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Comments 125651 to 125700:

125651. nofreewind at 12:44 PM on 30 December 2009
        A visual deconstruction of a skeptic argument
        Here is where much of that IPPC AR4 diagram comes from, the first reference. Prentice et al (to keep your website tidy I used a link generator) Look at the big diagram on page 5 developed from tables on page 10. Remember what I said about the Pennsylvania Forests 2004 report, the forest stand size grew 33% in 9 years? Did the IPCC know that, how about the thousands of other different forests in the world that may have responded to CO2 increase and temp increase differently, add to that the rate of vegetation decay and the incalculable ocean temperature gradients, all those are just a start! Unfortunately you didn't deconstruct anything in this post. AND that graph is critical to acceptance of AGW "theory", and it is quite easily deconstructed, even by a complete amateur as myself. But of course, only a very small percentage of even scientific type even know about the Carbon Cycle just take it as face value as accepted consensus, when it is a backward working theory to fit a preconceived model.
125652. nofreewind at 12:27 PM on 30 December 2009
        A visual deconstruction of a skeptic argument
        >The amount of CO2 being absorbed by nature hasn't been a fixed amount in gigatonnes. Instead, it seems to be closer to a fixed percentage (with interannual variability of course). As human emissions increased, the amount of CO2 being absorbed also increased. John, that is all 100% complete "theory". There is no way to prove or disprove that. However, you can easily create a model and work backwords...and make everything fit. We KNOW there has been a global temp increase since 1850. We KNOW that warming oceans release more CO2, whre does that fit in the model? It doesn't have to of course, if you are just creating a model to fit one year in time, like the IPPC AR4. Look at Trends in CO2. CO2 annual growth Maybe just a coincidence, but look at 1998 on right scroll bar. 1998 was the highest CO2 annual growth rate, it also was the large increase in temp, and isn't the El Nino because the oceans release extra heat? Look at 1992, wasn't that a year of crashing global temperatures? 1990-2009 The CO2 growth rate is way down. Certainly man is causing CO2 increase of some sort in the atmosphere, but what about the oceans? Each single degree of ocean temp will have a rate of CO2 exchage, surely I respect the IPCC when they state that that the flux estimations can be off by 20%!!! We only need it to be off by 1 or 2 % in one system and the entire model of man-effect is essentially nonsense. This is something that should be "modeled", but certainly we can't place the entire world in shackles and move our modern society back to the stone age on a theory. Reminds me of 1999! The entire world moved their pensions and savings into the stock market, it seemed like a no loose proposition. Models were created by Harvard geniuses, we couldn't loose. Same with the fancy mortgage derivatives. The common man always looses and my Grandma Susie with her CD.'s, who couldn't even find the business page, was the winner.
        Response: The airborne fraction is calculated from observations, not theory or models. Specifically, it's calculated from the total amount of human CO2 emissions and the measured amount of atmospheric CO2. For more info, see Comparing CO2 emissions to CO2 levels
125653. Jim Eager at 10:08 AM on 30 December 2009
        A visual deconstruction of a skeptic argument
        nofreewind, re 8Gt vs 29Gt, the first is the measure of just the C in CO2 (the more common convention), the second is the measure of the the C plus the O2. In other words, they are the same quantity by different metrics. (Just multiply 8 x 44/12.) Re the apparent contradiction of figures 1 & 2 by 3, you might want to check the work of William Ruddiman. CO2 and CH4 should have been on a downward track ever since the Holocene Climate Optimum of 8000 to 6000 years ago, but instead, both began slowly rising as figure 3 shows. The reason? Ruddiman points out that humans began adding CO2, CH4 and NO2 to the atmosphere when we developed agriculture and that addition really took off with the domestication of rice and the widespread creation of man-made wetlands. Ruddiman also postulates that the absorption of CO2 by reforestation in Europe and then the Americas in the wake of large scale reductions in human populations due to epidemics may have been a factor in the cooling of the Little Ice Age.
125654. nofreewind at 09:40 AM on 30 December 2009
        A visual deconstruction of a skeptic argument
        John, I find your blog to be an authoritative source of sensible AGW arguments, but I don't understand how figure 3 is related to figure 1 & 2. In fact if you look deeper into the issue Figure 3 contradicts Fig 1/2. You come up with 29 Gt of man-made CO2 from fossil/land use change. I am confused, shouldn't that be 6.4 + 1.6 = 8.0 Gt? http://www.ipcc.ch/publications_and_data/ar4/wg1/en/figure-7-3.html This figure shows the scale a little better. http://www.mongabay.com/images/2006/graphs/co2_global_1750-2000.jpg But, nevertheless, the caption states "Gross fluxes generally have uncertainties of more than ±20% ". What that means is the carbon cycle numbers are complete estimates, likely the amt of CO2 from fossil burning is the most accurate of the estimates. Here is deconstruction of your argument in considering the Global Carbon Cycle as something more than an estimate. http://www.nrs.fs.fed.us/pubs/rb/rb_nrs20.pdf slow loader Go to page 19 (22) You will see that Stand-Size of Pa forests increased by 33% btn 1994 and 2005. WOW, that's good, likely helped along because of increased feeding from CO2. This kind of land use change is occurring throughout the entire world. This stand-size increase of 33% likely resulted in enormous changes in CO2 feeding, and more vegetation decay. Scientists should make best estimate guesses to this process, but as stated in the caption, "gross fluxes have uncertainties of +-20%". We know the IPCC states that about 50% of man-made CO2 is taken back in by the oceans/land use, but in reality, that is "working backwards" to fit their models that man is responsible for the measured CO2 increase. It can not be anything but working backwards to fit their climate model of AGW warming and CO2 increase. Then of course, if half of the 8 Gt (or even your 29Gt) is taken by by natural processes, then we have to think, why did CO2 rise when man was putting out only 4Gt or 29Gt? So if the oceans/land behaved in the same way, we would not have had any atmospheric CO2 rise until we reached the 1/2 threshold of where we are today? To read a better explanation of how this is all theory and working backwards I recommend googling, reading and studying, CO2 - The Houdini of Gases. So my interpretation is that if man is making 7 Gt of CO2 now, and nature takes back approx 1/2 or 3.5 Gt, it wasn't until about 1960 that man made 3.5 Gt so there should have been NO RISE in atmospheric CO2 until about 1960. Also, sorry for not formatting links, but is there an easier way to make a link here w/o using html formatting which i find cumbersome?
        Response: Apologies for the confusion - I'm specifically refering to 29 gigatonnes of carbon dioxide. When discussing the carbon cycle, the IPCC use the weight of carbon, not carbon dioxide. I've noticed some depictions of the carbon cycle use carbon, others use carbon dioxide - I decided to use carbon dioxide as I thought it would be less confusing. Bad call! I explain the process of converting carbon weight to carbon dioxide weight here.
        
        The amount of CO2 being absorbed by nature hasn't been a fixed amount in gigatonnes. Instead, it seems to be closer to a fixed percentage (with interannual variability of course). As human emissions increased, the amount of CO2 being absorbed also increased. Figure 7.4 in the IPCC AR4 shows a graph of the fraction of CO2 remaining in the atmosphere (‘airborne fraction’) since 1958 (the thick black line is the 5 year mean). Note that over this period, CO2 emissions have greatly increased:
        
        
125655. Jim Eager at 09:37 AM on 30 December 2009
        A visual deconstruction of a skeptic argument
        Re John's inline comment to RSVP, I think you have the absorbed vs remaining fractions reversed. Shouldn't that be 55% absorbed by the biosphere and ocean, with 45% remaining in the atmosphere? In other words, human emissions of CO2 account for around 220% of the measured increase in atmospheric CO2 -- 100% of the increase, plus another 120% that is absorbed. Or to look at it another way, the biosphere, ocean, and geologic weathering absorb 100% of natural emissions, PLUS 55% of human emissions.
125656. Steve L at 08:27 AM on 30 December 2009
        1998 is not the hottest year on record
        NP @24 -- I haven't looked at the NASA estimates for Angola over the last 27 years. Hopefully you can ask someone who might know why there's a persistent anomaly there, or at least someone who will confirm your finding.
125657. Mizimi at 06:00 AM on 30 December 2009
        Understanding Trenberth's travesty
        #25...a review of Ceres data product can be found here and here "In general, heat storage, solar insolation, and TOA SW reflected flux dominate the systematic errors. Almost all systematic errors appear as planetary heating in the global net balance. Some of the errors like diurnal sampling biases await final confirmation using combined global 1030 Terra, 130 Aqua, as well as 3-hourly and 1-hourly geostationary data sources for SW fluxes, and GERB 30-minute broadband data from METEOSAT for SW and LW flux diurnal cycles. When all errors are combined, CERES Terra SRBAVG Edition2 non-GEO global Net flux is 6.9 Wm-2 versus a predicted range of 1.3 to 6.1 Wm-2. The ERBE-like global net flux is 3.8 Wm-2 versus a predicted range of -3.1 to 1.7 Wm-2. The less accurate ERBE-like global net flux comes closer to zero. The reason, however, is not more accurate TOA fluxes, but fortuitous cancellation of errors of opposite sign. The ultimate goal is of course to get the right answer for the right physical reasons. For example, the improved CERES angular dependence models improve the accuracy of the equator to pole gradient of reflected SW fluxes, especially in polar regions. Now why do I not feel confident about quoted figures for TOA radiation budgets??
125658. NewYorkJ at 04:50 AM on 30 December 2009
        Could CFCs be causing global warming?
        Couldn't the same line of lousy reasoning (not sure how a reviewer could miss that) be used to declare "global temperature has been dominantly controlled by the level of methane...", which rose raipdly through the 80's and 90's and has been mostly flat over the past decade (increasing only recently)? But...both can't be "dominant".
125659. Berényi Péter at 03:22 AM on 30 December 2009
        Understanding Trenberth's travesty
        John Cook at 2009-12-12 23:44 PM wrote: "Trenberth states unequivocally that our planet is continually heating due to increasing carbon dioxide. This energy imbalance was very small 40 years ago but has steadily increased to around 0.9 W/m2 over the 2000 to 2005 period, as observed by satellites" No, he states nothing like that, unequivocally or otherwise. What Trenberth actually says is this: "There is a TOA imbalance of 6.4 W/m^2 from CERES data and this is outside of the realm of current estimates of global imbalances (Willis et al. 2004; Hansen et al. 2005; Huang 2006) that are expected from observed increases in carbon dioxide and other greenhouse gases in the atmosphere. 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" He simply sets the satellite-measured radiative energy balance of 6.4 W/m^2 at the top of the atmosphere to the entirely different value of 0.85 ± 0.15 W/m^2 based on climate models. It is equivalent to the proposition that satellite measurements are useless in this respect, so one has no choice but to verify climate model predictions using data derived from the model itself. In this case however, one can NOT say that the value of 0.9 W/m^2 is "observed by satellites". Or can, provided true and false statements have equal right to be uttered. EARTH’S GLOBAL ENERGY BUDGET by Kevin E. Trenberth, John T. Fasullo, and Jeffrey Kiehl http://ams.allenpress.com/archive/1520-0477/90/3/pdf/i1520-0477-90-3-311.pdf
        Response: I'm quoting Trenberth from the opening paragraph of  An imperative for climate change planning: tracking Earth's global energy (Trenberth 2009):

        Given that there is continual heating of the planet, referred to as radiative forcing, by accelerating increases of carbon dioxide (Figure 1) and other greenhouses due to human activities, why is the temperature not continuing to go up? The stock answer is that natural variability plays a key role [1] and there was a major La Nin˜ a event early in 2008 that led to the month of January having the lowest anomaly in global temperature since 2000. While this is true, it is an incomplete explanation.

        And a few paragraphs further along:

        Given that global warming is unequivocally happening [2] and there has so far been a failure to outline, let alone implement, global plans to mitigate the warming, then adapting to the climate change is an imperative.

        The broader point I was trying to make is that Trenberth's out-of-context quote was being used to portray him as privately not believing global warming is happening. This is decidedly not the case as is clearly communicated in the peer review literature.
125660. liaonet at 02:55 AM on 30 December 2009
        The albedo effect
        There is a growing body of evidence that in equatorial latitudes trees induce symbiotic bacteria and certain chemicals into their transpiration streams which increase reflective cloud cover over tropical forests during the day which is the best time to promote cooling. Please see www.weforest.com and read the white papers and watch the videos on our pages there.
125661. chris at 01:25 AM on 30 December 2009
        A visual deconstruction of a skeptic argument
        re response to post #1: It's worth pointing out that a recent analysis [*] supports the conclusion that the airborne fraction of anthropogenic CO2 is increasing, and with a larger trend than Knorr 2009 indicates, 'though as with Knorr 2009, the uncertainty is quite large. C. Le Quéré et al. (2009) Trends in the sources and sinks of carbon dioxide Nature Geosci. 2, 831-836. http://www.nature.com/ngeo/journal/v2/n12/abs/ngeo689.html
125662. neilperth at 20:26 PM on 29 December 2009
        1998 is not the hottest year on record
        Steve L @ 23 I have had a look at NASA's data and the current hot spot in Antarctica started around 1982, about the same time as the hot spot in Angola. That is based on 27 years of data and therefore I would argue reflects climate and not simpy weather. Also, with regard to which year has been hottest, taking into consideration the accuracy of the temp measurements ( +/- about 0.1 degree C according to NASA ) the years 1998, 2002,2003, 2005, 2006 and 2007, can be regarded as being of similar temperature.
125663. RSVP at 19:50 PM on 29 December 2009
        A visual deconstruction of a skeptic argument
        John, this article looks impervious to skeptic remarks, however, according to the numbers, ocean, land and vegetation absorb more CO2 than they put out. How then can any CO2 have remained if this process has been going on for millions of years?
        Response: Kudos for noticing! Ocean, land & vegetation are absorbing more than they emit because nature is partially absorbing the CO2 we're emitting. In other words, nature is trying to undo the impact we're having on the climate (I don't mean that in a mystical Gaia fashion - it's just a consequence of the nature of carbon sinks). Currently, nature absorbs about 45% of human CO2 emissions. The fraction that remains in the atmosphere, around 55%, is referred to as the "airborne fraction".
        
        One of the big questions concerning the carbon cycle is whether there's any trend in the "airborne fraction". Eg - is nature losing the ability to absorb our CO2 emissions? There have been some studies indicating that the oceans are getting saturated (Quéré 2007, Schuster 2007, Park 2008). On the other hand, an analysis of the airborne fraction has found a slight increasing trend in airborne fraction of 0.7 ± 1.4% per decade but the result is statistically insignificant (Knorr 2009). In other words, the status of the airborne fraction is pending.
125664. Ari Jokimäki at 19:28 PM on 29 December 2009
        Skeptical Science housekeeping: Translations and Comments Feed
        "Many thanks to Ari and Kaj for all their hard work (I'll try to keep my verbosity down in future posts to make things easier for you)." It's our pleasure. Thank you for making such an amazing resource. We are just glad that we can help in offering it also to (Finnish) people who don't understand English. Oh, and on the verbosity thing, don't hold back, keep giving us challenges. ;)
125665. Steve L at 17:36 PM on 29 December 2009
        1998 is not the hottest year on record
        #22. I think you might instead ask John Cook, or re-read the post. In the post, John writes that he would rather people focus on energy imbalance, but he thought it was also worthwhile to show that one specific year (1998) likely wasn't the warmest. It is only estimated to be the warmest in one case because of the limited spatial distribution of sampling in that case. You can compare the NASA GISS map in Fig 2 to the top panel of Fig 1 and see that the probable hottest year was 2005 owing to all that warmth in the polar regions where HadCRUT doesn't sample. That's what the maps are about. Re-read the post and tell me if you agree.
125666. neilperth at 14:34 PM on 29 December 2009
        1998 is not the hottest year on record
        Steve L @19 "For rates of global warming (large spatial scale), somewhere over 15 years is recommended in this post"... So I can disregard NASA's temperature map above as it reflects weather and not climate ? In that case, why was the map posted here?
125667. RSVP at 10:02 AM on 29 December 2009
        1998 is not the hottest year on record
        To Steve L To answer your question about what I meant. I suppose a very different picture is conceivable. One where the entire planet's temperature is raised slightly, everything one color for the most part, and possibly some holes where the trend is lagging. This being a situation where the temperature is increasing globally and in general unison.
125668. Steve L at 05:39 AM on 29 December 2009
        1998 is not the hottest year on record
        To follow up on my #18, RSVP, I know I have linked to RC to look up waste heat stuff before, and I think it is done better there, but see this too: http://mustelid.blogspot.com/2005/04/global-warming-is-not-from-waste-heat.html . And we know that anthropogenic aerosols are cooling the planet considerably: http://skepticalscience.com/CO2-is-not-the-only-driver-of-climate.html ' If ever asked how much CO2 contributes to global warming, you could say "all of it... and some!" ' Large industrial cities are responsible for a good proportion of the aerosols, so let me be the first one you've heard say, "cities cool the planet, with the exception of greenhouse gas production." Sorry for the off-topic, John. I don't know how to make this more relevant to your post.
125669. Steve L at 05:15 AM on 29 December 2009
        1998 is not the hottest year on record
        Neilperth @15 -- the difference between Figs 1 and 2 is that the latter compares individual years, whereas the former compares decadal averages. Weather effects become more important than climate effects as the temporal and spatial scales are reduced. For rates of global warming (large spatial scale), somewhere over 15 years is recommended in this post: http://tamino.wordpress.com/2009/12/15/how-long/
125670. Steve L at 05:07 AM on 29 December 2009
        1998 is not the hottest year on record
        RSVP@17: No, you haven't explained. You said two things in #9, both of which are at odds with Fig 2. You said GHG effects are downwind of waste heat sources (not "may be" as in #17), and I asked for explanation because Fig 2 seems to contradict you. You also said the data indicate the opposite of localized cool spots, but I see blue only in localized spots on Fig 2. You didn't explain that either. The Arctic is supposed to warm quickly, the Antarctic is not. I don't know why you persist in insinuating that regional patterns of warming are unexpected from AGW theory. I thought you were cured of that (http://www.skepticalscience.com/Was-there-a-Medieval-Warm-Period.html see your much appreciated response at comment #42). Your response in #17 above is a bit of a jumble, and it's probably not worth delving into here (even if I had the expertise) because (1) this post is about how hot 1998 was, and (2) the figures we're discussing (esp Fig 2) have observational periods that are too brief. Finally, I didn't notice in the video someone saying that cities cooled the Earth. Did you? The only time I ever heard that was at a talk given by Hadi Dowlatabadi who gave the example of Pittsburgh -- the aerosols from post-war industry there apparently reduced the temperature of the city by quite a bit. I can't find the ref. But if you want a big picture view, go no further than our host's other pages. For example: http://www.skepticalscience.com/urban-heat-island-effect.htm
125671. neilperth at 03:15 AM on 29 December 2009
        Predicting future sea level rise
        Bern @46 Potential crop failures,famines, severe water shortages, wars, diseases etc are things which mankind has had to battle in the past and no doubt these phenomena will occur in the future with or without alleged man-made global warming. With regard to sea level rise, we have yet to see the "catastrophic" rise in sea level forecast by climate researchers. And if sea level does rise, I don't think it will rise so fast that nothing can be done to help mitigate the effects. By the same token, when the next ice-age comes this will also cause mankind some hardship. Even Hansen discusses the possibility of a mini ice-age in the coming decades. One of the big challenges that mankind faces is the population explosion - about an extra 160 million extra people every year as I understand. All of these will require energy for warming, cooling, cooking etc etc.
125672. RSVP at 03:11 AM on 29 December 2009
        1998 is not the hottest year on record
        #14, Approximately Angola, the Antarctic Peninsula, north of the Faulkland Islands, Siberia, Uzbekistan, Siberia, and the Western Arctic seem to be the reddest. Please explain. ////////////// I already explained above, and I did watch the video. The link is very apropo and appreciated, however the style is defensive and biased giving it a political campaign type feel. I would like to answer your question in part by asking another question. Are red and purple splotches random, or might there not be a particular reason why some parts of the world are warming in general more than others? And if we had maps comparing temperatures over ten year intervals going back in time 1000 years, would one expect temperature cycles to have a homogeneous distribution, or resemble the kind of thing we are seeing here? I would assume that even in a totally non anthropogenic scenario, you would have uneven warming, for whatever the causes. However in the case here, these patterns are due in part by nature and in part by man. Drivers such as waste heat may be local or downwind as I was saying. The cumulative effect of an urban continent such as Europe, or metropolis such as Los Angeles, Mexico City cannot be cooling the Earth. I dont think anyone is denying this. (Maybe the video is and exception) I would also ask if polar zones arent more prone intrincially to have their average temperatures change given that they are dry, and represent the tail "edge" of the planet's net thermal energy reservoir.
125673. neilperth at 20:00 PM on 28 December 2009
        1998 is not the hottest year on record
        The red hot-spot anomaly in Antarctica, just below the tip of South America sticks out like a sore thumb and is partly surrounded by areas which are cooling. How is this explained ? What is special about the area where the hot-spot occurs ?
        Response: This is possibly due to the cyclonic conditions around Antarctica which lead to dramatic warming in West Antarctica and cooling in the East Antarctic interior. I touch on it briefly when looking at Antarctic sea ice.
125674. neilperth at 19:56 PM on 28 December 2009
        1998 is not the hottest year on record
        In figure 2 you will see a hot spot in Angola where temp change from 2001 to 2005 had increased by about 1.8 degrees. And in general most of south Angola has warmed by about 1.2 degrees But on the ECMWF map, (1998-2008)the reverse is shown. The location of the hot spot in figure 1 has actually cooled by 0.3 degrees and in general the south of Angola has cooled. Or to put it another way, figure 2 shows appreciable warming in South Central Africa while the ECMWF map shows cooling to no change in the same area. How is this explained ?
125675. fudge123 at 19:46 PM on 28 December 2009
        It's cooling
        ''The atmosphere is warming'' My understanding is that is not warming enough to be able to confirm that an increased greenhouse effect is causing global warming. Also it's not warming enough in the right area which is supposed to be in the Troposphere at around 10km. Has this suddenly changed? Also regarding ''Oceans are accumulating energy'' Some 3,000 scientific robots that are plying the ocean have sent home a puzzling message. These diving instruments suggest that the oceans have not warmed up at all over the past four or five years. That could mean global warming has taken a breather. Or it could mean scientists aren't quite understanding what their robots are telling them But Josh Willis at NASA's Jet Propulsion Laboratory says the oceans are what really matter when it comes to global warming. In fact, 80 percent to 90 percent of global warming involves heating up ocean waters. They hold much more heat than the atmosphere can. So Willis has been studying the ocean with a fleet of robotic instruments called the Argo system. The buoys can dive 3,000 feet down and measure ocean temperature. Since the system was fully deployed in 2003, it has recorded no warming of the global oceans
        Response: Josh Willis is right. Over 90% of global warming goes into the oceans. Some studies of upper ocean heat (using the "3000 robots" that comprise the Argo network) have shown cooling over the last few years during a time when the Pacific has transitioned from El Nino to La Nina conditions. However, when the Argo data is examined to greater depths, down to 2000 metres, it's seen that the ocean is still accumulating heat (von Schuckmann 2009):
        
        
125676. Leo G at 06:45 AM on 28 December 2009
        Could CFCs be causing global warming?
        So I take it that this theory is that as the sun settles down, and more CR's gain entry into the stratosphere, they react with the CFC's and drive more O3 loss, right? With less O3 in the strat, more of the sun's rays can now reach the earth, but on the other hand, more of the earth's emmisions can now travel out to space "easier". So is he saying that with less ozone more energy escaped the earth compared to the extra amount coming from the sun?
125677. Leo G at 06:34 AM on 28 December 2009
        Could CFCs be causing global warming?
        Here's a paper from RC from last year that seems to put this into a bit better perspective; http://www.realclimate.org/index.php/archives/2008/12/ozone-holes-and-cosmic-rays/
125678. Steve L at 04:37 AM on 28 December 2009
        1998 is not the hottest year on record
        #9, Looking at Fig 2 above, I see what you say we should expect: "(last vestiges of cooler zones) appearing as remanant localized cold spots" -- there are really just a few speckles of blue. Then, when I look at the hottest spots in Fig 2, I don't see them being downwind of "coincidentally downwind of locales where waste heat is being generated". Approximately Angola, the Antarctic Peninsula, north of the Faulkland Islands, Siberia, Uzbekistan, Siberia, and the Western Arctic seem to be the reddest. Please explain. http://www.youtube.com/watch?v=B7OdCOsMgCw (This Peter Sinclair video may not be appropriate [strays from scientific discourse in places] but it does some nice things with maps of heat and people.)
125679. Steve L at 04:18 AM on 28 December 2009
        Could CFCs be causing global warming?
        Well, the abstract is interesting and suggests that a broad range of material will be presented. It surprised me that the paper has just one author, but then I read that Lu is cross appointed in three departments.... Anyway, I would have liked to read the paper, but it ain't free. One potential triviality that caught my interest is the secondary axis in Figure 1: Normalized EESC. Is this standard normal deviates? I wouldn't think so, but why not present the data in ppm or something? At a broader level of response, I'm thinking of ozone holes being polar phenomena and wondering about Lu's choice of a temperature record that mostly ignores these regions. I'd like to hear about the distribution of CFCs in relation to ozone holes and whether this is relevant to interpretation of Lu's results. And now a borderline off-topic comment: I think we have a lot to learn from the CFC-ozone story (or at least I do), including topics of denial (support for inaction), public education, innovation and solution (Montreal Protocol). This paper seems to stray from several standard assertions of AGW-deniers (e.g., http://skepticalscience.com/Are-humans-too-insignificant-to-affect-global-climate.htm , http://www.sepp.org/key%20issues/ozone/ozdeplth.html ). Lu's paper is at odds with much of the science on climate change (as the post shows nicely), but I think its deviation from common talking points could be more fatal to its eventual popularity (and ranking among the hottest skeptical arguments). I'm assuming here from the abstract that Lu finds support for anthropogenic ozone depletion. Is that assumption correct?
125680. teo at 03:51 AM on 28 December 2009
        Understanding Trenberth's travesty
        My question is: why Trenberth did not put the same question about the accuracy of surface data when the temperasture increase appeared to be unstoppable? It does not appear to me 'a clear, open, manner' to manage the issue.
125681. batsvensson at 03:05 AM on 28 December 2009
        1998 is not the hottest year on record
        @RSVP in #9, On can think about it in this way: Since water vapor dominating the green house effect, and since water vapor varies in concentration in the atmosphere, and if CO2 is uniformly distributed, and if CO2 has a significant effect, then it follows the warming will be greater at those places where water vapor has less concentration. Therefore, since water vapor concentration is lower at the polar region the prediction is that warming due to CO2 should be greater at the polar regions.
125682. stephan linn at 02:33 AM on 28 December 2009
        Could CFCs be causing global warming?
        "When one considers the energy building in the entire climate system (especially the oceans where most heat resides), we see that the planet is still accumulating heat through to 2009 (Murphy 2009, von Schuckmann 2009)." These two papers don't outweigh the Argo data which indicate flat or decreasing upper ocean temperatures. Since this is consistent with land and atmospheric measurements, we should conclude the earth is not accumulating heat unless it is in the deep oceans. I am not aware of a plausible mechanism for this.
        Response: von Schuckmann 2009 does use Argo data. Other recent papers on ocean heat trends focused on upper ocean heat which shows more variability than measurements down to 2000 metres which is what von Schuckmann does, showing a less noisy signal:
        
        
        
125683. Ari Jokimäki at 19:28 PM on 27 December 2009
        Could CFCs be causing global warming?
        Hofmann et al. (2006) might be of interest here. They show (from direct observations) that radiative forcing from both CFC-11 and CFC-12 has decreased since 1980's.
125684. neilperth at 15:18 PM on 27 December 2009
        Predicting future sea level rise
        Phillipe...... I find your reply rather baffling. Of course corruption happens in every country of the world. Where did I state otherwise ? Although in my case it is only in African countries that I have had to pay bribes to leave the country and have my money mysteriously disappear from my bank account. Situations which I have yet to experience in Europe. Also, where did I state that we do nothing with regards to global warming ? If burning coal to produce power causes global warming, then one obvious solution is to go nuclear. But over the years environmental groups have fought against using nuclear power to generate electricity and the result was that in Australia, for example, we have had to rely mainly on coal fed power stations. And now the same environmental groups are complaining that this causes global warming. Yes, my "characterization of the compensation intended" is accurate - developing nations around the world are demanding hundreds of billions of dollars per annum. Introducing a world-wide ETS will inflate the cost of just about everything in the Western world. And when you consider that much of the goods and services consumed in developing countries are imported, this will mean that the increased cost of these goods and services will be passed on to these countries. So while the developing countries will get billions of dollars in compensation, they will also be paying billions of extra dollars in the form of higher prices for goods and services.
125685. Terry Oldberg at 12:34 PM on 27 December 2009
        Models are unreliable
        The claim is made that the climate models "...have made predictions that have been subsequently confirmed by observations. This claim is refuted by the noted climatologist Kevin Trenberth; he states at http://blogs.nature.com/climatefeedback/recent_contributors/kevin_trenberth/ that that the models referenced by the United Nations Intergovernmental Panel on Climate Change do not make predictions. It follows that: a) the UN-IPCC models are not falsifiable and b) the IPCC models are not scientific, by the definition of "scientific." Rather than make predictions, the IPCC models make what the IPCC calls "projections." A "projection" is a mathematical function which maps the time to the global average temperature. A "prediction" is a logical proposition which states the outcome of a statistical event. A "projection" supports comparison of the computed to the measured temperature and computation of the error. However, it does not support falsification of the model for the apparatus is not present by which the proje3ction may be proved wrong. A "prediction" provides this apparatus.
125686. Leo G at 15:50 PM on 26 December 2009
        1998 is not the hottest year on record
        From the report: (quote)"The implication of these studies is that, should greenhouse gas emissions continue on their current course of increase, we are virtually certain to see Earth's climate warm by several degrees Celsius in the next century, unless some strong negative feedback mechanism emerges elsewhere in Earth's climate system," Dessler said(end quote) Lovely phrasing here. Dressler is a true scientist, IMHO.
125687. Leo G at 15:34 PM on 26 December 2009
        1998 is not the hottest year on record
        RSVP CO2 is not well mixed in the troposphere according to this NASA release: http://www.jpl.nasa.gov/news/news.cfm?release=2009-196 Some interesting things happening right now in the science, as more results start arriving from better equipment.
125688. Philippe Chantreau at 08:36 AM on 26 December 2009
        1998 is not the hottest year on record
        Merry Christmas, happy new year and thanks for all your hard work John.
125689. RSVP at 06:39 AM on 26 December 2009
        1998 is not the hottest year on record
        The fact that there are localized hot spots leading a global warming trend seems to suggest these as sources of heat which radiate outward. Greenhouse gases fill the entire atmosphere equally. Why do their effects precede locally, and coincidentally downwind of locales where waste heat is being generated? Conversely, if the heat source was homogeneous, you would expect to see exception (last vestiges of cooler zones) appearing as remanant localized cold spots, yet the data indicates just the opposite.
125690. RSVP at 06:26 AM on 26 December 2009
        1998 is not the hottest year on record
        Comparing the lower figures 1 with figure 3, the dynamic ranges in temperature are about the same, yet the time span for figure 3 includes only half as many years within the same period. This constitutes a fairly large discrepancy unless this implies a curve that peaks or flattens out somewhere in the middle.
125691. Leo G at 18:43 PM on 25 December 2009
        1998 is not the hottest year on record
        Merry Christmas to all, and praying for a peaceful 2010! Thanx John for your time and patience. May Santa be kind to you and yours!
125692. Philippe Chantreau at 06:20 AM on 25 December 2009
        Predicting future sea level rise
        You have nothing to teach me on the subject, unfortunately. I grew up in Africa and worked there too. My parents lived and worked there for 17 years. A closer look at European countries and the US taught me that no category of country has a monopole on corruption, which is simply a feature of Human nature. In Africa, it is more obvious because they don't care about appearances as much and the underlying poverty is, by our standards, extreme. I'm not sure your characterization of the compensation intended is really accurate, but in any case, what else do you propose be done? Nothing? Integrate the real price of carbon in the world's economy without softening the impact in some way to the most vulnerable, who will also likely be the most affected by climate change? These countries have benefited from assistance before, even if the benefits were reduced by corruption. Should nothing have been done then? That would have been a more rational thing to do? In any case, this is OT. I apologize to John for starting the discussion and won't pursue it.
125693. doskonaleszare at 01:18 AM on 25 December 2009
        1998 is not the hottest year on record
        The paper is Simmons, A. J., K.M. Willett, P.D. Jones, P. W. Thorne, and D. Dee (2009), Low-frequency variations in surface atmospheric humidity, temperature and precipitation: Inferences from reanalyses and monthly gridded observational data sets, J. Geophys. Res., doi:10.1029/2009JD012442, in press.
125694. PeterPan at 00:18 AM on 25 December 2009
        Hockey sticks, 'unprecedented warming' and past climate change
        The same as Chris said: WWT has added the global temperature record (0,6ºC), but Greenland has experienced much more warming than the global average. These two reconstructions clearly show a warming of more than 1 ºC, therefore, temperatures in Greenland are probably warmer now than they were in the MWP (in spite of the fact that the MWP was mainly focused on the North Atlantinc around Greenland): FIG. 11. Greenland ice sheet land station record annual temperature anomalies with respect to the 1951–80 base period. Multiples of standard deviations for the 1951–80 period are included. Major volcanic eruptions are indicated Source: Greenland Ice Sheet Surface Air Temperature Variability: 1840–2007 (full pdf, PPT) Jason E. Box, Lei Yang, David H. Bromwich y Le-Sheng Bai Journal of Climate, Volume 22, Issue 14 (July 2009) Fig. 2. (a) Mean annual temperature (TMA) difference averaged over ice-sheet area, assembled from two datasets: ECMWF re-analyses (blue) and BOX (red) Source: Surface mass-balance changes of the Greenland ice sheet since 1866 (full pdf) Wake et al 2009 Annals of glaciology., 50 (50). pp. 178-184 It is curious that much of the warming there took place at the begining of the century (though anomalies are now greater). It seems that there is great variability there, probably related to the Arctic amplification.
125695. JD Will at 23:40 PM on 24 December 2009
        Hockey sticks, 'unprecedented warming' and past climate change
        

        "Now one could nitpick the analysis by pointing out that it focuses on one location in Central Greenland. Temperature at a single location inevitably show greater variation than the global average. "

        Aren't the long time scale proxies necessarily spotty? I am trying to learn as much as possible, and let me state my position before asking questions. I believe CO2 is a good prima facie argument for observed warming. I am not strong enough in science to judge between many seemingly convincing arguments (more on that later), but I do believe we need to be seriously thinking about it. I think we need to look at all of mitigation, adaptation, and possible counter climate engineering. We also need to get statisticians and economists involved in these debates as well - cross discipline review and hard analysis will help, not hurt. The scene at Copenhagen was very disappointing for anyone who cares about environment - it looked from here like a mixture of magical thinking and silly UN politics. I also am deeply suspicious of cap and trade - it looks more like a way for scam artists to get rich than a way to really make a change. That said, I am trying to learn as much as possible about the science. It is fascinating to me. I have just watched (twice) a lecture by Dr Richard B Alley that opened my eyes about CO2 a bit. The compliment to him is that a laymen can get a lot from his talk. http://www.agu.org/meetings/fm09/lectures/lecture_videos/A23A.shtml He discusses several CO2 proxies but mentions that the Antarctic ice is the gold standard for reconstruction. He mentions some glitchiness in Greenland ice. Also at points he alludes to certain temperature records being uncertain due to locality. I have two questions: 1. How well spread out are the proxy records for temperature and CO2? Is there a chart that shows what proxies are available for each time scale? 2. How well do proxies agree, and what statistical methods are used to resolve them to the one line graphs I see in so many presentations? That is, what is the error margin when extrapolating global averages from them? For example this graph apparently shows various NH proxies. They seem to vary quite a bit to me. http://physicist.org/history/climate/images/ipcc_6_10_sm.jpg What I am driving at is that these are northern hemisphere, but I don't see a similar SH. How do we know what the global temp was and with what accuracy? We seem to are talking about a degree or two or less over a thousand year period.
125696. Donald Lewis at 19:15 PM on 24 December 2009
        1998 is not the hottest year on record
        Thanks for this alert, and thanks to the Met Office for posting this release. I have been suggesting to 'climate science' denier friends that the lack of polar temp estimates were accounting for some of the differences between HadCRUT3 and GISS 'global' estimates. Glad there is now a scientific study, apparently, investigating this difference between the reports of global temps of the Met Office and, say, Goddard. As this is an instance of 'climate science' it will probably have little impact on my 'science is a conspiracy' oriented friends, but is good to have available for voting bystanders who listen with both ears. Thanks for the update!
125697. neilperth at 16:19 PM on 24 December 2009
        1998 is not the hottest year on record
        Tom......... I was thinking more of the difference in temps between the areas north and south of the Persian Gulf. I am not talking about local temp differences on the scale of cities - the hot spot north of the Persian Gulf for example is about the size of India. Have the original temp data been kriged to get the "blocked" temp data ? If so this produces a smoothing effect which means that the original ( raw ) temp differences were even greater than shown.
125698. Tom Dayton at 15:21 PM on 24 December 2009
        CO2 is not a pollutant
        Some plants grow worse at higher temperature, offsetting gains from CO2 spurring growth. Examples are in tables in the USDA report I linked to in my earlier comment.
125699. Tom Dayton at 15:20 PM on 24 December 2009
        It's not bad
        Plants can't grow any better than their limiting factor, which might be not CO2, but nitrogen, water, light,.... Some plants grow worse at higher temperature, offsetting gains from CO2 spurring growth. Even if they do grow "better," the betterment often is not to the advantage of farmers; for example, the extra mass can go into non-consumable woody stalk, which makes the crop more expensive to process than any extra grain/fruit value. And weeds such as poison ivy and kudzu respond much "better" to increased CO2 than do many crops, but "better" is not better for people, and not better for plants that those weeds compete with. For details see the U.S. Department of Agriculture's report on climate change.
125700. Tom Dayton at 15:17 PM on 24 December 2009
        CO2 is not a pollutant
        Plants can't grow any better than their limiting factor, which might be not CO2, but nitrogen, water, light,.... Even if they do grow "better," the betterment often is not to the advantage of farmers; for example, the extra mass can go into non-consumable woody stalk, which makes the crop more expensive to process than any extra grain/fruit value. And weeds such as poison ivy and kudzu respond much "better" to increased CO2 than do many crops, but "better" is not better for people, and not better for plants that those weeds compete with. For details see the U.S. Department of Agriculture's report on climate change.

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