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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 109401 to 109450:

  1. Global warming and the unstoppable 1500 year cycle
    Answering #4, Daved Green- The problem here is not so much that being basic, it lacks detail, but rather, that the logical flow of the article is jerky and scattered, and the wording fatally imprecise. Under such circumstances, since, as #3 points out, "'Skeptics' use bits of science like flack to deflect focus from their core arguments", they latch on to each one of these shortcomings and do exactly that -- with gusto and great effect. As an example of the jerky flow, consider even the very first sentence. It announces that there are two things 'interesting'. Then it immediately lists them. But frankly, from that list, neither one sounds 'interesting'. So already the logical flow most plausibly promised by the opening sentence has been lost. But then the article switches to the 1500 year cycle itself. This switch is quite abrupt, since we STILL haven't seen anything 'interesting' in the "two things interesting". But here too, we fail to keep the logical flow: for the unfortunate phrase "global temperature see-saw effect" spoils the whole paragraph. How so? Because the phrase "global temperature" would most logically mean a -single- temperature, which in turn would most likely be an -average- temperature. But the 'see-saw' described must be rising temperature in one hemisphere, while the temperature falls in the other (and vice versa). At best, this would be an example of the rhetorical effect known as 'paraproskokian', since the expected meaning of the word turns out not to be ther right one. But as Wikipedia points out, paraprosdokiam "is frequently used for humorous or dramatic effect, sometimes producing an anticlimax" -- none of which fits here. (See http://en.wikipedia.org/wiki/Paraprosdokian). Frankly, if I wasn't already convinced of the basic truth of the AGW hypothesis, this article would not have convinced me either. It would not even have convinced me to research it further -- especially since it contains no references for its highly contentious claims. BTW: that final contentious conclusion is another example of fatal imprecision in wording: what is being "recorded all around the world" is NOT "the current temperature increase caused by CO2". What is being recorded is merely "the current temperature increase". How much of it is caused by CO2 is exactly the bone of contention (assuming that no one still doubts the accuracy of the measurement -- although you know that because of 'Climategate' they do doubt it). You only give skeptics excuses for disbelief when you misstate it that badly. Unsupported statements of the central thesis (here that CO2-caused temperature rise is already being recorded) belong in the proem, the statement or perhaps on the conclusion, but ONLY when the support has been provided in (the body of) the argument. But where IS it? It just isn't there. Without it, you have no rebuttal at all.
  2. Climate sensitivity is low
    Dana, over at Climate Progress you wrote:
    I should mention, the 'Climate sensitivity' is not specific to CO2′ section isn't quite correct because different forcings have different efficacies. I updated the advanced version of this rebuttal to clarify this point. Here's the link if you want to do the same: http://www.skepticalscience.com/climate-sensitivity-advanced.htm
    I was trying to respond to that, but too many links has put my post in the could-be-spam queue, so I thought I might post this here as well in the hope that some might find it helpful. Definition of Radiative Forcing:
    The definition of RF from the TAR and earlier IPCC assessment reports is retained. Ramaswamy et al. (2001) define it as 'the change in net (down minus up) irradiance (solar plus longwave; in W m^–2) at the tropopause after allowing for stratospheric temperatures to readjust to radiative equilibrium, but with surface and tropospheric temperatures and state held fixed at the unperturbed values'. 2.2 Concept of Radiative Forcing http://www.ipcc.ch/publications_and_data/ar4/wg1/en/ch2s2-2.html
    The idea here is that increased solar radiance or increases in CO2 concentration affect the balance of radiation entering/leaving the climate system -- and will result in a response at the "top of the atmosphere" or - tos - which is typically taken to be at the tropopause which separates the troposphere and the stratosphere. Feedbacks are in response to this change. Definition of Climate Sensitivity:
    The long-term change in surface air temperature following a doubling of carbon dioxide (referred to as the climate sensitivity) is generally used as a benchmark to compare models. Climate Change 1992 The Supplementary Report to the IPCC Scientific Assessment, pg. 16 http://www.ipcc.ch/ipccreports/far/IPCC_Suppl_Report_1992_wg_I/ipcc_far_wg_I_suppl_material_full_report.pdf
    The above definition of climate sensitivity is however for the Charney Climate Sensitivity that takes into account the fast feedbacks, e.g., water vapor, clouds, sea ice, etc., but omits the slow feedbacks associated with changes in vegitation, feedbacks due to the carbon cycle and ice sheets -- the latter of which are land-based. Definition of Efficacy:
    Efficacy (E) is defined as the ratio of the climate sensitivity parameter for a given forcing agent (λi) to the climate sensitivity parameter for CO2 changes, that is, Ei = λi / λCO2 (Joshi et al., 2003; Hansen and Nazarenko, 2004). Efficacy can then be used to define an effective RF (= Ei RFi) (Joshi et al., 2003; Hansen et al., 2005). For the effective RF, the climate sensitivity parameter is independent of the mechanism, so comparing this forcing is equivalent to comparing the equilibrium global mean surface temperature change. 2.8.5 Efficacy and Effective Radiative Forcing http://www.ipcc.ch/publications_and_data/ar4/wg1/en/ch2s2-8-5.html
    Why Efficacies of Different Forcings are Different:
    The efficacy primarily depends on the spatial structure of the forcings and the way they project onto the various different feedback mechanisms (Boer and Yu, 2003b). Therefore, different patterns of RF and any nonlinearities in the forcing response relationship affects the efficacy (Boer and Yu, 2003b; Joshi et al., 2003; Hansen et al., 2005; Stuber et al., 2005; Sokolov, 2006). Many of the studies presented in Figure 2.19 find that both the geographical and vertical distribution of the forcing can have the most significant effect on efficacy (in particular see Boer and Yu, 2003b; Joshi et al., 2003; Stuber et al., 2005; Sokolov, 2006)... 2.8.5.1 Generic Understanding http://www.ipcc.ch/publications_and_data/ar4/wg1/en/ch2s2-8-5-1.html
    For more on radiative forcing and related concepts please see: Chapter 2: Changes in Atmospheric Constituents and in Radiative Forcing http://www.ipcc.ch/publications_and_data/ar4/wg1/en/ch2.html Note: calculations performed by climate models do not involve the concepts of forcing, climate sensitivity or efficacy. The calculations of climate models are themselves based up the physics. Analysis in terms of forcings, climate sensitivity and efficacy only come afterward -- as a means of conceptualizing the results for the ease of our understanding.
  3. Should The Earth Be Cooling?
    No worry's Daniel-- I also make the same mistake from time-to-time. My comment/clarification was mostly directed at "skeptics".
  4. Should The Earth Be Cooling?
    Re: Albatross (60) Thanks for the reminder. :) I was a little fired up & used KL's quote back in the context he meant it (the non-science, or layman's everyday usage). I should probably have corrected that misunderstanding as well. But it's difficult to catch everything in a comment like that because of the sheer amount of misunderstandings going on. I will try to exercise more judiciousness in my words. BTW, the NAS definition you cite is very similar to the NAS statement in May on global warming:
    " A strong, credible body of scientific evidence shows that climate change is occurring, is caused largely by human activities, and poses significant risks for a broad range of human and natural systems…. Some scientific conclusions or theories have been so thoroughly examined and tested, and supported by so many independent observations and results, that their likelihood of subsequently being found to be wrong is vanishingly small. Such conclusions and theories are then regarded as settled facts. This is the case for the conclusions that the Earth system is warming and that much of this warming is very likely due to human activities."
     Source here. Thanks again, The Yooper
  5. Climate sensitivity is low
    From the main article:
    A 2008 study led by James Hansen found that climate sensitivity to "fast feedback processes" is 3°C, but when accounting for longer-term feedbacks (such as ice sheet disintegration, vegetation migration, and greenhouse gas release from soils, tundra or ocean), if atmospheric CO2 remains at the doubled level, the sensitivity increases to 6°C based on paleoclimatic (historical climate) data.
    Hansen et al estimate Earth System Sensitivity (ESS - that includes slow feedbacks) over Charney Sensitivity (CS - that only includes fast feedbacks) - or ESS/CS - at 2:
    Paleoclimate data permit evaluation of long-term sensitivity to specified GHG change. We assume only that, to first order, the area of ice is a function of global temperature. Plotting GHG forcing [7] from ice core data [18] against temperature shows that global climate sensitivity including the slow surface albedo feedback is 1.5°C per W/m 2 or 6°C for doubled CO2 (Fig. 2), twice as large as the Charney fastfeedback sensitivity. Note that we assume the area of ice and snow on the planet to be predominately dependent on global temperature, but some changes of regional ice sheet properties occur as part of the Earth orbital climate forcing (see Supplementary Material). pg. 220, James Hansen et al.(2008) Target Atmospheric CO2: Where Should Humanity Aim?,The Open Atmospheric Science Journal, 2, pp. 217-31 http://pubs.giss.nasa.gov/docs/2008/2008_Hansen_etal.pdf
    A more recent estimate puts ESS/CS at about 1.4:
    As shown in Table 1, none of these assumptions greatly changes our estimate of ESS/CSacross all of the analyses presented in this article, the smallest value of ESS/CS we obtain is 1.3, and the largest is 1.5. Our combined modelling and data approach results in a smaller response (ESS/CS~ 1.4) than has recently been estimated using palaeo data from the Last Glacial Maximum, 21,000 years ago (ESS/CS ~ 2). This is probably due to the fact that transitions from glacial to interglacial conditions in the Quaternary involve large changes in the Laurentide and Eurasian ice sheets (see, for example, ref. 36), which result in a significant large-scale albedo feedback in these regions that is irrelevant for climates warmer that present. pg. 63, Daniel J. Lunt et al. (January 2010) Earth system sensitivity inferred from Pliocene modelling and data, Nature Geoscience, Vol. 3
    Either way the climate sensitivity that people have been talking about underestimates the warming that we can expect because by definition it omits the slow feedbacks -- which aren't necessarily that slow (e.g., the reduction in plant efficiency over the past decade, the saturation of some ocean CO2 sinks, Boreal forests in Canada, rising levels of methane emissions due to permafrost melt in Arctic tundra and Arctic shallow water continental shelves, e.g., near the coastline of Siberia.
  6. Climate change: Water vapor makes for a wet argument
    johnd #138: "Is it absolutely certain that natural CO2 emissions are not rising faster than offsetting natural sinks in response to increased temperature?" Yes. Yes it is. We know that the steady increase of atmospheric CO2 (and ocean carbonic acid) over the past century has been due to human emissions. See 'empirical evidence that humans are causing Global warming'. Besides, how can you really think that warming is causing the CO2 rise when the CO2 has been increasing steadily while warming has undergone numerous significant fluctuations... no correlation.
  7. Should The Earth Be Cooling?
    Daniel @58. Thanks for calling Ken on his misinformation @56. Just one nit pick, one has to be careful about distinguishing between a "hypothesis" and a "theory". Many people, it seems, try to discredit or belittle the physics behind AGW by referring to it as a "only a theory", when, if that is their intent, they should be referring to the "hypothesis of AGW". The increased radiative forcing from elevated GHGs is a well established and tested theory. In the science world, a "theory" carries a lot more weight than a "hypothesis". "According to the United States National Academy of Sciences, Some scientific explanations are so well established that no new evidence is likely to alter them. The explanation becomes a scientific theory. In everyday language a theory means a hunch or speculation. Not so in science. In science, the word theory refers to a comprehensive explanation of an important feature of nature supported by facts gathered over time." [source, Wikipedia]
  8. What were climate scientists predicting in the 1970s?
    Another oldie, but a goodie: Bolin and Bischof, 1970 Variations of the carbon dioxide content of the atmosphere in the northern hemisphere Six years of measurements (1963-1968) of carbon dioxide in the troposphere and the lower stratosphere are presented. The data reveal an average annual increase of the CO2 content of 0.7 +/- 0.l ppm/year, while during this time the annual industrial output has increased from about 1.9 ppm to 2.3 ppm/year. ... Accepting 35% as being the most likely net increase in the atmosphere as compared with the total output yields 332 ppm for 1980 and 371-378 ppm for year 2000 if using the values for CO, output based on the OECD estimates. And the 2000 annual CO2 average was: 369.4ppm
  9. Should The Earth Be Cooling?
    KL #56 "Some facts please kdkd" Facts: If I (or any other capable person) were to do the statistics examining the linear trends, the cherry picking you've done by eyeball would be a trend that I'm 99.99% sure would be shown to be statistically indistinguishable from zero. Which in turn doesn't mean no warming or cooling, it means that there's insufficient data to determine the trend on that time scale. I stand by my previous comment that your position is illogical, incorrect, and theoretically unsupportable repetitious rubbish. Is that a sufficiently factual for you?
  10. Climate change: Water vapor makes for a wet argument
    Also, the "dismissing" of BOM data because was because it measured what was important to agriculture, every seen it is perfectly well understood and explicable from known physics but it did not measure the variables necessary for investigating water vapour/radiation relationships. Also your continuing insistence on understanding carbon cycle is interesting. AR4 models do not on the whole include carbon cycle at all - because it assumed to be a slow feedback. The understanding of what part of our emissions remains in atmosphere is from measurement again. This is looking for excuses not looking for truth.
  11. Climate change: Water vapor makes for a wet argument
    Johnd - "not understood" - simply not true. We MEASURE all this stuff. You are looking for microscopic local changes and inferring this can drive large scale global trends while at the same time arguing that the MEASURED increase in backradiation from greenhouse gas - a much larger forcing - is insignificant. I am sorry but you seem to engaged in wishful thinking only. I have wasted enough time trying to explain. I'm out of here.
  12. Climate change: Water vapor makes for a wet argument
    johnd at 06:37 AM, correction, that should read "If that is the case what are the limits that any imbalance reaches either side of balanced before the natural PROCESSES adjust to overcome imbalances over or under?"
  13. Climate change: Water vapor makes for a wet argument
    Bibliovermis at 06:10 AM, the point being made is that until complete understanding is reached about what drives the natural sources, and sinks that are able to accommodate seasonal variations many times the total amount of human emissions, then there are many assumptions having to be made. One could be that the natural cycles adjusts to seek a balance. If that is the case what are the limits that any imbalance reaches either side of balanced before the natural balances adjust to overcome imbalances over or under? Are the responses linear or do they progressively ramp up, or down responding to the degree of imbalance? Is it absolutely certain that natural CO2 emissions are not rising faster than offsetting natural sinks in response to increased temperature?
  14. Climate change: Water vapor makes for a wet argument
    human [CO2] emissions are tiny by comparison, 1/30th
    Johnd, that is a sophistic partial truth which is arrived at by focusing on one side of a natural cycle rather than considering the net amount. It has already been addressed on this site. How do human CO2 emissions compare to natural CO2 emissions? (argument #28)
    The natural cycle adds and removes CO2 to keep a balance; humans add extra CO2 without removing any.
  15. Climate change: Water vapor makes for a wet argument
    KR at 02:47 AM, you wrote "the fact that the primary IR emissions to space from water vapor come from above the cloud layers" Can you clarify that as I'm not sure what you mean, given that as water vapour rises it progressively gives up it's heat, condensing into clouds, the last of the heat being given up by whatever is remaining of the water vapour, obviously, at the level of which the highest clouds form.
  16. Climate change: Water vapor makes for a wet argument
    I think the point being missed with regards to both water vapour, the subject of this thread, and CO2 is whilst the effects may be felt in the upper atmosphere, the causes of water vapour, evaporation, and of the natural releases of CO2, human emissions are tiny by comparison, 1/30th, all are due to conditions that prevail in the micro-climate that exists at the earths very surface, both over land and the oceans. As I pointed out earlier, those whose interest lies in what happens within that micro-climate find conditions somewhat different to those whose interest begins with data collected 1.2m above ground level, and it will be such that as understanding of the processes that occur within that micro-climate improve, the causes, that will feed into providing greater understanding of the macro-climate, and the effects. I think the way in which the BOM data I referred to was generally dismissed because it was deemed to be for agricultural purposes is indicative of the lack of appreciation of just how important understanding the processes of the micro-climate is to the overall understanding of the climate generally, and the weather systems which ultimately define what the climate is at any given point of time.
  17. Climate change: Water vapor makes for a wet argument
    Re: KR (132) I was a little lazy in my previous linked graphic (it was a little dated, being from 2003). The AIRS site has more up-to-date graphics, like this one from 2009: I note in passing that Bermuda is still a world-leader in emissions. :) The Yooper
  18. The contradictory nature of global warming skepticism
    @Baz: "Where’s the heat, CBD, where’s the heat?" It's here, Baz, it's here!
  19. The contradictory nature of global warming skepticism
    @Baz: "because I've witnessed 10 years of flat HadCRUt data" The HadCRUt data isn't flat, no matter how much you claim it is. Stop repeating this false statement, or we won't have any other choice but to consider you a liar. "You may well point to other metrics as evidence, and that may be valid, but after all is said and done, I am sceptical that the future will be warm - based on those 10 years and the fact that we know so little about climate science." We know enough to say that the last 10 years aren't statistically significant. "Now that may well be illogical to you, even irrational. That's fine, I can live with that," So, you admit you're wrong, but you'd rather be wrong that accept the science? What are you doing on this web site, then? "but you have to understand that people like me, who hover on the fence, and who will be swayed by a few year's worth of data, are the norm, the mainstream." You're not, actually. Most people worldwide believe the warming is real, and that humans are responsible. Even if you were right (which you aren't), the argument still wouldn't make sense. It's like saying "most people believe the Earth is flat, so it's okay if I believe this as well, even though I've been presented with evidence to the contrary." "You're not going to change our view by pointing us to climate metrics that are still disputed by very eminent people." Which climate metrics are disputed by which very eminent people? Asking for a twenty year (or even 15) years period for statistical significance isn't controversial. "Let's be honest with each other, if ALL the scientists were on one side then to believe the opposite would be pretty obtuse." 97% isn't enough for you? Let's be honest with each other (and I don't care what you think, since you'll no longer respond to me): you have admitted yourself to not being rational, i.e. you will not accept any rational argument that goes against your unscientific opinion. No wonder you trust contrarians like Spencer and the Pielkes - they reinforce your belief, so you accept what they say wihout question. You've made it clear you have no credibility on this matter, and that you're only interested in spreading FUD. Please stop wasting our time.
  20. It's cosmic rays
    Regarding Duplissy et al. 2010 Results from the CERN pilot CLOUD experiment on their preliminary results, please see this comment on a different thread and make any subsequent comments here.
    Moderator Response: Thanks for helping keep the threads organized!
  21. The contradictory nature of global warming skepticism
    Baz... How can you state in one moment that 1995-2009 is 0.12C/decade but is "not statistically significant" while at the same time telling us that flatting temps from 2002 to 2010 is somehow this problem for global warming?
  22. Climate change: Water vapor makes for a wet argument
    johnd - CBDunkerson is quite right; small variations at ground level (to the extent there are any) will have insignificant effects on global warming. AGW is driven by radiative imbalances, which occur in the upper troposphere - the more GHG's present, the higher the emission mean for IR in the atmosphere, and the warmer the planet has to be to reach radiative balance. The cooling air at ground level is part and parcel of the "radiation fog" effect - a completely understood phenomena. That's a red herring in regards to climate change, quite frankly, and is no longer worth discussing. Water vapor has its primary effect in the upper troposphere as well - I can't find the link right now, but the fact that the primary IR emissions to space from water vapor come from above the cloud layers is why fairly simple average values are of use in global climate models. Clouds (lower in the atmosphere) do have an effect, but at a level where the consensus isn't certain whether it's net positive or net negative feedback - that's where most of the +/-1.5C in feedback for CO2 doubling comes from.
  23. Climate change: Water vapor makes for a wet argument
    My apologies - the map I posted here is indeed an emissions map (as johnd pointed out), not a concentration map. The appropriate map is the one Danial Bailey posted here. This also more clearly demonstrates the point I was trying (rather badly) to make: that when johnd thought that CO2 concentrations varied significantly with a range of a few meters, he was quite wrong. My apologies if my original post was misleading/incorrect.
  24. The contradictory nature of global warming skepticism
    Baz, so essentially... By carefully cherry picking the start and end points, and/or citing false values for the data, you can come up with a situation where the warming is 'only' 0.12 per decade (i.e. 1.2 C total by 2100 IF we assume no acceleration)... which you can then falsely describe as "flat"... and on that basis you can then falsely say that this is sufficient to 'disprove man made global warming'. Where's the heat? Gee, I dunno... hottest decade in the temperature record; 2000-2009. Second hottest; 1990-1999. Third hottest; 1980-1989. Are we seeing a pattern here? You seem to be arguing that if AGW theory is correct then the temperature would have to increase at a near constant rate... which, of course, is completely contrary to AGW theory. Of course the rate of increase will fluctuate with various other conditions... such as the current prolonged lull in solar activity. As to there having been "no volcanoes" since 1995... absurd on its face. Tell it to all the people who couldn't fly in Europe earlier this year because of the eruption in Iceland. BTW, you're also wrong about CO2 emissions being higher than ever... they actually dropped a bit the past couple of years due to the global recession. Finally, let's compare two of your recent statements; Baz #277: "BTW, I've 'ignored' no other's comments other than yours" When I pointed out that this was false as you'd ignored my comments in #39 and #105 (amongst others) the response was; Baz #290: "BTW, you didn't ask me any questions in 39. I HAVE made an effort to respond to genuine questions." So... you switched from having answered all COMMENTS to having made an effort to respond to QUESTIONS. Except, of course, you didn't respond to my questions in #105 either. You're falling short even when you move the goalposts.
  25. A South American hockey stick
    #43:"the CLOUD experiment " Philippe: Thanks for that link. This is wayyy off topic, but since it came up here: Upon reading the paper, there is some lingering confusion over what they are doing: During selected periods, the chamber was exposed to a 3.5 GeV/c positively-charged pion beam from a secondary target. Pions of this energy correspond closely to the characteristic energies and ionisation densities of cosmic ray muons penetrating the lower troposphere. Minor editorial nit pick: GeV/c is a momentum, not an energy; the energy would be 3.5 GeV. We all make typos. Muon energies range from 6 GeV near the top of the atmosphere to 4 at ground, losing energy to ionization - a process that is continuous. Because of the high flux of muons (~1/cm^2 per minute at the surface -- see link above) due to solar cosmic rays, if muons alone were cloud-formers, we'd live in a sea of clouds. Yet the experiment was designed to study galactic cosmic rays: The present results, while suggestive, are insufficient to unambiguously establish an effect of galactic cosmic rays on cloud condensation nuclei, clouds and climate, ... Experiments are planned for the CLOUD facility at CERN to resolve this deficiency. With GCRs, we typically speak of much higher energies and that was the original pitch for enhanced ionization. Here is a very readable blog post on GCRs. I did a very preliminary analysis of online high energy events from the Auger detector; there is a slight increase in frequency during the sunspot minimum of 2009. Anyone note any increased cloudiness during that time?
    Moderator Response: Everybody who wants to discuss this further, please do so on the thread of the skeptic argument It's Cosmic Rays".
  26. Global warming and the unstoppable 1500 year cycle
    @Tom: "You even quote from the paper saying that the warming barely shows up in the Southern Hemisphere! However, I couldn't read the full paper so you may have something I missed." I couldn't read that paper either, but I got curious and searched for thingadonta's quote ("The pattern in the Southern Hemisphere is different, with slow warming and much smaller temperature fluctuations") on Google. The first result to come up was this very thread (thanks, Google's fast indexing). The second was a Wikipedia article (last revision Sept. 8) on Dansgaard-Oeschger events: http://en.wikipedia.org/wiki/Dansgaard-Oeschger_event#Causes Voelker's paper is cited on that page. Note that D-O events occured during the last *glacial* period, which would render thingadonta's argument nil since we are now in an interglacial, so his example doesn't apply.
  27. A South American hockey stick
    Re: RSVP (37)
    "I went to the link and could only read the abstract without paying for the actual article."
     Link to the full source provided in comment 4 above. The Yooper
  28. Himalayan Glaciers: Wrong Date, Right Message
    In the WG1 report of IPCC AR4, Chapter 4 "Observations: Changes in snow, ice and frozen ground" included a review of the state of glaciers (Cogley was a contributing author there), but not their future outlook. The global summary of future outlook of glaciers is included in Chapter 10 "Global climate projections", in particular section 10.6.3, in the context of sea level change. Glaciers were not discussed in Chapter 11 "Regional climate projections."
  29. Should The Earth Be Cooling?
    Re: Ken Lambert (56)
    "Ned's Chart at post #18 here: http://www.skepticalscience.com/The-Pacific-Decadal-Oscillation-and-global-warming.html shows smoothed GISS land + SST and RSS temperatures which sure looks like flattening over the last 8-10 years. That's if a clear reduction in the slope of a curve is flattening - which for most people it is."
     Are we even looking at the same graphic? The overall trend (1900-2010, 1980-2010) is UP. Perhaps your razor-focus on statistically insignificant timescales blinds you to that fact. Most people would care to be ACCURATE in their statements and assertions and would note that fact. You are WRONG.
    "SLR flattening by nearly all analyses"
     Um, no. Wrong again. Here's what it actually looks like over that interval (from Tamino, reproduced from the University of Colorado site). You mistake natural variations of noisy signals over statistically insignificant timeframes for "flattening" (is that the new meme de jour?). You are CHERRY PICKING. You also make unfounded assertions with NO analysis of your own to support your baseless claims.
    "And all this at a time when the last decade of theoretical CO2GHG forcing 'has been the highest decade' since the last ice age. Sound familiar?"
     There's nothing "theoretical" about the greenhouse gas effects of CO2. It's all reproducible in the lab, and has been since the 1800's. Did you not take science classes in school? You are correct in that CO2 concentrations have been at their highest levels in millennia; the "aughts" are hotter than the 90's, which were hotter than the 80's which were hotter than the 70's, and this year is the hottest year ever (thus far). Note the trend here. You waste all of our time, and that of the readers here as well. Gimme something of substance, some meat and potatoes, to work with here. I'd LOVE for you to be right, but so far you're just statistically significantly "flattening" your credibility. Sound familiar? The Yooper
  30. Philippe Chantreau at 23:42 PM on 19 September 2010
    A South American hockey stick
    I get your point Muoncounter but, still, what matters is how much of a difference in radiative forcing this translates into. These images are also snapshots, how does it average over time? You'd expect concentrations to be slightly higher, as they are observed, near the regions where the most fossil carbon is burned. However, it remains that even very far from these regions the concentrations are not so drastically different that you can't say the CO2 is overall well mixed.
  31. Should The Earth Be Cooling?
    Here's the thing. Over the last 30 years, the planet's been experiencing according to skeptical theory...
    • Cooling from a decline in solar irradiance
    • Cooling from a decline in the PDO
    • Cooling from planetary orbital shifts
    • Cooling from increased cloud cover dervived from cosmic rays
    • Cooling from increased cloud cover from a negative water vapor feedback
    • Cooling from increased cloud cover derived from "biosol" nuclei
    • Cooling from increased cloud cover derived from iodocompounds
    • Cooling from increased cloud cover derived from biologic dimethyl sulfide
    • Cooling from cloud compositional changes derived from the iris effect
    • Cooling from anthropogenic aerosols and soot
    • Cooling from atmospheric aerosols from COS and other natural emissions
    • Cooling from changes to the Meridional Overturning Circulation (MOC)
    And yet temperatures have continued to rise over that time period, and the most that can be claimed is not cooling but a "flattening over the last 8-10 years". If this is the result of so many natural mechanisms opposing the anthropogenic warming signal, what happens when their natural cycles reinforce that signal?
  32. Philippe Chantreau at 23:33 PM on 19 September 2010
    A South American hockey stick
    Ah, HR brings up the CLOUD experiment again. The source for that is Duplissy et al (2010). Available here: http://www.atmos-chem-phys.net/10/1635/2010/acp-10-1635-2010.pdf The experimental design left some to be desired: "The large observed growth rates indicate the presence of additional trace vapours in the aerosol chamber, whose identity is unknown but for which there is indirect evidence of background organic vapours. The presence of background vapours is also inferred from the observation that small (of order 0.1C) increases of temperature invariably trigger nucleation bursts, which is attributed to the release of unknown vapours from the chamber walls." The conclusion is not very, well, conclusive, as in: "However, during most nucleation events, the contribution of ion processes appeared to be minor" End word:"In summary, the exploratory measurements made with a pilot CLOUD experiment at the CERN Proton Synchrotron have validated the basic concept of the experiment, provided valuable technical input for the CLOUD design and instrumentation,and provided, in some of the experiments, suggestive evidence for ion-induced nucleation or ion-ion recombination as sources of aerosol particles from trace sulphuric acid vapour at typical atmospheric concentrations." Since Svensmark was involved in the paper, it is no surprise these words are found, but in fact there is very little there to hang on. Suggestive evidence. I like to be a skeptic too. Suggestive evidence does not impress me much.
  33. The contradictory nature of global warming skepticism
    289. Sorry, that should say, "would give a positive 0.12 c per decade". (which isn't statistically significant)
  34. The contradictory nature of global warming skepticism
    BTW, you didn't ask me any questions in 39. I HAVE made an effort to respond to genuine questions.
  35. The contradictory nature of global warming skepticism
    CBD. I could have chosen 1995 to 2009, which would give a negative 0.12 c per decade. Or I could have chosen the past 10,000 years, or...whatever. Including in a year or few years introduces wildly different per decadel trends, which makes them jump from statistically-significant to insignificant. The past few years have also seen no volcanoes to add any cooling effect. If there had been, then we’d be looking at negative decadel trends. This at a time when CO2 emissions have never been higher. Where’s the heat, CBD, where’s the heat? With no volcanoes the global temp should be ramping up and away. Why isn’t it, CBD?
  36. Global warming and the unstoppable 1500 year cycle
    "The 1500-year cycle in question ": In the discussion of Moberg 2005 in the MWP: Rhetoric vs Science thread, we saw hints of a long period cycle. The amplitude of that cycle appeared to be less than 0.3 degC; the current increase above that cycle is already 0.8 degC -- and climbing. The cycle is broken; thus the skeptic argument based on that cycle is also broken. So to counter broken hockey stick? Broken cycles!
  37. Global warming and the unstoppable 1500 year cycle
    I often see "skeptics" protest saying "hey, no one said the warming is not happening... we're just questioning its cause!" On the other hand, there are no-warming related arguments all around. It's Urban heat island effect, glaciers are not shrinking, Antarctica is gaining ice, the "hiding the decline" email and so on. I never saw a "skeptic" protest in one of those denier blogs and say "Come off it man! We know it's warming!" "Skeptics" are very flexible when they make their arguments.
  38. Should The Earth Be Cooling?
    Daniel Bailey (The Yooper?) and kdkd I will repeat this for you both gentlemen: Ned's Chart at post #18 here: http://www.skepticalscience.com/The-Pacific-Decadal-Oscillation-and-global-warming.html shows smoothed GISS land + SST and RSS temperatures which sure looks like flattening over the last 8-10 years. That's if a clear reduction in the slope of a curve is flattening - which for most people it is. Some facts please kdkd - your derogatory comment can be vented elsewhere - we are trying to keep ad hominem attack out of this blog. Just to repeat some 'multiple independent lines of evidence' - temperature flattening, SLR flattening by nearly all analyses, and OHC flattening or nil by the imperfect but best we have Argo; and Dr Trenberth can only find 60% of the 'missing heat' which has probably gone missing forever. (It has not only left the building - but probably left the planet!) And all this at a time when the last decade of theoretical CO2GHG forcing 'has been the highest decade' since the last ice age. Sound familiar?
  39. Climate change: Water vapor makes for a wet argument
    CBDunkerson at 19:58 PM, for CO2 the carbon cycle starts and finishes at the earths surface. That requires that every 3 to 4 years the equivalent amount of the entire CO2 content of the atmosphere rotates through the various sources and sinks at the surface, passing through those few centimetres both in and out, which is probably where it also either absorbs or releases most of the thermal energy it carries as it circulates. The seasonal variations also show that CO2 levels vary around 20 to 40ppm or even more over the course of the year, remembering that the CO2 released through the burning of fossil fuels is only about 1/30 of that released by natural processes. In addition to the offset in the timing of release and increased sequestration, the location of the sources and sinks may be far apart. If sea surface temperatures are a factor in whether CO2 is being released or sunk, then the circulation and concentration levels may be quite convoluted and as variable, but more difficult to track then say local temperatures, wind speeds and precipitation. Further, given the direct warming effect of CO2 is quite small, and it is the amplifying effect of water vapour that produces most of the greenhouse effect, with the quite large variations in CO2 concentrations throughout the annual cycle, then if water vapour is as sensitive as it is thought, then one would expect the variations in water vapour to respond with even larger amplified responses that then flows through to increased variations in clouds in both volume and distribution.
  40. Global warming and the unstoppable 1500 year cycle
    Thingadonta: "Firstly and generally, you are grouping together and over-simplifying skeptical arguments in order to more easily label and discredit them. This is a common straw man technique." Yes, I agree with this and it annoys me to see it on this site. Although there are a lot of people who deny the warming, my understanding is that most skeptics believe there is a natural warming. Of course, that doesn't stop them from simultaneously saying that Arctic ice has recovered, or that warming stopped in 1998... "Secondly, (nearly all) skeptics do not reject the greenhouse effect. Once again, they disagree about the relative degree and rate." But they might as well reject it entirely, seeing as the end conclusion is that our CO2 emissions don't matter. The "to a relative degree" part of their argument comes across, to me, as just trying to appear more reasonable while still embracing their politically-motivated views on emissions cuts. "You are also wrong about the 1500 cycle being limited to the Northern Hemisphere." Unless I'm misinterpreting the text of the abstract, it seems to contradict what you say about it: "The spatial distribution of all records is biased towards the northern hemisphere, for the marine records especially towards the North Atlantic region. Terrestrial records cluster in western Europe, the western United States, and China." You even quote from the paper saying that the warming barely shows up in the Southern Hemisphere! However, I couldn't read the full paper so you may have something I missed. "Your are also wrong in stating "And unlike natural heat variations the current temperature increase caused by CO2 is being recorded occurring all around the globe – on the ground, in the air and in the oceans." "Natural heat variations" is an awfully vague statement and could refer to a lot of things, but it probably refers to the 1500-year heat variation being discussed here. Which, as I believe you have failed to demonstrate to the contrary, was mainly limited to the Northern Hemisphere. But yes, there are natural warming mechanisms that are global so may the text should be changed slightly. Greenman3610's video on YouTube does a good job at addressing this claim, in fact it may even do by itself instead of this text summary (no offense to John Russell though, he made a good effort):
  41. Global warming and the unstoppable 1500 year cycle
    S. Fred Singer wrote the book on this subject but as we all know, Fred Singer is a lot like George Costanza.
  42. A South American hockey stick
    @31 HumanityRules <"I> About 1/3-1/2 of 20th Century warming is anthropogenic". Another assertion with no sources to back it up.
  43. Global warming and the unstoppable 1500 year cycle
    There's also the simple, it wasn't warming 1500 years ago answer too...
  44. A South American hockey stick
    #29 & #40: Why not go right to the source? click for full scale at source page Change to 'global' 12-31-08 At the time of that image the N/S total variation was indeed about 15 ppm. In the first image in the global data set, 1/1/01, it was only 8 ppm. So the discrepancy between hemispheres has doubled in 9 years? That's no natural cycle. And 15ppm? At 395ppm, the delta F is 1.84; at 380ppm, delta F is 1.63, a difference of 11%. Seems like a lot.
  45. beam me up scotty at 21:41 PM on 19 September 2010
    Should The Earth Be Cooling?
    The arctic is screaming global warming. Skepticism is looking more and more like proselytization. How about this site expanding its scope to include the debate about what we should do about it? Pros and cons of geoengineering Carbon capture State of the art modeling Regional forecasting etc.
  46. What's happening to glaciers globally?
    Riccardo you are correct that just substantial accumulation zone thinning is enough to forecast glacier survival. You want a more sophisticated measure. However, the goal is a simple measure that can be easily applied to all glaciers simply with decent repeat satellite images, or a map and a satellite image. If we make it to sophisticated such as a ratio of thinning to changes in velocity in the accumulation zone we make it difficult to apply. HR good question about the UNEP graph. The WGMS 30 reference glaciers goes back to 1980. Reference network. If they move the start date to 1985 they will be able to expand to up to 45. If they move the start date for the group back to 1946 they will only have 2 to choose from. Only one Storglaciaren in Sweden is in the reference group. In 1949 Sarennes Glacier, France and Storbreen, Norway are added. Thus, the WGMS record for the 1945-1955 period relies on only a couple of glacier and is not useful for a global summary. The graph UNEP has reports only the Storglaciaren data at first, look at Mass Balance Bulletin 10 page 13 for that glaciers graph and compare. Look at page 1-4 for the list of glaciers and years examined, some of the records are not complete from the first to the last year. This is our best mass balance data. There are other glaciers like the Taku Glacier in Alaska where mass balance work began in 1946 that is not part of the WGMS reference glacier system. This is because before this record publishing this record in 1990 I waited for satellite verification of its accuracy. In the section of BAMS state of the Climate 2009-for glacier mass balance-which I authored-we were asked to provide the mass balance data records for previous data periods. Note the WGMS actual reported record, which is absolutely the best, but it only goes back to 1980. WGMS. Before that Cogley who first contacted me about the global glacier mass balance record more than a decade ago, has the best. He has used Geodetic data not just directly measured data. This is data based on volume change determined from repeat mapping, usually via photographs. This work typically does not provide an annual measurement, as annual photographs tend to be rare. It does provide an accurate record for longer time intervals. If you look at Cogley's 2009 Figure 2 you will note that until 1930 and the advent of aerial photography the record is scant. The mass balance record from 1850-1950 will be improved, but Cogley for now has provided the best analysis. There are many more glaciers that we can and will add to a longer term glacier mass balance record since 1950 using geodetic assessment. Think of comparing a glacier today in a satellite image with excellent mapping details to its original mapped state such as for Bear Glacier or Grasshopper Glacier. Is does match the results of Oerlemans (1999) also. That record based on terminus changes is also useful.
  47. It's El Niño
    Please read:http://climatechange1.wordpress.com/2010/08/17/is-enso-rather-than-a-%E2%80%98greenhouse-effect%E2%80%99-the-origin-of-%E2%80%98climate-change%E2%80%99-by-erl-happ/ Tell me this: What is responsible for the long term change in the differential pressure that drives the trade winds and tropical temperature?
  48. Global warming and the unstoppable 1500 year cycle
    I guess this is the problem with some basics versions , its to easy to pick apart becuase it is not detailed enough . Basic versions are just trying to outline an Idea and I think its hard not to generalise otherwise it would become longwinded and hard to give a quick rebuttal while standing on the train .
  49. beam me up scotty at 21:23 PM on 19 September 2010
    Global warming and the unstoppable 1500 year cycle
    "Skeptics" use bits of science like flack to deflect focus from their core arguments. In Thingadonta's case the core argument appears to be absent altogether. The core motive seems clear: impugn the credibility of the author.
  50. The contradictory nature of global warming skepticism
    Baz #287 wrote: "However, as I'm sceptical (because I've witnessed 10 years of flat HadCRUt data)" So you are 'skeptical' based on a false claim. Go figure. What's fascinating is that when you cite the numbers you start from 2001, which was less than ten years ago, round the anomaly values down, and wildly underestimate the 2010 value. The actual numbers are; 2000: 0.271 2001: 0.408 2002: 0.465 2003: 0.475 2004: 0.447 2005: 0.482 2006: 0.425 2007: 0.402 2008: 0.325 2009: 0.441 2010: 0.531 (so far) Drawing a trend line from the start and end points yields; 2000-2009: +0.17 C/decade 2001-2010: +0.123 C/decade Neither seems particularly "flat".

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