the WFC look like chickenfeed. And if the growth stalls in those countries, then the political, social and military implications of that are terrifying. We are in deep sh!t, right here, right now, today. Humanity may pay a terrible price for the fact that deep down, we just don't 'get' the Compound Interest Law!
  36. Uncertain Times at the Royal Society?
    GC - a published paper demonstrating net negative feedback would be more convincing. Any of these nobel laureates got one out? Net negative feedback would mean sensitivity of less that about 1.9. By contrast, we have all these papers measuring or modelling sensitivity by various means which show it higher. And for a longer view, Wally estimated the temperature for 2010 with surprising accuracy (all right he was lucky), in 1975 with an estimate of 2.8 (thats strongly positive feedback) though he also overestimated our emissions by a bit.
  37. Extreme weather isn't caused by global warming
    This rebuttal lack links to actual studies which is unusual and I think should be fixed.
  38. gallopingcamel at 13:28 PM on 6 October 2010
    Uncertain Times at the Royal Society?
    Baz(#111), If it turns out that rising CO2 is a major contributor to the recent upturn in temperatures we should be able to get a good estimate of "feedbacks". Are they negative or positive? There are plenty of people on this site who are convinced that the feedbacks are strongly positive but many well respected scientists (some of them with Nobel prizes) disagree. Sadly the question is well above my pay grade so I waiting to see what happens next.
  39. What constitutes 'safe' global warming?
    HumanityRules @39 "No disrespect but I do find it funny the casual way you drop in the " 0.6°C warming in the pipeline" as if it's a concrete fact." The actual figure of 0.6 is an estimate. That there must be an outstanding warming of some level that is still 'in the pipeline' is basic thermodynamics. The oceans have warmed less than th air since they have massively greater thermal mass. It takes time for them to warm to a comparable level. So as they warm more slowly, the growing temperature differential between them and the atmosphere starts to limit the temperature growth of the atmosphere. Personally I am surprised that the figure estimated for the 'in the pipeline' rise is only 0.6, I would have thoght higher. But that is only gut feel, not calculation. "If we were all honest about this we'd admit that at this stage that is little more than an idea which is around simply to fill an embarassing hole in an equation. " As I said, Its thermodynamics, not just an idea. And what is this hole you are referring to anyway? "There are other explanations which could replace "warming in the pipeline" which seem to me no more or no less plausable." Such as?
  40. What constitutes 'safe' global warming?
    Agnostic, at 2+ ppm of co2 being added per year it will take 30 years to make it to 450 ppm at the current rate. We will see if that will speed up or slow down, but that is the current rate. At this rate by 210 we will near near 570 ppm. We would of doubled.
  41. What constitutes 'safe' global warming?
    Daniel (38) Thanks. The URL is http://pubs.giss.nasa.gov/docs/2008/2008_Hansen_1.pdf Hansen argues, with some conviction, that CO2-e concentration of 450 ppm is too high to limit temperature increase to 2C by 2100. I think he is right and that we probably approach a dangerous tipping point when concentrations exceed 400 ppm. CO2-e concentration is already 388 ppm and rising at an accelerating rate because of our reliance on and increasing use of fossil fuels to meet our energy needs. Don’t you think it rather disconcerting that the IMF should be lending billions for the building of coal fired power stations (http://www.smh.com.au/world/world-bank-spends-billions-on-coal-power-20100916-15emx.html) at a time when the world should be contracting rather than expanding the use of coal.
  42. Extreme weather isn't caused by global warming
    Here is a statement of what should be the new paradigm: Weather in a given region occurs in such a complex and unstable environment, driven by such a multitude of factors, that no single weather event can be pinned solely on climate change. In that sense, it's correct to say that the Moscow heat wave was not caused by climate change. However, if one frames the question slightly differently: "Would an event like the Moscow heat wave have occurred if carbon dioxide levels had remained at pre-industrial levels," the answer, Hansen asserts, is clear: "Almost certainly not." The frequency of extreme warm anomalies increases disproportionately as global temperature rises. "Were global temperature not increasing, the chance of an extreme heat wave such as the one Moscow experienced, though not impossible, would be small," Hansen says. The map on that page makes it clear exactly what is meant by extreme variability:
  43. Royal Society embraces skepticism
    Dr Romm had an interesting discussion on this here: http://climateprogress.org/2010/09/30/royal-society-climate-science-summary-guide/
  44. What constitutes 'safe' global warming?
    HR@39 If you see the head of a lion or a snake coming through the window, you really, really do not want to wait until the whole body is inside the room before you shout a warning. Once you recognise the shape, and you see/hear/smell that it isn't just a silly kid with a mask, you act. Promptly.
  45. What constitutes 'safe' global warming?
    HR - so what are contrary papers to this estimate then? Seems to fit well with other estimates Hare and Meinshausen, Wigley and Matthews & Weavers.
  46. What constitutes 'safe' global warming?
    No disrespect but I do find it funny the casual way you drop in the " 0.6°C warming in the pipeline" as if it's a concrete fact. If we were all honest about this we'd admit that at this stage that is little more than an idea which is around simply to fill an embarassing hole in an equation. There are other explanations which could replace "warming in the pipeline" which seem to me no more or no less plausable. The certainty with which you can drop such statements is worrying.
    Response: Warming in the pipeline isn't a case of trying to account for less than expected warming. On the contrary, it's the inevitable consequence of a physical system with thermal inertia. If you're heating a pot of water, it doesn't instantly become hot. Similarly, if you're adding longwave radiation to the world's oceans, they don't reach equilibrium temperature instantly but take time to approach equilibrium.

    The climate time lag is an often misunderstood phenomena. I once tried explaining it but looking back at that post, I did a terrible job (for some mad reason, I thought using mathematical equations made it easier to understand - a sign of how much I had to learn about communicating science at the time). I'm planning to have another crack at it soon - using funky diagrams rather than equations.
  47. Climate Cherry Pickers: Falling sea levels in 2010
    Staggering, The Ville, staggering.
    "All told, 18 percent more water fed into the world's oceans from rivers and melting polar ice sheets in 2006 than in 1994, with an average annual rise of 1.5 percent."
    I would venture to use the term 'everlasting gobstoppery', for the first time. (shakes head, wanders away) The Yooper
  48. Carbon Dioxide - Everyone's Favorite Pollutant
    JMurphy @ 88 If you like direct marketing, to each his own. However, producing and distributing the stuff inevitably carries a significant carbon footprint - fuel to power the machinery to chop down the trees, to generate electricity to power the mill, the printing presses, to transport the paper, etc. Of course, most Western democracies enshrine the right to propagate direct marketing under the right of freedom of speech. I guess you're right - it does generate income though I question whether it's value for money. By contrast, those who market tobacco claim that they do so only to promote brand discrimination, not to generate sales, whilst seeking refuge under freedom of speech. So I give you credit for consistency and for backing up your argument.
  49. It's the sun
    KR #625 I quite like to recommend this book to people who want to get started with statistics. Although a lot of applied statistics is a bit of a black art that comes from experience of analysing your own data. I'm open to the idea of writing a piece on statistical basics when time permits, but what would be nice would be a statistical naïve to collaborate with :)
  50. It's the sun
    John Cook - Perhaps a statistical analysis thread would be helpful? I'm afraid I'm not the person to write it, unfortunately...

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