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Comments 51 to 75 out of 78:

51. Jesús Rosino at 21:41 PM on 10 March, 2011
    As well as nights warming faster than days, I would add winter warming faster than summer (if it was the sun, it would be the other way around), mentioned in the Scientific Guide to Global Warming Skepticism.
52. Berényi Péter at 04:13 AM on 22 March, 2011
    In the advanced version of The human fingerprint in global warming dana1981 writes: "Trenberth et al. (2009) used satellite data to measure the Earth's energy balance at the top of the atmosphere (TOA) and found that the net imbalance was 0.9 Watts per square meter". This proposition is false. What Trenberth has actually found in said paper is this: "There is a TOA imbalance of 6.4 W m⁻² from CERES data and this is outside of the realm of estimates of global imbalances that are expected from observed increases in carbon dioxide and other greenhouse gases in the atmosphere" That is, Trenberth says satellite data are useless for measuring Earth's energy balance. Then he continues: "The TOA energy imbalance can probably be most accurately determined from climate models and is estimated to be 0.85 ± 0.15 W m⁻²". So. The energy imbalance is not measured, it is determined using computational climate models. Then, what he actually did to satellite data is described like this: "An upper error bound on the longwave adjustment is 1.5 W m⁻², and OLR was therefore increased uniformly by this amount in constructing a best estimate. We also apply a uniform scaling to albedo such that the global mean increase from 0.286 to 0.298 rather than scaling ASR directly, as per Trenberth (1997), to address the remaining error. Thus, the net TOA imbalance is reduced to an acceptable but imposed 0.9 W m⁻² (about 0.5 PW)". That is, he increased both OLR and albedo relative to actual data by amounts he considered acceptable in order to arrive at an imposed value of TOA imbalance. Therefore it's not true he has "found that the net imbalance was 0.9 Watts per square meter", but took a value based on model calculations and imposed it on satellite measurements. What Trenberth did is questionable, but defensible in a sense. Whenever you have next to useless data with unknown but large error margins, you either throw it away or do odd things to it in the hope at least something can be saved. If the data are as expensive to collect as CERES data are, NASA scientists have no choice but follow the latter path. On the other hand grave misrepresentation of Trenberth's pain as it is put by dana1981 above, is indefensible. Calculations can be verified against measurements, but they can never be verified against (the same!) calculations. That is, Trenberth's figure of 0.9 W/m² net imbalance at TOA is still an unverified claim. There is an important difference in science between true and false statements. The latter kind implies anything along with its own negation, therefore it's a bit ill suited for deriving meaningful results.
53. jomamax at 12:27 PM on 10 July, 2012
    Dikran, KR + Julian. I have no background in climate, I'm a computer scientists; loving your debate. KR is correct in saying that since we did add 'xyz' amount of CO2, then it is humans who can be attributed to that amount - but KR/Dikram - Julian is correct to point out that it could be entirely meaningless. KR you are throwing straws on the camel's back, maybe you broke the camels back, Julian is pointing out that your straws - though technically 'added' are irrelevant given that others were adding and removing straws from the camels back by an unknown amount. KR - Julian is not proposing a 'Green Little Man' argument - he's indicating that the other sources/sinks for CO2 could indeed be quite vast. If they are - and they are highly variable - then his assertions are not only correct, but meaningful. You are sharing a bank account with a 'black box'. You know the black box withdraws and adds X amount every month. You know that you add $16 every month. The bank account seems to be rising by ~$16 every month. You know for sure that the 'black box' NET contributions monthly are 0 - but you have no idea why, or what the net attributions are. To KR's point, it is reasonable to conclude that since you are adding $16 every month - well - you are adding $16 every month - no doubt about it. KR is technically correct - but his point may be mute. Julian's point is that the black-box may be inserting/removing 1000's every month - you don't know. If this is the case - then KR your point is mute - it doesn't matter if we are adding $16 a month. Dikram, your analysis would be off. The Dikram/KR/Julian debate boils down to this: If the plus/minus CO2 contributions via sinks/sources from 'non man made sources' (I'n not going to use the proper scientific term since I'm not sure of it's meaning) is rather large, and it varies quite a lot over time - then Julian's position is not only technically correct, but it is very valid. If those net contributions can be definitely characterized as stable and small, then we can safely follow Dirkam's points on the matter and KR's point that 'we are adding X amount every year' matters - because our contributions are meaningful. I'm guessing however, that we don't really understand the size and magnitude of these other heat-sinks, and that they may be highly variable. If this is the case then Julian's point should be considered. KR is technically correct but his point is mute - and Dikram's analysis must be flawed.
54. KR at 13:40 PM on 10 July, 2012
    jomamax - I would have to forcefully disagree. If we know: * We are contributing X to the bank balance * We know the total balance to be increasing at X/2 Then: * Other contributions and deductions from that balance are such that other contributions are X/2 less than deductions; that the other influences on the balance are a net sink. It doesn't matter how much those other contributions/deductions vary in toto - the difference between them is established to be negative X/2 by observing our contributions and the total balance. By knowing how much CO2 we put out and how much the atmospheric levels increase - we know two of the four values, and hence we really do know the difference between the other two. Stable, varying, whatever; it just doesn't matter. We know what the difference is between the natural sinks and sources, and it adds up to about half of our emissions - nature is a net sink. There's just no other way possible to work the math, barring Little Green Men (LGM's) adding or subtracting carbon from the biosphere. And if you make that kind of causal assertion, well, I'm going to feel completely justified at laughing...
55. Bob Loblaw at 14:27 PM on 10 July, 2012
    This debate is also going on in the Murray Salby thread. jomamax: you have several "ifs" that are "aren'ts". 1) "black-box may be inserting/removing 1000's every month - you don't know.". Yes, we do know, with a fair degree of accuracy (but not perfectly). The known fluxes in the carbon cycle don't have error bars that large. 2) "If the plus/minus CO2 contributions via sinks/sources from 'non man made sources' (I'n not going to use the proper scientific term since I'm not sure of it's meaning) is rather large, and it varies quite a lot over time". It is large, but it's not varying that much over time - at least, not in amounts that we don't know about (point 1). CO2 was fairly steady (with a seasonal cycle) for a long time before people started burning fossil fuels, and we know a lot about the cycles. 3) "If those net contributions can be definitely characterized as stable and small,". They don't need to be small, and they don't need to be stable for us to have reasonable estimates of them. You'd need to have large, variable errors in the measurements of those fluxes, and that's not the case (point 1). 4) "I'm guessing however, that we don't really understand the size and magnitude of these other heat-sinks". You'd be guessing wrong. (I presume you meant CO2 sinks.) In addition, you have to remember that in the bank balance scenario, you are also using marked bills. Unless the other sources/sinks are marking the bills exactly the same way, the source is obvious. CO2 from fossil fuels is depleted in C14, and has a C12/C13 mix that does not match other sources of CO2 that are depleted in C14.
56. Dikran Marsupial at 20:05 PM on 10 July, 2012
    jomamax The mass balance argument is correct regardless of how large natural emissions are. It is easy to show why this is true using the savings analogy. Say I share a savings jar with my wife (who represent the natural environment), that is guarded by loyal ninja to make sure only she and I can make deposits and withdrawals. If I put in $16 a month and notice that our savings rise by only $8 a month, then I know that my wife is spending $8 more a month than she is saving. This is true whether she saves $1 a month and spends $9, or if she saves $10 a month and spends $18, or if she saves $100 a month and spends $108, ..., or if she save $1,000,000,000 and spends $1,000,000,008. As it happens, we do know that natural emissions are much larger than anthropogenic emissions. We know this because the residence time of CO2 in the atmosphere is only 4-5 years, which means there must be a very large exchange flux that swaps about 20% of atmospheric CO2 each year with CO2 from the oceans and terrestrial biota. However this exhange is just that, a straight swap of CO2 between reservoirs, and has no effect whatsoever on atmospheric CO2 concentrations. As Murray Salby says, it is only the difference between total emissions and total uptake that matters, and the mass balance equation shows that even if natural emissions are much bigger than anthropogenic emissions, natural uptake is bigger still. This means the natural environment is actively opposing the rise. If you think Julian is right and the absolute magnitude of natural emissions matters (rather than the difference between natural emissions and natural uptake), then it should be possible for you or Julian to come up with a counter example, in the form of values for natural emissions, natural uptake, anthropogenic emissions and the annual rise in CO2, where the natural environment is a net carbon source and the observed rise is less than anthropogenic emissions, and doesn't violate conservation of mass. You will find that you can't. Note I challenged Julian to do so, and he ducked the challenge, and did not reply to my post pointing out that he had ducked the challenge.
57. Falkenherz at 20:04 PM on 2 August, 2012
    Hi and thank you all for this very interesting and enlightening discussion. Great website here! If I understand correctly, the LGM ("little green men") point is the key point here. The mass balance is right by logic, but I think Julian points out that the mass balance may not be all about it (might be "the wrong level of abstraction") because nature sources/sinks might not be as constant as we assume. Let me try the challenge issued by Dikran: year 1: +70.000 natural +200 humans -70.100 natural -> +100 year 2: +70.000 natural +0 humans -70.100 natural -> -100 so far the mass balance argument, as I understand it. Now suppose the "little green men" like this: year 3: +70.000 natural +0 humans -69.900 natural -> +100 or, with human contribution still in the picture, like this: year 2bis: +70.000 natural +200 humans -70.050 natural -> +150 What has happened here? Little green men? Yes, but natural little green men, if you will. In year 3, human is still +0, but a natural sink suddenly decreased, by a small amount. Or, alternatively, in year 2bis, human is still contributing, but natural sinks have suddenly decreased. This is outside the mass balance argument, but this seems to be Julian's point: Nature's part is so huge in comparison, that even small fluctuations may happen arbitrarily, which completely make human's part arbitrary in the long term picture. Julian, does this capture your point? Of course, this is just about that the mass balance argument alone is not enough. If we add indications, theories and evidence, we should be back to the result that human contribution is decisive, because any such thinkable natural fluctuations have not been evidenced so far. And I think that is the core of Julian's criticism. Is that conclusion from evidence valid? Basically, you all here point out, yes. But why? But this refers to a point made from outside the mass balance logic, so maybe we should admit to that the mass balance argument alone is not proof, but rather strengthens existing evidence? If we came so far, how exactly is existing evidence strengthened by the mass balance? Because the past shows us clearly a constant natural net (200ppm), until human contribution kicks in (to 395ppm)? How do we know human contribution is +195ppm? If I understand correctly, fossil isotopes in the atmosphere are only about 5%, which would be roughly 20ppm. So, there is even more evidence to be linked. Which?
58. DSL at 00:49 AM on 3 August, 2012
    Falkenherz, I believe Tom Curtis has addressed some of this recently here. It should probably be incorporated into this article.
59. Falkenherz at 01:43 AM on 3 August, 2012
    DSL, I read it, and it provides for several indicators of evidence. But I meant specifically the mass balance argument, and the comments here provide for much more detail already than in that article. I, as Julian, might just have a gap of logic here, and I hope that listing these very simplified figures will make it clear for me, if someone can point it out where they goe offroad.
    Response: [DB] A deeper-level analysis of the mass-balance problem for "skeptics" is found here.
60. Falkenherz at 01:17 AM on 4 August, 2012
    Thanks, I will be commenting over there.
61. CBDunkerson at 03:38 AM on 4 August, 2012
    Falkenherz, the problem is that your example assumes we only know one variable... the total atmospheric accumulations (the end result of each of your calcualtions). That is incorrect. We know accumulations and human emissions. The mass balance argument only works when using both of those values. Thus, your counter argument is 'correct' only if we ignore some of the data we have.
62. Glenton Jelbert at 15:07 PM on 26 September, 2012
    I wrote to Prof Essenhigh a couple of years back when his paper came out. Not having received a response since, I thought I'd write an open letter to him: Open letter to Prof Essenhigh Brilliant that there's a peer review response now (Skeptical Science's Dikran Marsupial's response)
63. Carbon500 at 07:11 AM on 4 October, 2012
    Response to Sphaerica from 'Inuit Perspectives on Recent Climate Change' - transferred to this thread at moderator's request. Sphaerica: Just to reinforce my point – more observations from the real world. Ice conditions in the Baltic Sea vary a lot from one year to another. The maximum ice covered area varies between 52,000 and 422,000 square kilometres(12-100 per cent of the total Baltic Sea area) Baltic Sea Portal: itameriportaali.fi/en/tietoa/jaa/jaatalvi/en_GB/jaatalvi Clearly the Baltic Sea has remained free of the malign influence of CO2. Here’s more: JOURNAL OF GEOPHYSICAL RESEARCH, VOL. 106, NO. C3, P. 4493, 2001 doi:10.1029/1999JC000173 'Influence of atmospheric circulation on the maximum ice extent in the Baltic Sea' Anders Omstedt Swedish Meteorological and Hydrological Institute, Norrköping, Sweden Deliang Chen Department of Earth Sciences, University of Göteborg, Göteborg, Sweden This work analyzes long-term changes in the annual maximum ice extent in the Baltic Sea and Skagerrak between 1720 and 1997. It focuses on the sensitivity of the ice extent to changes in air temperature and on the relationships between the ice extent and large-scale atmospheric circulation. A significant regime shift in 1877 explains the decreasing trend in the ice extent. The regime shift indicates a change from a relatively cold climate regime to a relatively warm one, which is likely a result of changed atmospheric circulation. In addition, the analysis shows that a colder climate is associated with higher variability in the ice extent and with higher sensitivity of the ice extent to changes in winter air temperature. Moreover, the ice extent is fairly well correlated with the North Atlantic Oscillation (NAO) index during winter, which supports the results of earlier studies. However, the moving correlation analysis shows that the relationship between the NAO index and the ice extent is not stationary over time. A statistical model was established that links the ice extent and a set of circulation indices. It not only confirms the importance of the zonal flow but also implies the impact of meridional wind and vorticity. The usefulness of the statistical model is demonstrated by comparing its performance with that of a numerical model and with independent observations. The statistical model achieves a skill close to that of the numerical model. We conclude that this model can be a useful tool in estimating the mean conditions of the ice extent from monthly pressures, allowing for the use of the general circulation model output for predictions of mean ice extent. Finally, the globe is warming? Is it? http://data.giss.nasa.gov/gistemp/graphs_v3/Fig.C.gif
64. KR at 07:35 AM on 4 October, 2012
    Carbon500 - With regards to your extended reference, yes, ice extent certainly does vary based on a number of influences. Relevance? In regards to the graph you refer to, containing temperature data only from 1996, I would refer you to the Did global warming stop in 1998, 1995, 2002, 2007, 2010 thread. Cherry-picking short intervals proves nothing about long term trends - that's weather. If you look at those long term trends, however, at climate, you see something quite different (GISTEMP and 10 year averages).
65. Bob Lacatena at 10:14 AM on 4 October, 2012
    Carbon500, Sorry, but your gish-gallop is 100% silliness. My original point was: "And what evidence do you have that your anecdotal evidence is equivalent to what we are seeing today?" And you respond with yet more anecdotal evidence, in this case, a narrowly focused view of ice in one part of the world, as if that is then evidence that the entire globe is not warming. I'm sorry, Carbon500, this is a 100% fail. You're going to have to try a lot harder than just listing whatever papers you can find with google-search.
66. skywatcher at 12:39 PM on 4 October, 2012
    Carbon500, from your post here: I've seen a reproduction of this quote in quite a number of places - it seems to be a bit of a darling quote of the so-called 'skeptics' - a report from the early 20th Century indicating that conditions in the Arctic are notably warmer than in the late 19th Century. You quoted this as though it's somehow surprising or that it refutes anthropogenic causes for global warming. A 1920s observer in the Arctic might notice that, compared to the late 19th Century, glaciers had retreated somewhat and that sea ice was reduced in extent. An observer in the early 21st Centuey can observe that the same glaciers are considerably further back and continuing to retreat at a rapid rate [Some slightly readvanced in the 1960s-1980s in response to favourable conditions in the 1960s and 1970s]. A 21st Century glacial geomorphologist can observe that glaciers in Iceland, Norway, the Alps and elsewhere reached their greatest "Little Ice Age" extent in the late 19th Century (historical records, lichenometry etc) leaving large moraines behind. This is no surprise! We know there has been warming sice at least the late 19th Century. We have a pretty good idea of the causes of the warming through the 20th century: early warming had a large component of solar activity and a reduction in volcanic activity in addition to the initial component of post-Industrial Revolution greenhouse gas emissions. As we moved through the 20th Century, the GHG forcing increased to be the strongest of all the forcings, such that we cannot explain our current trajectory of warming if we ignore GHG physics (unless you believe in climate fairies, which I don't). The Arctic is continuing to respond to those forcings. The skeptics' claims that early 20th Century observations of the beginning of the thaw of the high Arctic, which is contiuing through the present day somehow contradicts our understanding of GHGs and climate, is frankly absurd. It's a transparent attempt to mislead the unwary reader by drawing a false parallel between the 1920s and today. We see that the Arctic is a much less ice-covered place than it was 40 (or 80, or 120 years ago), an observer in the 1920s saw that the Arctic was less ice-covered than in the 1880s. That 1920s observer would be astonished to see how little ice is in the Arctic now compared to the 1920.
67. Carbon500 at 03:39 AM on 6 October, 2012
    KR: The point I made is that ice melting depends on many influences, and I think that caution is needed when attributing ice melt extent to CO2. That’s why I gave the Omstedt and Chen reference as an example. Regarding global temperatures, I am of course aware of the other graphs you mention, and the argument that the current stalling of warming is too short a period from which to draw firm conclusions – and yes, I am aware of the difference between weather and climate. (-snip-)? Sphaerica: (-snip-). Skywatcher: We agree that warming has in essence been in progress since the 19th century, but I’m more cautious than you about the 20th century. (-snip-). Another reason for my caution goes further back in the climatic record. (-snip-) Clearly Nature can surprise us. (-snip-) (-snip-). (-snip-)?
    Response: [DB] Multiple off-topic and inflammatory snipped. As constructed, this comment comprises a Gish Gallop. Future such comments will be deleted in their entirety.
68. KR at 04:33 AM on 6 October, 2012
    Carbon500 - In some respects the graph you posted earlier is very interesting. Go to the Temperature Trends tool here, and look at GISTEMP (I will note in passing that you did not identify the source of your graph, or the selections from which it was generated - very bad form). Set a starting point of 1996 and smoothing of 1 month, as per that graph (source identified only from the URL), and look at the trend. 2σ uncertainties are calculated with added uncertainty due to autocorrelation, so this is a reasonably conservative estimate. Trend: 0.123 ±0.130 °C/decade (2σ) What does this set of data mean? There is a temperature trend of 0.123°C/decade, but it is is not quite statistically significant over that period. More data, more time is needed to truly distinguish that trend from the null hypothesis of no warming. But even your "no warming" example actually shows warming consistent with 30 and 40 year trends. Your claim that "this sixteen year old record cannot be ignored" is a strawman argument (it's not ignored, but it's not statistically significant - it's part of the data that is statistically significant), and indicates that you are lacking in statistical insight - as your presented evidence contradicts your claims (since it indeed shows warming). In other words, your use of that graph in an attempt to claim no warming is (IMO) quite demonstrative of denial myths - myths that sources like SkS are (I am happy to see) working to dismiss as the silliness they are. Finally, regarding experimental evidence of CO2 trapping heat - take a look at Harries 2001 directly showing energy entrapment at CO2 frequencies, which is discussed here regarding incremental effects as well as here regarding empirical evidence. If you disagree with the evidence, present your evidence on the appropriate threads. WRT water vapor, search using the SkS "Search" box for water vapor, or look at Google Scholar. Your claim that the role of CO2 as a greenhouse gas hasn't been experimentally proven is, to be blunt, complete and unsupported nonsense.
69. Carbon500 at 20:41 PM on 15 October, 2012
    KR: Sometimes it's useful to stand back and just look at the contours of a graph rather than playing games with trend lines and placing all your faith in statistical results. I have a good reason for saying this. In an industrial research project on which I was engaged many years ago the statistics of a crucial experiment showed significance (and yes the correct test was used, in case you're wondering), but because I was suspicious further experiments ensued and a great deal of time and money was subsequently saved on the project on which I was engaged. The section of graph I'm talking about is quite different in character from what precedes it. Never mind, you look at it your way, I'll look at it mine. Where have I made the claim that the role of CO2 as a greenhouse gas hasn't been experimentally proven? Have I even suggested that I have issues with satellite data? Had you read what I said properly, you would have noted that I was enquiring as to whether a laboratory experiment using an artificial atmosphere had ever been carried out to assess the effects of CO2.
70. CBDunkerson at 22:07 PM on 15 October, 2012
    Carbon500 wrote: "Sometimes it's useful to stand back and just look at the contours of a graph rather than playing games with trend lines and placing all your faith in statistical results." So... avoid any hint of actual math and just let your preconceived notions guide your 'understanding' of the data? "The section of graph I'm talking about is quite different in character from what precedes it." True, in that it does not show as rapid an increase in atmospheric temperatures... but you implied ("Finally, the globe is warming? Is it?") that it doesn't show an increase at all, which is simply false. Even if it weren't false it would be the wrong graph for what you purport to be disputing. That's a graph of lower atmospheric temperatures, not "the globe". The oceans of the world are a vastly greater reservoir of energy than the lower atmosphere... and measurements of ocean water continue to show a high rate of warming. Finally, even if we could use just the lower atmosphere to determine whether the globe was warming, while ignoring the vastly more significant oceans, and we pretended that the lower atmospheric graph you posted did not show the warming trend it actually does... your 'conclusions' would still be wrong because there has been extensive research on the various factors at play in atmospheric temperatures over the past hundred years and the 'difference in character' you note has been explained by measured changes in factors other than the greenhouse gas forcing. Basically, greenhouse gas warming continues to increase and is the primary driver of the continuing warming trend. The short term variability you cling to is the result of other smaller factors (e.g. solar radiation, volcanic eruptions, soot, et cetera) varying up and down enough to change the slope of the trend over short time frames... but not enough to stop the inexorable upwards march.
71. KR at 07:46 AM on 16 October, 2012
    Carbon500 - "Where have I made the claim that the role of CO2 as a greenhouse gas hasn't been experimentally proven?" Let me refresh your memory. In your last post, which I replied to before it was snipped for being a Gish Gallop, you said:

    Does this really mean that the foundation stone of the CO2 story hasn’t been verified experimentally, and that calculated forcings are all the evidence there is?

    You did indeed make that claim - and it is indeed completely unsupportable given direct evidence such as Harries 2001.
72. Carbon500 at 20:24 PM on 16 October, 2012
    KR: It depends on what you mean by an experiment. To me an experiment is something which has been set up so that variables can be controlled by the experimenter, hence my comments regarding an artificial atmosphere. CBDunkerson: the graph I'm talking about is entitled 'Monthly Mean Global Surface Temperature'- you don't agree with the way I see it; so be it. (-snip-)
    Response: [DB] Off-topic snipped. Please follow the link that Adelady was kind enough to provide for a discussion of that newspaper article.
73. adelady at 22:11 PM on 16 October, 2012
    carbon500, You need to check out the latest SkS post.
74. CBDunkerson at 23:25 PM on 16 October, 2012
    Carbon500, if you make reality a matter of perception then we have no common basis for discussion. Either the globe consists of more than the surface atmosphere (e.g. oceans, higher layers of the atmosphere, et cetera) or it does not. Either the graph you posted showed a warming trend or it did not. If you truly believe the 'not' position on either of these issues then 'the way you see it' is at odds with perceived reality 'the way I see it'.
75. Carbon500 at 02:03 AM on 17 October, 2012
    adelady: thank you for your comment. CBDunkerson: I agree - clearly we have no common basis for discussion. Ditto KR.

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