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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 67551 to 67600:

  1. Updating the Climate Big Picture
    @Dikran Marsupial. The reason why the IPCC does not make the link, as you reckon they should, is because we need to unequivically prove that the amount of greenhouse gas produced by man and not re-absorbed in the carbon cycle, is responsible for global warming. At the moment, it's 'very likely', but to move it to be unequivical will, unfortunately, take a lot more proof. The problem that we have is that the climate is obviously very complex, and the interaction between natural and manmade forcing agents and other feedback mechanisms isn't wholly understood. The problem with claiming that we have 'unequivical' proof that the link is made, is that this would mean that the public would expect us to be able to reliably predict the global mean temperature within a short time frame, 5 years, say, to a degree of accuracy comparable to what they expect from other unequivically proven scientific theories. I would expect that with each report publication, our degree of confidence will be raised each time, which will increasingly move public opinion in our direction.
  2. Dikran Marsupial at 22:05 PM on 24 December 2011
    Updating the Climate Big Picture
    mace if 2. That mankind is responsible for the increase in the percentage of greenhouse gases resident in the atmosphere is 'unequivical' and 3. That greenhouse gases trap heat is 'unequivical' How can the direct link between 2 and 3 be anything other than "unequivocal"? GHGs are GHGs whether they are due to anthopogenic emissions or not. Furthermore you do not appear to understand the link between 2/3 and 1. If it is unequivocal that anthropogenic emissions are increasing the amount of GHGs in the atmopshere and that it is unequivocal that GHGs trap heat, then it follows that it is unequivocal that all things being otherwise equal we are causing the Earth to warm. The only uncertainties lie in changes in other forcings and unforced climate variability. The uncertainty due to the former is fairly small; the variability of the latter is enough that scientific honesty means that we should not claim that the rise actually observed can be unequivocally attributed to our emissions. None of this is a rational reason for skeptics to doubt that our emissions are afecting the climate, and suggesting that an unequivocal link should be required to silence the skeptics is deeply misguided. The deniers will accept any uncertainty to support their view, no matter how small. The correct argument to make is that there can be no absolute proof of a causal relationship regarding the real world based on observational or experimental evidence. PLEASE can you read more widely before posting, you are still contributing to the noise rater than the signal.
  3. Updating the Climate Big Picture
    @Tom Curtis, I'd be very worried if anybody on here wasn't completely familiar with the IPCC 4th report, which is the basis on which our concensus holds. The IPCC 4th report uses the following strictly defined terms:- 'unequivical' i.e. 100% confidence 'very likely' i.e. >90% confidence 'likely' i.e >60% confidence. The phrase 'settled science' isn't used but could be construed in most people's minds to be closer to 'unequivical' than to 'very likely', whereas they are a long way apart. The IPCC report says the following:- 1. That there has been a warming trend since 1978 is 'unequivical' 2. That mankind is responsible for the increase in the percentage of greenhouse gases resident in the atmosphere is 'unequivical' 3. That greenhouse gases trap heat is 'unequivical' 4. That items 1 and 3 are directly linked to item 2, is 'very likely'. We need to carry on focussing on making the link in item 4, but claiming that this link is 'settled science' means that we have a complete understanding of the climate, which isn't yet the case. We need to continue the work so far, so that we can turn 'very likely' in to 'unequivical' and finally silence the skeptic-deniers.
  4. Updating the Climate Big Picture
    James Wilson, setting aside the points others have made about the lack of factual grounding in your comments... it needs to be pointed out that NASA temperature data is virtually identical to the BEST data. Frankly, your insinuation of 'questionable' data is nonsensical given that BEST was used because it is a 'skeptic' data set. Feel free to use NASA data instead. The results don't change. mace, in addition to Tom's points, you should realize that, "the link between this [humans increasing greenhouse gas concentrations] and global warming" is basic physics, and thus somewhat more than just 'very likely'. If the quantity of greenhouse gases goes up then the greenhouse effect increases (i.e. more IR radiation is retained in the atmosphere) and you have global warming. The only people who dispute that are crackpots and those who have been misled by crackpots. All of the prominent 'skeptic' scientists (e.g. Pielke, Spencer, Christy, Plimer, et cetera) concede that human greenhouse gas emissions are causing global warming.
  5. Making Arctic Sea Ice Loss Real
    Good visualisation of area lost. What about mass lost? Presumably this would be even more dramatic.
  6. Philippe Chantreau at 18:15 PM on 24 December 2011
    Updating the Climate Big Picture
    James Wilson, the strange assertions that you make must be supported, otherwise it's just trash talk about the work of others. What does "scientifically defensible" mean? Who are these "external people" and what have they published in the litterature? What are the "known biases"? In what papers were these biases analyzed? When I say papers, I mean peer-reviewed science papers from serious journals. You talk about getting back to the science but you don't provide any scientific reference to a lenghty set of wild assertions. If you decide to respond with anyting specific, make sure it is on an appropriate thread.
  7. Ocean Acidification Is Fatal To Fish
    John Russell@18 Thanks for the link to the pdf on OA. It really opened my eyes to a problem I have read about, but did not understand at all clearly. Near the end of the document, there is a chart showing various CO2 mitigation strategies we could implement and one of them is shown as 'BECS', which I googled and the best match I found was "Bio Energy to Carbon Sequestration": would that be right? I am alarmed at the lag in OA vs CO2 increase, meaning that OA is going to increase for a long time, even if we stop pumping CO2 into the atmosphere today. Evidently, there are no brakes on our steam-roller. Good thing I am not fond of sea-food: perhaps that is a benign genetic mutation for me (grin). We really are a dangerous species! Sigh.
  8. Making Arctic Sea Ice Loss Real
    For further comparison, that is: 8% of the area of Asia, or equal to the combined territories of India, Nepal, Bagnladesh and Buhtan; 31% of the area of Africa, or equal to the area of Sudan, South Sudan and Libya; and 20% of the area of South America, or equal to the combined areas of Brazil and Colombia. Sorry, no maps.
  9. Making Arctic Sea Ice Loss Real
    And for the Land down under: (Original map from wikipedia) The shaded area is actually 3,740,000 km^2 (give or take)or about 4% oversize for the comparison. {That's the disadvantage of not having nice small states like Texas for fine tuning ;)} The area of lost ice represents 47% of Australia's territory including Tasmania, but not the Australian Antarctic Territory.
  10. Ocean Acidification Is Fatal To Fish
    27, mace, Actually, there has been no time in the Pleistocene Epoch where CO2 levels rose above 300 ppm (so "spiked" from 285 to 300 is a bit of a stretch), but it does hint at exactly how deadly what we are doing to the atmosphere may be. From my post a few weeks ago (you should give it a read), (Fahrenheit) 451 ppm:
    During the Eemian, an interglacial period that began roughly 130,000 years ago and lasted 16,000 years, temperatures in Europe north of the Alps were roughly 1-2˚C higher than today. Sea levels were 4 to 6 meters higher. CO2 levels were roughly at 300 ppm. Going further back, during a warm period 3 million years ago within the Pliocene epoch, temperatures were a mere 2-3˚C warmer than today (see here and here and here). Sea levels were 25 meters higher. CO2 levels were between 360 ppm and 400 ppm.
  11. Ocean Acidification Is Fatal To Fish
    mace: skeptic-deniers can point to the spikes that occurred during the pleistocene period as being greater than what happened today, In the first place, "skeptic-deniers" have proven repeatedly that they will believe -- or at least say -- just about anything to avoid confronting the reality of AGW. That being the case, I don't think there's any reliable way to "skeptic"-proof graphs (beyond following existing standards for scientific practice). If all else fails, they'll find a way to attack the attempt to make graphs "skeptic"-proof. Any port in a storm, as the saying is. "Skeptics" who point to the Pleistocene ignore the current rate of temperature change, and they also ignore the fact that the Earth now has a population of about 7 billion people (and growing) who are more or less dependent on the environmental status quo. The proper response to the claim you bring up is to point out that it's irrelevant to modern civilization, its infrastructure, its fisheries, blah blah blah. Anyone who can't see that has a vested interest in not seeing it.
  12. Foster and Rahmstorf Measure the Global Warming Signal
    #74-77 : thank you all for the different precisions. Papy is right, FR2011 reference is explicitly this GISS source, dealing with stratospheric aerosols only (so volcanic activity). For tropospheric aerosols, both natural and man-made, interesting regional estimates in Streets et al. 2009 , to read with muoncounter's reference. But this is outside the scope of FR2011. Aerosols are clearly still difficult to constrain, for their emissions as well as their effects, but Bob's explanations for analysis methods are interesting.
  13. Updating the Climate Big Picture
    mace @24, you need to quote the section of the main article which calls something settled science and the equivalent claim from the IPCC which is called "very likely" (>90% likelihood). Otherwise your sentence is post is meaningless. As it stands I cannot find anything called "settled science" above which the IPCC only calls "very likely".
  14. Updating the Climate Big Picture
    This is an excellent piece of work, thanks. It is probably the most important information that this site puts out because it will do most to convince those who are confused by the opposing views that they are presented with in the media, yet becoming sufficiently worried about it to seek better information. On a technical note, I would like to see more emphasis on the projected sea level rise and its likely non-linear progression (re. Hanson and Sato). For instance, the U.K. government in its infinite wisdom is spending an absolute fortune, which it can ill afford, on the Olympic Games in a city that is vulnerable to sea level rise. The time will likely come in the not too distant future when the chosen site for the games will only be suitable for water-sports, which will, of course, work wonders for real estate values. Long before then, Canute like, there will need to be a new Thames Barrier unless they, the powers that be, wake up and take London to high ground, which won’t be cheap! (And they think that the current financial situation is bad.) It is amusing to read current plans for a new London airport in the Thames estuary, which, I assume, will be designed to accommodate modern versions of Sunderland and Catalina flying boats. Virtually all coastal cities are vulnerable in their own way. A potential three meter rise in sea level from the collapse of the West Antarctic Ice Sheet should concentrate the minds of many, especially of those that can’t swim. On a practical note, errors in proof reading will, in the minds of some, reflect errors in the science it discusses, which is a pity, considering the effort that has clearly gone into compiling it. Though having done some proof reading on my own publications, you have my deepest sympathy. I found the following: ‘theory?". Well’ ‘Unfortunately there is a there is a very vocal’ ‘Th good news’ ‘not to immeditately take’
  15. Updating the Climate Big Picture
    JamesWilson - "Can we get back to discussing science?" Yes, indeed. Like for instance who is taking the NASA dating apart and correcting mistakes? " If you want to convince a Global Warming skeptic" SkS does not attempt to convince fake-skeptics. The evidence for man-made global warming is overwhelming, and yet they still resist the evidence, throwing up one illogical objection after the other.Trying to convince those people is a futile exercise. Our objective is right at the top of the home page: Explaining climate change science & rebutting global warming misinformation
  16. Updating the Climate Big Picture
    JamesWilson#23: Your objections to BEST make no sense; that data set was gone over with a fine-toothed comb. See the several existing BEST data threads. What NASA data are you referring to as 'more scientifically defensible' and how does this differ from BEST? Please be sure to cite your sources for these assertions; this is science we're talking about, not hearsay. In case you hadn't noticed, there are hundreds of posts here discussing specific aspects of science. No one is 'sweeping science away.' Many people think having one 'big picture' thread is a very good idea. If you are looking to discuss a specific point, find the thread that deals with it - and read the posting.
  17. Updating the Climate Big Picture
    iPCC use the phrase 'very likely' rather than settled. We should stick to the consensus view. Mankind adding gases to the atmosphere that cannot be naturally balanced is settled, but the link between this and global warming is 'very likely', rather than settled. Terminology is important.
  18. Updating the Climate Big Picture
    The choice of graphs seem a little questionable. BEST for example is a much poorer source of land data than NASA. Both have known bias but NASA has a lot more external people pulling the data apart and correcting their mistakes. This is likely to produce more accurate data. But more importantly: NASA produces more scientifically defensible data. This article really isn't going to convince *anyone* skeptical of the science behind Global Warming of *anything*. It also makes so many claims that it difficult to even discuss the science behind it. Can we get back to discussing science? If you want to convince a Global Warming skeptic that is the way. Sweeping science away in "the Big Picture" is what makes people skeptical of Global Warming theory in the first place.
  19. Updating the Climate Big Picture
    Thank you Rob
  20. Foster and Rahmstorf Measure the Global Warming Signal
    The links to AERONET and GAW that I posted are to networks of ground-based passive optical instruments that use direct sun readings to measure the atmospheric attenuation at specific (narrow range) wavelengths. The filters can be in the UV, visible, or near-IR portions of the spectrum, and are usually selected with particular types of analysis in mind (i.e., particular types of atmospheric aerosols). These sorts of instruments have several characteristics: - the direct sun reading does not tell you whether the attenuation is the result of absorption or scattering or both. - the direct sun reading does not tell you where in the atmosphere the aerosol is. It represent an atmospheric total. - the initial measurement tells you Total Optical Depth. Data analysis accounts for attenuation due to Rayleigh scattering. Depending on the wavelength, other adjustments are made for absorption by other known gases - e.g. ozone, water vapour, etc. The remainder becomes the Aerosol Optical Depth, and it is wavelength-specific. - depending on the purpose, wavelengths will be selected to avoid certain absorption bands, but you can also target them if you are trying to measure a particular gas (e.g., ozone). - how Aerosol Optical Depth varies with wavelength can tell you a lot about the aerosols - e.g., size distribution. - some instruments (AERONET in particular) take readings away from the sun. This allows identification of many other optical properties of the aerosols, including whether they are mainly absorbers (e.g. soot) or scatterers (e.g. dust). - clouds also have optical depths. Thin ones are measurable, but thick ones absorb everything and optical depth becomes infinite (mathematically). To get aerosol optical depth, analysis includes some sort of cloud screening, so that cloud doesn't get confused with aerosols. - all of this will allow some determination of what type of aerosol is present, and perhaps where it is in the atmosphere (e.g., volcanic dust in the stratosphere). There are other methods of measuring aerosols, such as aircraft sampling, or LIDAR. LIDAR is a laser-based active sampling method that sends light beams into the atmosphere, and measures the return signal. They are capable of creating atmospheric soundings of various optical properties. A quick Google search led me to this European network: EARLINET. I hope this helps clarify some of the characteristics of measuring aerosol optical depths.
  21. Updating the Climate Big Picture
    Michael - the figure is around 20,000 visits per day IIRC. And no where near 7 billion people have access to the internet. Billions are currently starving, so blogging is way down the list of their priorities.
  22. Models are unreliable
    JamesWilson -"Oddly the Jason-2 site shows the change and drop starting in 2010 but...... See SkS post: Sea level fell in 2010 And the latest update from AVISO
  23. Updating the Climate Big Picture
    At the risk of being off-topic here goes on big picture: - CO2 cumulates and incremental emissions have an atmospheric life of tens thousands of years [This is so if one assumes the sinks are cleaning up CO2 from many decades ago - the right way to look at it given the impending feedbacks]. - The general public and most politicians thinks CO2 is a smelly Fart that dissipates quickly once we reduce CO2 emissions. Governments are not interested in informing them otherwise. - Nevertheless this means paleoclimate comparisons are valid given CO2 is the main driver of global temperature for a constant solar irradiance. However, given that the rate of CO2 increase is now 10,000 times quicker than in paleoclimate Newton would not hesitate to claim the transition to Pliocene paleoclimate conditions will also be much much quicker. Basically 25m sea level rises for the 2C target and lots of other nasties. http://www.giss.nasa.gov/research/news/20111208/ http://www.youtube.com/watch?v=hK8BbOnvGJU - This wonderful website of yours gets 2 to 3 thousand users a day in a world of 7bn. It has done great work and is a fantastic resource. - But how can we change the understanding of the public to motivate the politicians ? Or is this off topic ? Best wishes.
  24. Models are unreliable
    James Wilson#441: CFC's are indeed greenhouse gases, but measured in parts per trillion, they don't do much. As the figure shows, CO2 and CH4 are the big kahunas of GHGs.
  25. The End of the Hothouse
    Causation is a fundamental tenet in science. True randomness is very hard to find. Even what is called "unforced variation" still happen because of causes. These are of fundamental importance to say weather-forecasters or ocean dynamic modellers but not so much for climate since they are energy-bound. For CO2 drop, you cannot simply expect CO2 to disappear. A process must be operating that takes it from atmosphere and changes one or more the carbon-cycle fluxes. These are all governed by physical and chemical laws. You can believe in magic but I find science more useful. Obligatory XKCD
  26. Foster and Rahmstorf Measure the Global Warming Signal
    Sorry, wrong link for Sato et al., 1993.
  27. Foster and Rahmstorf Measure the Global Warming Signal
    #73 skept.fr: "So, if I correctly understand the methods, the AOD measure is not limited to volcanic activity signal, but to all aerosol's changes including the anthropogenic sources." I may be wrong, but what I understand from this study is that AOD here stands for stratospheric AOD, which really is a measure limited to volcanic activity signal, and which influence used in FR2011 seems detailed in Lean&Rind 2008 (finally the equivalent study with the same exogenous factors, but in the opposite path) : "Volcanic aerosols in the stratosphere are compiled by [Sato et al., 1993] since 1850, updated from giss.nasa.gov to 1999 and extended to the present with zero values." Moreover, the study result of FR2011 called "true global warming signal" corresponds to an estimate of the net anthropogenic forcing : "including greenhouse gases, landuse and snow albedo changes, and (admittedly uncertain) tropospheric aerosols." Just to be sure to agree on the fact that it doesn't represent the filtered GHG global warming signal, but the whole AGW signal.
  28. Models are unreliable
    JamesWilson - "CFCs are also much more of a GHG than CO2. Lending them actually higher credibility" Higher credibility with whom? Random bloggers on the internet? CO2 is a powerful greenhouse gas. Note the relationship between CO2 and global temperature from the ice cores: Because of fossil-fuel burning (mainly) atmospheric CO2 is now at its highest concentration in at least 15-20 million years. See Tripati (2009). The satellites also observe CO2 trapping more heat. See SkS post: How do we know more CO2 is causing warming? And finally, CFC's are discussed in this SkS post: It's CFCs The heat-trapping ability of CO2 does not simply disappear because man-made chemicals can also trap a small amount of heat. And if you wish to comment further on CFC's, do so on that thread. Thanks.
  29. Models are unreliable
    The Graph of Sea Levels according to Jason 2 is out of date. This is the Nasa site. Oddly the Jason-2 site shows the change and drop starting in 2010 but I can't find a link to that at the moment. http://climate.nasa.gov/keyIndicators/
  30. Models are unreliable
    "Noone has created a general circulation model that can explain climate's behaviour over the past century without CO2 warming." This isn't true regardless of the veracity of Qing-Bin Lu's claim that CFCs actually more closely model Global Warming trends than CO2: It is a model that shows the trend without using CO2 as the driver. CFCs are also much more of a GHG than CO2. Lending them actually higher credibility as the driver of Global Warming. From a scientific perspective you need much less of them to cause a problem.
  31. The End of the Hothouse
    @ doubtingallofit
    "The moderator response to "The level of CO2 drops for no particular reason" was that this is positing magic. It is unclear how magic and lack of a particular reason are equal."
    CO2 does not rise nor fall without causative physical reasons/mechanisms. To posit that it simply "drops for no particular reason" is to betray either a lack of knowledge about those physical, causal mechanisms (unfortunately for TIS, he is very aware of those mechanisms but conveniently omits them) or to just make a comment that is intended to waste the time of others. I.e., trolling. For more info on CO2, I recommend watching this video on why CO2 is the biggest climate control knob in Earth's history.
  32. The End of the Hothouse
    What the moderator is saying is that there will always be a reason for drop in CO2 - the idea that something happens without a cause is in fact magical thinking. Moreover, particularly large changes of the sort referred to can only be caused by a limited number of mechanisms, which we understand very well. In many cases we know enough to determine if those mechanisms could or couldn't be acting. I don't see how your cancer cluster example is relevant. That is simply a case of being properly rigorous in statistical analyses of data so that we don't try to explain a phenomenon that does not actually exist. Such false phenomena can actually happen for no particular reason, because they are a figment of our imagination. While quantum mechanics seems magical to the unitiated, it has proven to be very predictive - so it classifies as a particular reason for lot of stuff that happens. It would be magical thinking if we concluded instead that the phenomena explained by quantum mechanics happened for no particular reason.
  33. Foster and Rahmstorf Measure the Global Warming Signal
    skept.fr#73: "aerosols have been decreasing in the 1980s and 1990s" Numbers are always nicer than 'probablies' and 'summaries.' Here are some from Hatzianastassiou et al, as presented at 2009 EGU: On a global basis ... the AOT has slightly increased (by about 4%) over the two-decadal study period, mainly in the Southern Hemisphere. Consequently, the magnitude of aerosol DREsurf has also increased by 0.38±0.1 W m-2 (or by 6%) indicating thus an aerosol solar dimming from 1984 to 2001. ... Although on a global basis the contribution of aerosols to GDB can be exceeded by the effects of other radiative components such as clouds, aerosols are found to significantly contribute to GDB at the regional scale Here AOT = aerosol optical thickness, GDB= global dimming and brightening, DREsurf = direct radiative effect on solar radiation at the Earth's surface The problem will be in the last sentence of the quote: these effects are regional. How do you propose to include that in an analysis such as FR2011, which is a decomposition of temperature record into components and not a forward model?
  34. doubtingallofit at 04:48 AM on 24 December 2011
    The End of the Hothouse
    #23 The moderator response to "The level of CO2 drops for no particular reason" was that this is positing magic. It is unclear how magic and lack of a particular reason are equal. Isn't this how we get statistical anomalies entrenched as the truth? For example, cancer clusters that aren't real? A whole lot of quantum physics seems pretty magical, so would that not be science? Please clarify how magic and no particular reason are the same.
  35. Updating the Climate Big Picture
    John Brookes @17 & 18, globally averaged it is 6 *10^-6 W/m^2, so no. Specifically with regard to ocean heat content, that measured in units of 10^22 Joules for convenience for the upper 700 meters.
  36. Foster and Rahmstorf Measure the Global Warming Signal
    #71 Bob : thank you. So, if I correctly understand the methods, the AOD measure is not limited to volcanic activity signal, but to all aerosol's changes including the anthropogenic sources. Furthermore, the direct effect (reflectance in clear sky) can be accurately estimated, but not the indirect effects of aerosols (total cloudiness and optical property of clouds). If this a correct, FR2011 probably underestimate the trend (or the slope of the warming signal). As mentioned in 57, it is widely considered in the literature (see this 2009 review for example) that aerosols have been decreasing in the 1980s and 1990s (warming trend, not fully accounted in FR2011 for the indirect effects by AOD) then stabilizing and slightly increasing in the 2000s (cooling trend with same problem, not fully accounted for the indirect effects by AOD). So, it suggests a full account of aerosols would likely produced a higher warming signal in 2000s than in previous decades.
  37. Updating the Climate Big Picture
    Believe me, Daniel Bailey, it was there in the original post.
    Response:

    [dana1981] Oh yeah sorry, I just went ahead and made the suggested change.  Probably should have made a note - it's been a busy day.

  38. Updating the Climate Big Picture
    Sorry - 10^17 Joules, not 10^20.
  39. Updating the Climate Big Picture
    A quick question. Looking at sea levels from 2010 to 2011 shows a drop of ~8mm. Assuming that all this water ends up on land at an average elevation of ~5m gives this water a raise in potential energy of ~ 10^17 Joules. This energy will be converted back to heat as the water returns to the sea. Is 10^20 Joules a significant amount of energy in the atmosphere - upper ocean system?
  40. Roy Spencer on Climate Sensitivity - Again
    Tom, I used table 2 from my link in #62 which says "Jan 1979–Dec 1998" so I went through Dec for the trend from woodfromtrees. There are other problems with this method such as the basic difficulty of estimating what the effect of the old errors would be on new trends. Would their estimate in 2011 be only 1/4 of the actual trend today if they had not made the 1998 and subsequent corrections? Can't say for sure.
  41. Roy Spencer on Climate Sensitivity - Again
    Eric (skeptic) @62, I considered using that method, but to do so correctly you must ensure the trends are taken over the same period, to the month. As Spencer and Christy do not always state the final month in the trends in various publications, that is not always convenient. It is not clear to me that you have done that, particularly with the 1998 date (which was published in 1998 but may have included no data later than 1997).
  42. Updating the Climate Big Picture
    To show how even more unreliable is your source, I show how the piece I linked before ends: "U.S. Economy at a Crossroads: Ironically, the communist nation of China is making energy decisions based on capitalist principles , while the United States of America is floundering with a non-energy policy that most closely resembles a variation of European Socialism ." This page has also the following intro: "This page contains facts and figures about U.S. coal resources that every American should know. If you dislike America or capitalism you should not read this page. Go instead to this page: http://www.greensocialist.org.uk/ags/" (a british socialist page called Alliance for Green Socialism) This statements that want to accuse proponents of action against climate change of being politically biased towards socialism and communism are likely an example of projection: a trasfer the sub-conscient sense of guilt to your adversary. (-Snip-)
    Response:

    [DB] Please refrain from remarks about politics and ideology (snipped).

  43. Updating the Climate Big Picture
    Mr mace: You should be careful with the sources of information you use. Your source is called "Plant Fossils from West Virginia" (http://www.geocraft.com/WVFossils/Articles1.html) This innocent-looking site do not just question the science of global warming. It also has this section: "America has the Worlds Largest Coal Supply" where, in a few words, the following is sustained: 1:America is the "Saudi Arabia" of Coal 2:The Petroleum Dilemma 3:Coal is the Key to Affordable Energy 4:China Chooses Coal 5:Renewable Energy Requires Coal 6:Liquid Fuels from Coal 7:U.S. Economy at a Crossroads It a series of half-truths that fall in one category of writing: propaganda. This shows that whoever wrote this page is on the side of the most dirty fossil fuel industry: coal. Obviously this is not a reliable source.
  44. Updating the Climate Big Picture
    GrahamC, the term 'conclusively prove' appears nowhere in the above article.
  45. Roy Spencer on Climate Sensitivity - Again
    A simple estimate of the corrections is to use current UAH data with up-to-date corrections and compare the trend for an early part of the data to the trend calculated in an old paper with uncorrected or less corrected data. The corrected trend for Jan1979 to Apr2002 is 0.26C or 0.11C per decade, see http://woodfortrees.org/plot/uah/from:1979.0/to:2002.33/plot/uah/from:1979.0/to:2002.33/trend The corresponding trend from the paper in Tom's post 51 above is 0.06C per decade. So about one half of the corrected trend for that period is from corrections and the other half is from warming over that interval. Looking back a little farther, there is 0.23 trend from 1979 through 1998 or 0.115 per decade in current corrected data. The corresponding paper http://journals.ametsoc.org/doi/pdf/10.1175/1520-0426(2000)017%3C1153%3AMTTDCA%3E2.0.CO%3B2 indicates a 0.03 per decade trend corrected to a 0.06 per decade trend (+/- 0.06). Although the "peak" in their underestimate of TLT trend may have occurred earlier than 1998, the correction made at that point seems to be the most significant in magnitude (comparing the error in the trend to the trend itself). Also the comparison above does not mean that the current corrections are complete.
  46. Updating the Climate Big Picture
    This is a great article. Just one niggle. Would you consider replacing the term 'conclusively prove' (in the Humans are Increasing Atmospheric Greenhouse Gases section) with something else? Lots of the non-scientists who resd this will interpret that as implying 100% certainty, and seeing the term used here makes them susceptible to the skeptics demand that they shouldn't believe anything unless it's 'proven'.
  47. Updating the Climate Big Picture
    mace, The geocraft CO2 history has been debunked many times. See this CO2 was higher in the past thread. Once again, the best advice is to read and learn, rather than make decisions from unsubstantiated claims.
  48. Bert from Eltham at 10:46 AM on 23 December 2011
    Foster and Rahmstorf Measure the Global Warming Signal
    Yes Tom Curtis I am sorry if I went off half cocked. I fully realize it is not helpful. I am just an older retired Physicist and we are used to being correct! skept.fr is at least logical and his analysis is sound if his assumptions are real. The real problem I have is that full picture is difficult to comprehend. Flying a light aircraft solely on instruments is something you all should try. If you do not cross correlate all the information or rely on one instrument indication you will crash. We are all biased by our life histories. None of us is immune. Again I will think more carefully before posting next time. Bert
  49. Updating the Climate Big Picture
    "I think what's clear is that mother earth's been around billions of years, and we need at least 50,000 years to see the signal emerge from the climate noise." Nope. The temperature signal shows two things: 1/ internal variability (eg ENSO) which is unforced variation due to distributing heat around a water-covered planet. 30 years appears to more than enough time to account for this. 2/ forced variability from natural forcings (eg sun (milankovitch and solar output variation), volcanic aerosols; and longer time scales - variation from continent arrangement and GHG variation due to biochemical factors. To claim that you need a longer time to sort natural from anthropogenic would require some evidence that there is natural variation that is not yet linked to a natural forcing. As it stands - no evidence that I am aware of. We can account for past variation from past forcings and we know the strength of current forcings. Natural forcing alone do not account for current climate (eg Meehl 2005 or the summary in the IPCC report). Furthermore, there needs to some magic that counteract the effect of the known physics of GHGs. So far the modelled effect of increased GHG is being reflected the observations. Ignoring that and praying for some natural variation fairy to let us off the hook is imprudent to me.
  50. Updating the Climate Big Picture
    4, mace, That's a wonderful find!!!! You should now look and see how the site you posted absolutely, undeniably and maliciously tricked you and anyone else who visits it. Concerning the "modern temperature record" they used, the recent temps (1979-2001) are supposedly from "Satellite stratospheric data," but since stratospheric temperatures (a) are not in any way indicative of surface temperatures and (b) have been cooling for the last 30 years (in accordance with GHG theory expectations), I think they really meant "tropospheric temperatures." Beyond this, however, if you compare the different measures, you'll find that comparing ground temperatures to tropospheric temperatures is apples and oranges. Concerning the temperature data from 1871 to 1979, why in the world did they use Southern Hemisphere data, of all possible global data sources? One has to scratch one's head at that choice. They may argue that it is similar to the Vostok ice core data (by at least being in the same hemisphere), but that sort of points out how wrong it is to compare any of that to the global mean satellite data. Concerning the temperature data from 1871 back... the temperatures at the poles change substantially more than the global mean temperature. This was true then and it's true now. It's called polar amplification. But the temperature swing in the Vostok data before 1871 is less than 2 degrees from the mean. The temperature swing today at the South Pole is more than 3. At the North Pole it's more than 4.5. So... they used three wildly disparate sources that show entirely different things that can't be compared, in particular a comparison of temperatures at one specific, extreme location in the past (one everyone knows will show more variation) as compared to the global mean temperature in the present (using a metric that everyone knows will show less variation in comparison, and yet it is by far the more important and more sensitive number). Quite a wonderful load of denial misrepresentation you've found! And let it be a lesson to you. Look into the data, and understand what you are looking at, before you accept what they are trying to sell you.

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