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Comments 130951 to 131000:

130951. Quietman at 03:58 AM on 10 October 2008
        Is Antarctic ice melting or growing?
        chris "assumptions that unfortunately do not survive real world analysis/observation." My remark was from personal observation as stated. That is what I do in retirement, grow things. That is why I was questioning Mizimi in the solar thread about C3 versus C4 flora. I plant small patches of different types of fruit and vegetables on one acre (spaced so they do not interfere with each other), on half the remaining acres I manage the forest and on the other half I let it do it's thing. The half I am managing I spray foe Japanese Beetles on the wild berry bushes and tent worms in the trees as well as planting trees that were not found on the property to observe which grow best in this climate. What I have obsevered is that evergreens are not as hardy or grow as quickly as leafy trees and shrubs and that the wild fruit trees and bushes are doing as well as the domesticated ones that I planted, in fact extremely well while the white cedars I planted died after trying for two years. The red cedar is doing OK as are the different spruces, maples, oaks and apple trees but not the hickories. There were no rasberry bushes here when I bought this place in 2002 and now both halves are full of wild rasberry and blackberry bushes. I don't offer this as proof of anything, only to explain my statement since eastern PA has increased CO2 levels and is more humid than in the past but it really isn't any warmer in this area (in fact the local airport records indicate the opposite), but it seems to be warmer longer (shorter spring weather) but that is heresay and not verified.
130952. DB2 at 03:38 AM on 10 October 2008
        Is Antarctic ice melting or growing?
        Chris, that is a lot to respond to a one time. I will post some research articles as time allows. First, plant productivity has already increased. This article from 2003 indicates that global net primary production on the land increased 6% between 1982 and 1999. (NPP is the difference between the CO2 absorbed by plants during photosynthesis, and CO2 lost by plants during respiration.)` Changes in the world's oceans were not included. The authors write, "Our results indicate that global changes in climate have eased several critical climatic constraints to plant growth, such that net primary production increased 6% (3.4 petagrams of carbon over 18 years) globally." Climate-Driven Increases in Global Terrestrial Net Primary Production from 1982 to 1999 R.R. Nemani et al. Science (2003) Vol. 300 1560-1563 http://cybele.bu.edu/globalgarden/nemani01.pdf Climate predictions are also iffy on a regional basis, and I'll dig up an article or two on the limitations of regional models. For now, I'll remind ourselves of the great hue-and-cry over the Sahel two or three decades ago. Now it seems things aren't so bad. This article on the Sahel finds that it has experienced an increase in vegetative output that has been, as Olsson writes, "remarkable." A recent greening of the Sahel — trends, patterns and potential causes L. Olsson et al. Journal of Arid Environments 63(2005) 556–566 http://meteo.lcd.lu/globalwarming/Ollson/recent_greening_of_... Abstract: For the last four decades there has been sustained scientific interest in contemporary environmental change in the Sahel (the southern fringe of the Sahara). It suffered several devastating droughts and famines between the late 1960s and early 1990s. Speculation about the climatology of these droughts is unresolved, as is speculation about the effects of land clearance on rainfall and about land degradation in this zone. However, recent findings suggest a consistent trend of increasing vegetation greenness in much of the region. Increasing rainfall over the last few years is certainly one reason, but does not fully explain the change. Other factors, such as land use change and migration, may also contribute. This study investigates the nature of a secular vegetation trend across the Sahel and discusses several potential causative factors.
130953. Quietman at 15:04 PM on 9 October 2008
        Climate sensitivity is low
        Re: "Simple Question, Simple Answer… Not" Interesting comments from John Mashey: [[ John Mashey Says: 8 September 2008 at 2:31 PM “These people, typically senior engineers, get suspicious”. Please, can we get deeper than “senior engineers” - that really isn’t improving insight. If we want to do that, we need to probe a lot deeper than just “senior engineers”. Let me offer a speculation, although not yet a serious hypothesis: 1. SPECULATION Amongst technically-trained people, and ignoring any economic/ideological leanings: 1) Some are used to having a) Proofs OR b) Simple formulae OR c) Simulations that provide exact, correct answers, and must do so to be useful d) And sometimes, exposure to simulations/models that they think should give good answers, but don’t. 2) Whereas others: a) Are used to missing data, error bars, b) Complex combinations of formulae c) Models with varying resolutions, approximations, and that give probabilistic projections, often only via ensemble simulations. d) Models that are “wrong”, but very useful. My conjecture is that people in category 1) are much more likely to be disbelieving, whether in science, math, or engineering. 2. ANECDOTAL EXAMPLES: 1) In this thread, a well-educated scientist (Keith) was convinced that climate models couldn’t be useful, because he was used to models (protein-folding) where even a slight mismodel of the real world at one step caused final results to diverge wildly … just as a one-byte wrong change in source code can produce broken results. See #197 where I explained this to him, and #233 where light dawned, and if you’re a glutton for detail: #66, #75,l #89, #1230, #132, #145, $151, #166 for a sample. 2) See Discussion here, especially between John O’Connor & I. See #64 and #78. John is an EE who does software configuration management. When someone runs a rebuild of a large software system, everything must be *perfect*. There’s no such thing as “close”. Also in that thread, Keith returned with some more comments (#137) and me with (#146), i.e., that protein-folding was about as far away from climate modeling as you could get. 3) Walter Manny is a Yale EE who teaches calculus in high school. He’s posted here occasionally (Ray may recall him :-), and participated in a long discussion at Deltoid, and has strong (contrarian) views. In many areas of high school/college math, there are proofs, methods known for centuries, and answers that are clearly right or wrong. 4) “moonsoonevans” at Deltoid, in #21 & #32 describes some reasons for his skepticism, #35 is where light dawns on me. He’s in financial services, had experienced many cases where computer simulations done by smart people didn’t yield the claimed benefits. In #35 I tried to explain the difference. All this says that if one is talking with an open-minded technical person, one must understand where *they* are coming from, and be able to give appropriate examples and comparisons, because many people’s day-to-day experience with models and simulations might lead them to think climate scientists are nuts. 3. A FEW SPECIFIC DISCIPLINES & CONJECTURES 1) Electrical engineers (a *huge* group, of which only tiny fraction are here) Many EEs these days do logic design, which requires (essentially) perfection, not just in the design, but (especially) in simulation. Design + input =>(logic simulator) => results At any step, the design may or may not be bug-free, but the simulator *must* predict the results that the real design would do given the input, exactly, bit for bit. Many test-cases have builtin self-checks, but the bottom line is that every test-case yields PASS or FAIL, and the simulator must be right. Many people buy simulators (from folks like Cadence or Synopsys), and run thousands of computers day and night simulating millions of test-case inputs. But, with a million test-cases, they’re not looking for an ensemble that provides a distribution, they’re looking for the set of test-cases to cover all the important cases, and for EVERY one to pass, having been simulated correctly. This has some resemblance to the protein-folding problem mentioned above. Now, at lower levels of timing and circuit design, it isn’t just ones and zeroes (there’s lots of analog waveforms, probabilistic timing issues, where one must guarantee enough margin, etc). When I’d tease my circuit designer friends “Give me honest ones and zeroes”, they’d bring in really ugly, glitchy HSPICE waveforms and say “so much for your ones and zeroes”. (This is more like the molecular “docking” problems that Keith’s colleagues mentioned.) At these levels, people try to set up rules (”design rules”) so that logic designers can just act at the ones-and-zeroes level. If one looks at EEs who worry about semiconductor manufacturing, they think hard about yields, failure attribution, and live with time-series. (Standard answer to “We got better yield this month, how do you think it looks?” was “Two points don’t make a trend.” 2) Software engineers Programs often have bugs, but even a bug-free program can fall apart if you change the wrong one byte of code, i.e., fragile. (I don’t recall the source, but the old saw goes something like: if skyscrapers were like software, the first woodpecker would knock them over.) Configuration management / software rebuilds are fairly automated these days, and they must be correct. One cannot include the wrong version of code, or compile with incompatible options. Performance engineering and benchmarking tend to be more probabilistic-oriented, and although a lot of people want to believe in one number (once the mythical “MIPS” rating), we’ve (mostly) fixed that over the last 20 years. Good performance engineers have always given relative performance ranges and said YMMV (Your Mileage May Vary). 3) Mechanical engineers This, I expect, varies. In some cases, closed-form equations work pretty well. In other cases, one is using big structural dynamics and computational fluid dynamics codes to obtain “good-enough” approximations to reality before actually building something. For example, automobiles are extensively modeled via “crash codes”. 4) Petroleum engineers It’s been a while, but certainly, people who do seismic analysis and reservoir modeling *start* with data from the real world, analyze it to make decisions, so ought to be a little more accustomed to probabilistic analyses. 5) Financial engineers (Google: financial engineering) Not having physics to constrain simulations yields some wild results, although at least, some people are very comfortable with risk, uncertainty, and ensemble projections. I especially like Sam Savage’s Flaw of Averages”. On the other hand, when Nobel Economists lose $B (LTCM), I’m not surprised there is skepticism about climate models. 4. CONCLUSIONS That’s a speculative start. I do *not* think lumping a large group together as “senior engineers” helps progress, because I have at least anecdotal evidence that the sources of skepticism tend to be attached to the kinds of models and (maybe) simulations that someone does day-by-day. The problem is that many people tend to generalize from their discipline to others, and especially if they have trouble getting useful models, they tend to be suspicious of others’. At one extreme, people have long-established mathematical proofs, and answers that are clearly right or wrong. At the other extreme, people have to make decisions based on the best approximations they can get, and if their discipline has good-enough approximations, they tend to think one way, and if the approximations aren’t so good, they may think another about equations and climate models. ]] Since both 2 and 3 apply personally I can relate.
130954. Quietman at 14:54 PM on 9 October 2008
        Climate sensitivity is low
        Patrick William Collins, Robert Colman, James Haywood, Martin R. Manning and Philip Mote" "Drivers of Climate Change Atmospheric concentrations of many gases—primarily carbon dioxide, methane, nitrous oxide and halocarbons (gases once used widely as refrigerants and spray propellants)—have increased because of human activities." True IF based on high sensitivity.
130955. Quietman at 14:37 PM on 9 October 2008
        It's the sun
        chris As you are aware, I don't think the warming is from the sun alone, anymore than from GHGs. I made my arguments in the volcanos thread so I won't put an argument here.
130956. Adamski at 13:19 PM on 9 October 2008
        Climate's changed before
        Has any research been done on just how much water vapour can be held in the atmosphere and the warmer temperatures before it reaches saturation point? And also explain to me why Douglas Hoyt's info is so dodgy. He's fairly knowledgeable in the field so why is his contribution so wrong? How do we know what's right or wrong? You can justify comments with 'scientific proof' but how do we know that it is correct? Are you prepared to take anyones word for it? Is there some corruption not only from the climate change skeptics but also from the IPCC and other anthropogenic climate change supporters? It's all very interesting but doesn't everyone within this current issue have an agenda?
130957. chris at 08:06 AM on 9 October 2008
        Is Antarctic ice melting or growing?
        Re #5 DB2/#6 Quietman Those assumptions (warmer = more humid....or warm + humid + CO2 = more plant growth) unfortunately do not survive real world analysis/observation. As the earth warms, the atmosphere supports raised water vapour concentrations. What effect does this have on precipitation patterns? It would be wonderful to think that this will have beneficial effects on agricultural production (for example). Sadly, that's already being shown not to be the case. While global warming is resulting in enhanced atmospheric water vapour concentrations as predicted by theory/models, this doesn't translate into useful enhancement of rainfall. In fact the effect on rainfall patterns is pretty much exactly what we don't want. This has been analyzed recently in studies of warming-induced variation of precipitation. In esssence, just as models predict, those regions of the earth that have limited water supply, have a REDUCTION of precipitation (the equatorial regions between around 0 - 30 o N), whereas those regions that have generally useful or abundant precipitation, will have to cope with enhanced precipitation. That's already happening, even 'though global warming is rather in its incipient stages so far: Zhang XB (2007) "Detection of human influence on twentieth-century precipitation trends" Nature 448, 461-465. Abstract: "Human influence on climate has been detected in surface air temperature(1-5), sea level pressure(6), free atmospheric temperature(7), tropopause height(8) and ocean heat content(9). Human-induced changes have not, however, previously been detected in precipitation at the global scale(10-12), partly because changes in precipitation in different regions cancel each other out and thereby reduce the strength of the global average signal(13-19). Models suggest that anthropogenic forcing should have caused a small increase in global mean precipitation and a latitudinal redistribution of precipitation, increasing precipitation at high latitudes, decreasing precipitation at sub-tropical latitudes(15,18,19), and possibly changing the distribution of precipitation within the tropics by shifting the position of the Intertropical Convergence Zone(20). Here we compare observed changes in land precipitation during the twentieth century averaged over latitudinal bands with changes simulated by fourteen climate models. We show that anthropogenic forcing has had a detectable influence on observed changes in average precipitation within latitudinal bands, and that these changes cannot be explained by internal climate variability or natural forcing. We estimate that anthropogenic forcing contributed significantly to observed increases in precipitation in the Northern Hemisphere mid-latitudes, drying in the Northern Hemisphere subtropics and tropics, and moistening in the Southern Hemisphere subtropics and deep tropics. The observed changes, which are larger than estimated from model simulations, may have already had significant effects on ecosystems, agriculture and human health in regions that are sensitive to changes in precipitation, such as the Sahel." Allan, R P & Soden, B J (2008) Atmospheric warming and the amplification of precipitation extremes" Science 321, 1481-1484. Abstract: "Climate models suggest that extreme precipitation events will become more common in an anthropogenically warmed climate. However, observational limitations have hindered a direct evaluation of model- projected changes in extreme precipitation. We used satellite observations and model simulations to examine the response of tropical precipitation events to naturally driven changes in surface temperature and atmospheric moisture content. These observations reveal a distinct link between rainfall extremes and temperature, with heavy rain events increasing during warm periods and decreasing during cold periods. Furthermore, the observed amplification of rainfall extremes is found to be larger than that predicted by models, implying that projections of future changes in rainfall extremes in response to anthropogenic global warming may be underestimated." And of course the notion that enhanced warming and raised CO2 levels is "good" for plant growth is also a fallacy when translated into the real world especially with respect to agricultural production. What happens in controlled greenhouse experiments under conditions of optimal nutrient supply and careful temperature/hydrological control, doesn't translate into the real world. Despite enhanced atmospheric CO2 and "raised" world wide humidity, it's predicted that Southern Africa will lose around 30% of its staple crop (maize) in the next 20 years...Southern Asia will have substantially reduced yields of rice, millet and maize and so on. These effects relate to the predicted and observed REDUCED precipitation/raised temperature in the low latitude equatorial belt in a warming world, already underway as described above: David B. Lobell et al. (2008) "Prioritizing Climate Change Adaptation Needs for Food Security in 2030" Science 319, 607-610. Abstract: "Investments aimed at improving agricultural adaptation to climate change inevitably favor some crops and regions over others. An analysis of climate risks for crops in 12 food-insecure regions was conducted to identify adaptation priorities, based on statistical crop models and climate projections for 2030 from 20 general circulation models. Results indicate South Asia and Southern Africa as two regions that, without sufficient adaptation measures, will likely suffer negative impacts on several crops that are important to large food-insecure human populations. We also find that uncertainties vary widely by crop, and therefore priorities will depend on the risk attitudes of investment institutions." Sadly, life and the real world isn't accommodating of simplistic hopeful predicted consequences. A warming world is not a world with enhanced prospects for either agricultural production, or a reduction in sea level rise due to enhanced snow deposition at the poles. The expectation is that sea levels are going to rise and agricultural production is going to decrease as the earth continues to warm. We'll have to work very hard, and at great expense to adapt. Those people least equipped to do so will (as usual) bear the brunt of the hardships....
130958. chris at 00:27 AM on 9 October 2008
        CO2 measurements are suspect
        Re #1 That really doesn't make much sense Mizimi. Since the atmosphere is a relatively well-mixed medium, one doesn't need a whole network of sites measuring CO2 to obtain a pretty accurate measure of global atmospheric CO2 concentrations. It's not like a temperature measurement which is a highly local parameter, even if this may be correlated with temperature measurements up to quite a large distance away. Again this is straightforward to demonstrate. For example if you click on John's link above to the NOAA site you will see that the Manua Loa CO2 measurements and the globally averaged sea surface measures match very closely (within around 1 ppm). Even comparing Northern hemisphere and S hemisphere averages, the numbers are pretty similar, especially when averaged over a year. What's fascinating about your post is that on another thread ("It's the sun"), you promote the awesomely inept analysis of paleo CO2 measures of a German school teacher (Mr Beck), who "finds" historical CO2 measures that jump up and down wildly (100 ppm in a few years!). Now if one actually examines the original papers from which Beck's weird analysis descends, you find a bunch of wildly unrepresentative CO2 measurements made in cities. We know these give false measures of the globally averaged atmospheric CO2 levels since the scientists who made them point out, for example, that CO2 measures are 40 ppm higher in the afternoon than in the morning, and higher on windless days compared to windy days. These are clear indications of massive contamination of CO2 measures with industrial/human sources (see my post #172 on the "It's the sun" thread). So on the one hand you are cheerleading for awesomely nonsensical paleoCO2 data massively contaminated with urban/industrial contributions... ...and on the other (here), asserting that the atmospheric CO2 data "cannot represent the global condition" when in fact it's easy to demonstrate that they do represent the global condition, since data from urban centres isn't used in assessing the atmospheric CO2 concentrations ('though they might have other uses with respect to local conditions). One needs to decide whether one is being skeptical or is instead pursuing conspiracy theories on behalf of dodgy agendas!
130959. Patrick 027 at 16:24 PM on 8 October 2008
        Climate sensitivity is low
        

        Some general info: "The Physical Science behind Climate Change Why are climatologists so highly confident that human activities are dangerously warming Earth? Members of the IPCC, the 2007 peace winner, write on climate change By William Collins, Robert Colman, James Haywood, Martin R. Manning and Philip Mote" link  "Simple Question, Simple Answer… Not" Real Climate, I have comments here (numbers of comments that were mine:) Real Climate (11,86,98,109,132,138,141) Real Climate (104,105,111) Real Climate (59,123,147,152,153,159,160,171,175,189,193,195,197,218,234,236,239,251,257,265,266,267,268(repeated an error regarding $700 billion, oops!),271,273,285,294, NOTE ALSO these comments that are not mine: 102,226 and the the responses to 81,166,201) Real Climate (9,10,11,49,50,60,138,142,161,166,170,171,175) HERE IS THE COMMENT ON THERMODYNAMICS (and some other comments): Real Climate (69,73,74,75)

        Moderator Response:

        [RH] Fixed links that were breaking page format.

130960. Patrick 027 at 11:27 AM on 8 October 2008
        Climate sensitivity is low
        Response to comment 62 (Quietman) in "It's volcanoes (or lack thereof)": "You still assume AGW is a big player and I do not. See the sensitivity thread. " No, I don't assume, I conclude. There isn't much more I could say about that, after: http://blogs.abcnews.com/scienceandsociety/2008/07/tropical-storm.html http://blogs.abcnews.com/scienceandsociety/2008/07/global-warming.html#comments http://blogs.abcnews.com/scienceandsociety/2008/09/nature-is-not-a.html (PS in the first of those, before I realized "Science and Society" deletes website addresses, I had posted some links to some RealClimate posts where I had some comments. Might go back and repost those RealClimate sites here later... I remember one was about basic thermodynamics.) Relavant to climate sensitivity and time constants, I had made some comments in the last of those three "Science and Society" sites above, where it was found: For a linearized approximation of climate behavior, in terms of global average surface temperature, with constant effective heat capacity and climate sensitivity: If the time constant is also the e-folding time for exponential decay to equilibrium (that's my understanding of the term 'time constant'): Time constant (or e-folding time) = heat capacity (average per unit area) * climate sensitivity. For example, for a climate sensitivity of 0.7 K/(W/m2) and the globally-averaged effect of the heat capacity of the top 100 m of ocean, I found an e-folding time of about 6 years. From this website, the time constant may be more like 15 years or so (for a prolonged climate forcing change, which can then penetrate below the top of the ocean), so with the same climate sensitivity, the effect heat capacity may be more like that of the top ~ 250 m of ocean (but this is only a mathematical equivalence - the warming signal would penetrate more or less deeply at different locations depending on the circulation patterns). If it turns out that 1. solar effects outside of TSI(multiplied by 0.7/4 to get climate forcing) and enhanced solar UV (I'm assuming that's taken into account in at least some models, since it is understood that a greater portion of solar variation is in UV and UV affects the upper atmosphere (stratosphere, etc.) in particular), such as magnetic effects and solar wind, 2. variations in ocean tidal forcing, it's effect on ocean circulation and mixing. 3. geomagnetic changes outside of effects of solar changes on magnetosphere 4. volcanism or whatever ... if any of these turns out to have been more important than previously judged, the conclusion would not be that AGW is not important but that the climate forcing has been bigger than it was thought and so the climate sensitivity must not be as great - OR perhaps the climate sensivity is what we thought but we have underestimated the cooling effect of our aerosol emissions... Etc. PS of 1-4 above, ... well I'm skeptical. I'm interested in learning more about 1-3, though, although I'm doubtful of the effectiveness of proposed mechanisms for 1 and 3 (though there was one article you had mentioned some time ago that looked intriguing... about variations in transmissivity of clear sky atmosphere due to electromagnetic/ionospherice/solar wind/related stuff...); for 2, I'm doubtful as to the strength of the variations over the time periods pertinent to AGW (and not clear that it was really asserted that 2 would account for some significant portion of what has been attributed to AGW forcing)
130961. Patrick 027 at 10:47 AM on 8 October 2008
        Volcanoes emit more CO2 than humans
        ... will post response at: http://www.skepticalscience.com/climate-sensitivity.htm
130962. chris at 07:10 AM on 8 October 2008
        Human CO2 is a tiny % of CO2 emissions
        Re #10 Mizimi That's a massive non-sequiter unfortunately. It also contains an essential fallacy. The 90% of the Earth's sequestered carbon ISN'T "locked up in ocean sediments"...90% of the earth's sequestered carbon was originally DERIVED from ocean sediments (and is now oil/natural gas and so on...) Of course we know very well that the evidence indicates that the system described in the graphics in the top article is more or less in balance. This refers to the short term carbon cycle which describes the recycling of non-sequestered carbon through the biosphere, as well as some elements of the longer term carbon cycle involving slow sequestration of carbon and its reintroduction to the biosphere through (largely) ocean sedimentation of carbon fixing life-forms and volcanic activity, respectively. This is readily apparent in the paleoCO2 record. In the short term (last 10000 years), atmospheric CO2 has maintained a relatively steady CO2 concentration (270 ppm +/- 10 ppm)... e.g. http://www.ipcc.ch/pdf/assessment-report/ar4/wg1/ar4-wg1-spm.pdf lower resolution data indicate that this sort of level has been in the atmosphere for the last 20-odd million years before the 20th century (i.e. 180-350 ppm; the low values occurring during glacial periods). e.g. Pearson, PN and Palmer, MR (2000) "Atmospheric carbon dioxide concentrations over the past 60 million years" Nature 406, 695-699. So that equilibrium in the short/medium term carbon cycle exists and is readily apparent. Obviously once one starts digging up and burning carbon sequestered out of the cycle for many 10's and 100's of millions of years, the equilibrium is abruptly perturbed, and as we're seeing atmospheric CO2 levels are shooting upwards. Incidentally, which "other factors" that are being "totally ignored" were you thinking of Mizimi?
130963. chris at 05:24 AM on 8 October 2008
        It's the sun
        ..sorry I meant the 9th warmest Jan-August on record. best to be accurate!
130964. chris at 05:21 AM on 8 October 2008
        It's the sun
        Re #176 Quietman Truthseeker considered that it was relevant since he (she?)bothered to write a post about it. The data from the NOAA site just wasn't related very well (perhaps Truthseeker isn't really a truth seeker!). Of course (as I said in my post) one can't assess trends by examining single months. Perhaps the relevance relates to those drip drip efforts to downplay the effects of global warming! Or perhaps the relevance is that in a year that doesn't "seem" that warm, where we've had the effects of a strong La Nina at the start of the year, and we are additionally smack at the bottom of the solar cycle (remember that the Tung and Camp paper that you have been cheerleading supposedly gives us a 0.2 oC of cooling at the solar minimum compared to the maximum), we've had the 10th warmest Jan-August on record... ...that's pretty remarkable! ...or perhaps not.....
130965. chris at 05:11 AM on 8 October 2008
        CO2 lags temperature
        Well that's good Quietman....you don't have a problem with some of the simple expectations of CO2 feedbacks as they apply under the influence of Milankovitch cycles. On the other hand it's not obvious why you consider a truism to be an assumption! It's been known since the middle of the 19th century that the earth's temperature is defined by the insolation from the sun (which gives the Earth a black body temperature near -15 oC) and the greenhouse effect arising largely from water vapour and CO2 that supplements the black body temperature by around 30 oC. That's pretty much a truism. One cannot pretend that the greenhouse effect doesn't exist! So the solar and greenhouse contributions effectively set the earth's equilibrium temperature, and stochastic and cyclical variations in the climate system (wind and ocean currents) and volcanic effects, give rise to fluctuations around the equilibrium temperature. Occasionally rather horrible impacts from extraterrestrial sources or catastrophic tectonic events generate major abrupt perturbations. But otherwise it's the sun and the greenhouse effect. ...and indeed the major independent variable with respect to the greenhouse effect is the atmnospheric CO2 (and methane somewhat, especially in the deep past) concentration, since as we all know very well, atmospheric water vapour concentrations rather passively follow the atmospheric temperature (and pressure). What did you have in mind?
130966. Quietman at 03:55 AM on 8 October 2008
        It's the sun
        Re: "6th coolest in the last 30 years vs 10th warmest in the global surface record out of 129 years" Does this have any relevance whatsoever?
130967. Quietman at 03:48 AM on 8 October 2008
        CO2 lags temperature
        Re: "Another way of thinking about this is to recognisie the truism that the earth's equilibrium temperature will fluctuate (by internal variations of the climate system) around a level that is "set" by whatever level of greenhouse gas concentrations and insolation that happens to pertain." ASSUMPTION!!!
130968. Quietman at 03:46 AM on 8 October 2008
        CO2 lags temperature
        Re: "It's a question of relative magnitudes of forcings, and the timescales for various re-equilibration to changes in forcings" YES!!!
130969. Quietman at 03:45 AM on 8 October 2008
        CO2 lags temperature
        Re: "But isn't that exactly what's expected if the CO2 rise and fall is itself a feedback from the primary (Milnkovitch-induced) warming? " YES!!!
130970. chris at 01:16 AM on 8 October 2008
        It's the sun
        Three problems wth that Truthseeker: (i) one can't presume trends by looking at data from single months! (ii) I doubt anyone would have stated that the La Nina was the sole cause of a period of relative cooling in a warming world. We're smack at the bottom of the solar cycle, so one doesn't expect record breaking temperatures for a while (the next major El Nino in a few years is likely to give us the new record). (iii) Your interpretation seems somewhat odd anyway. From the data you've linked to we can see that: a. August 2008 is the 10th warmest in the global surface record out of 129 years. Clearly therefore there can only be 9 Augusts warmer than it in the last 30 years (not 24 as you intimate). b. June to August 2008 is the 9th warmest summer in the global surface record of 129 years. Clearly therefore there can only be 8 summers warmer than it in the last 30 years. c. and so on (it's the 9th warmest Jan-August period on record)
130971. chris at 00:56 AM on 8 October 2008
        CO2 lags temperature
        #32 and #43 You each dismiss the possibility of feedbacks to CO2-induced warming, without really explaining your problem. In each case this seems to relate to the observation that during Milankovitch cycles associated with glacial-interglacial-glacial transitions, the earth's temperature drops while atmospheric CO2 levels remain high for a while. But isn't that exactly what's expected if the CO2 rise and fall is itself a feedback from the primary (Milnkovitch-induced) warming? Obviously atmospheric CO2 levels will lag behind temperature levels on both the rising and falling parts of the cycle. It's a question of relative magnitudes of forcings, and the timescales for various re-equilibration to changes in forcings. If the solar (insolation) dominates (as we consider to be the case), then it will "dominate" the effects of CO2, feedbacks and all. We could make an analogy with the day night cycle. Right now atmospheric CO2 levels are the highest they've been for many millions of years and the Earth is warming. However last night while CO2 levels were extraordinarily high (382 ppm or whatever the current value is), when the sun went down, it got a bit cooler. In fact as the air cooled last night some of the water vapour precipitated out and it rained.... Now that scenario doesn't indicate that raised atmospheric CO2 doesn't have an associated positive water vapour feedback. It clearly does (we can measure this in the real world). It just means that the insolation effect dominates the CO2 effect, feedbacks and all. The associated thing that needs to be considered is the timescale of the effects. The CO2 feedback to warming is very slow (and likewise to cooling). Once atmospheric CO2 levels are raised they stay that way for a long time. But both the warming effect of CO2 and its water vapour feedback are a consequence of an interaction with the insolation. If the insolation drops, then the greenhouse effect of the raised CO2 and water vapour will drop immediately. And a reduction in the feedbacks will follow on different timescales. The water vapour feedback will drop quickly (days to months following reduced warming resulting from reduced insolation)....the atmospheric CO2 levels will remain high for a very long time following the temperature drop and will drop much, much more slowly in response to the cooling. In fact in the cooling part of the cycle the secondary feedback on the warming cycle (water vapour following the CO2 rise) will seem to reduce much more quickly than the primary feedback (the raised atmospheric CO2). Another way of thinking about this is to recognisie the truism that the earth's equilibrium temperature will fluctuate (by internal variations of the climate system) around a level that is "set" by whatever level of greenhouse gas concentrations and insolation that happens to pertain. However the rates at which these equilibria are attained depends on the rates at which various feedbacks respond. So what might seem to be anomalous phenomena, are not unexpected at all....
130972. TruthSeeker at 00:24 AM on 8 October 2008
        It's the sun
        For thoes of you who said that recent cooling was due to la Nina and that the trend would end in the second half of the year. Take a look at this NOAA data, it tends to prove you wrong. It looks like this August is the 6th coolest in the last 30 years. http://www.ncdc.noaa.gov/oa/climate/research/2008/aug/global.html#year-to-date
130973. chris at 21:26 PM on 7 October 2008
        Climate sensitivity is low
        Re #2 GMB You've got that wrong. Schwartz is the one that is using very short time series (largely 40-50 year periods in the 20th century) to estimate his "sensitivity". Your comments about CO2 and its relation to temperature change during ice age cycle transitions are not relevant in the manner that you might wish your capitalized phrase to insinuate. There are two essential methods of determining climate sensitivity in relation to real world measurements (a third would be to use a completely theoretical analysis). These are: (i) Determination of the relationship between equilibrium temperature and atmospheric CO2 from paleodata. This is in principle preferable since the analyis can be made with respect to "equilibrium" situations. i.e. since the climate sensitivity relates explicitly to the earth's surface temperature rise AT EQUILIBRIUM per doubling of atmospheric CO2, this should give us the more accurate analysis. Unfortunately there are uncertainties due to the uncertainties in the paleodata. (ii) The second is to eschew equilibrium measurements and monitor the temperature response to enhanced greenhouse forcing as the temperature rises TOWARDS it's new equilibrium temperature. Simplistically (and Schwartz has used this simplisitic approach) one considers that there will be a hyperbolic rise to a new equilibrium temperature. A regular hyperbola is characterized by its MAXIMUM VALUE at equilibrium (in this case the climate sensitivity) and a TIME CONSTANT that characterises the rate at which equilibrium is achieved. Obviously if the maximum (equilibrium) hasn't been reached one needs to estimate the parameters defining the "shape" of the response. Schwartz makes several errors and unrealistic asumptions that are outlined in some of the links in John's top post. He uses detrended time series of 20th century temperature trends, makes an unrealistic assumption that the climate system response can be characterised by a single exponential (one time constant), and comes up with a time constant of 5 years. Unfortunately his detrending smooths out the longer time constants that alomst certainly apply to the system. In essence he's attempting to pursue the conclusion that we've had much of the warming due to the increased forcing already. However if more realistic multiple time constant series are used (i.e. his data are heavily biased towards the very rapid time constant(s) for atmospheric warming in response, for example, to volcanic eruptions, the less rapid time constant for ocean surface warming and so on), his climate sensitivty value increase rather markedly. And since the oceans are a repository of thermal inertia limit a rapid re-equilibration of the earth's surface temperature, it's rather more valid to include long time constants when considering the EQUILIBRIUM response of the Earth's temperature to greenhouse warming. In fact if a rather more realistic time constant of 15 years is used, Schwartz's climate sensitivty becomes near 3 oC per doubling of atmospheric CO2, pretty much equivalent to all of the other published data. It's pretty clear from reading Schwartz's paper that he realises that his analysis is extremely oversimplified. I'm not sure what you consider to be the relevance of the fact that warming leads rising atmospheric CO2 during the glacial-interglacial transitions for this analysis. The aim of all of these analysis is to determine the best estimate of the climate sensitivity to rising atmospheric CO2 levels. The source of the rise in atmospheric CO2 is not really relevant for these analyses... PS: Having read what I've written before posting it, I realize I've said quite a bit of what John Cook has already said in his top article !
130974. Quietman at 19:03 PM on 7 October 2008
        Volcanoes emit more CO2 than humans
        Patrick You still assume AGW is a big player and I do not. See the sensitivity thread.
130975. chris at 10:59 AM on 7 October 2008
        Temp record is unreliable
        Re #30-32 These questions have been addressed fairly conclusively by the science. (i) You are correct (Tree) that the earth took many millions of years to sequester atmospheric CO2 in the form of fossil fuels (oil, gas, coal, shale and so on). Around 4000 billion tons of carbon is "stored" in this manner, and it's taken around 600 million years to do this. In the last 100 years we've released around 500 billion tons of this carbon back into the atmosphere, of which around 200 billion tons has remained there (around 300 billion tons has been absorbed by the oceans and terrestrial environment). see for example: http://www.physicalgeography.net/fundamentals/9r.html (ii) It's very clear that volcanic activity is on a miniscule scale with respect to our massive release of carbon dioxide. It's easy to demosstrate this. If one examines the high resolution atmospheric CO2 record over the last 1000 years, for example, one can see that the atmospheric CO2 levels remain rather constant over the period up to around the mid to late 19th century and rise massively in response to our emissions. The absence of significant activity from volcanoes can be observed by the absense of jumps in the atmospheric CO2 record as a result of the truly hummungous volcanoes of the last 1000 years (e.g. Santorini, Krakatoa and Tambora). Volcanic activity results in the release of something a ggod bit less than 1% of our current industrial emissions. see, for example, the high resolution atmospheric CO2 record compiled on page 3 of the IPCC summary for policymakers: http://www.ipcc.ch/pdf/assessment-report/ar4/wg1/ar4-wg1-spm.pdf (see page 3) (iii) Heat from tectonic activity is trivial with respec to greenhouse gas warming. This is one of those fallacious "arguments" that is doing the rounds! The practicioners avoid the three pertinent points. These are: (i) is there any evidence for enhanced tectonic activity during the period of very large warming (especially last 30-odd years)? After all tectonic activity has been occurring for millions of years. Has it suddenly intensified? Evidence please! (ii) how can it be that the areas of which major tectonic activity show little match to areas of temperature increase? For example Iceland is one of the most tectonically active regions on earth. However it is one of the few places on earth that has undergone a tiny bit of COOLING during the period of global warming: e.g. data on the scale and location of Arctic warming over the last 50 years from the Colorado University Arctic research center: http://arctic.atmos.uiuc.edu/CLIMATESUMMARY/2003/IMAGES/annual.1954-2003.tchange.png (iii) the heat released by undersea tectonic activity is around that of the geothermal background. This is around 0.1% of the heat energy from solar/greenhouse activity. e.g. according to Jeff Severinghaus of the Scripps Institution of Oceanography "... the average heat added from volcanoes to the ocean is of order 0.1 Watt per square meter. But the heat added (or removed) to the ocean from the sun and atmosphere is of order 100 Watt per square meter. So it is very hard for volcanoes to compete." So it's not just a question of showing that tectonic activity on the ocean bottom is significant with respect to warming (the evidence indicates it isn't), but of showing that this activity has increased in the last several decades to an extent that can have contributed to warming (the evidence indicates that it hasn't)...
130976. chris at 09:48 AM on 7 October 2008
        It's the sun
        Re #160 Wondering Aloud You state rather cryptically that "The satellite data that was supposed to prove a positive feedback from CO2 causing increased water vapor in fact show the opposite." but that doesn't seem to accord with the facts. The expectation is that as the atmosphere warms, the air will support somewhat higher levels of water vapour (since warm air has a higher saturation point for water vapour than colder air). This results in a feedback warming due to the greenhouse properties of atmospheric water vapour. So has the water vapour concentration increased during the period of massive increase in atmospheric CO2, in response to CO2-driven warming? According to the science the answer seems to be yes (as opposed to your unattributed "no"): Soden BJ et al. (2005) "The radiative signature of upper tropospheric moistening" Science 310, 841-844. Abstract: "Climate models predict that the concentration of water vapor in the upper troposphere could double by the end of the century as a result of increases in greenhouse gases. Such moistening plays a key role in amplifying the rate at which the climate warms in response to anthropogenic activities, but has been difficult to detect because of deficiencies in conventional observing systems. We use satellite measurements to highlight a distinct radiative signature of upper tropospheric moistening over the period 1982 to 2004. The observed moistening is accurately captured by climate model simulations and lends further credence to model projections of future global warming." Santer BD et al (2007) "Identification of human-induced changes in atmospheric moisture content" Proc. Natl. Acad. Sci. USA 104 15248-15253. Abstract: "Data from the satellite-based Special Sensor Microwave Imager (SSM/I) show that the total atmospheric moisture content over oceans has increased by 0.41 kg/m(2) per decade since 1988. Results from current climate models indicate that water vapor increases of this magnitude cannot be explained by climate noise alone. In a formal detection and attribution analysis using the pooled results from 22 different climate models, the simulated "fingerprint" pattern of anthropogenically caused changes in water vapor is identifiable with high statistical confidence in the SSM/I data. Experiments in which forcing factors are varied individually suggest that this fingerprint "match" is primarily due to human caused increases in greenhouse gases and not to solar forcing or recovery from the eruption of Mount Pinatubo. Our findings provide preliminary evidence of an emerging anthropogenic signal in the moisture content of earth's atmosphere." Rind D et al (1991) "Positive Water-Vapor Feedback In Climate Models Confirmed By Satellite Data" Nature 349, 500-503. Abstract: "Chief among the mechanisms thought to amplify the global climate response to increased concentrations of trace gases is the atmospheric water vapour feedback. As the oceans and atmosphere warm, there is increased evaporation, and it has been generally thought that the additional moisture then adds to the greenhouse effect by trapping more infrared radiation. Recently, it has been suggested that general circulation models used for evaluating climate change overestimate this response, and that increased convection in a warmer climate would actually dry the middle and upper troposphere by means of associated compensatory subsidence1. We use some new satellite-generated water vapour data to investigate this question. From a comparison of summer and winter moisture values in regions of the middle and upper troposphere that have previously been difficult to observe with confidence, we find that, as the hemispheres warm, increased convection leads to increased water vapour above 500 mbar in approximate quantitative agreement with the results from current climate models. The same conclusion is reached by comparing the tropical western and eastern Pacific regions. Thus, we conclude that the water vapour feedback is not overestimated in models and should amplify the climate response to increased trace-gas concentrations." Allan RP and Soden BJ (2008) "Atmospheric warming and the amplification of precipitation extremes" Science 321, 1481-1484. Abstract: "Climate models suggest that extreme precipitation events will become more common in an anthropogenically warmed climate. However, observational limitations have hindered a direct evaluation of model- projected changes in extreme precipitation. We used satellite observations and model simulations to examine the response of tropical precipitation events to naturally driven changes in surface temperature and atmospheric moisture content. These observations reveal a distinct link between rainfall extremes and temperature, with heavy rain events increasing during warm periods and decreasing during cold periods. Furthermore, the observed amplification of rainfall extremes is found to be larger than that predicted by models, implying that projections of future changes in rainfall extremes in response to anthropogenic global warming may be underestimated." Note that this effect (atmospheric temperature-induced feedback in atmospheric water vapour concentrations) can also be observed as a result of atmospheric cooling, for example due to rapid volcanic eruption-induced cooling: Soden BJ et al. (2002) "Global cooling after the eruption of Mount Pinatubo: A test of climate feedback by water vapor" Science 296,727-730 Abstract: "The sensitivity of Earth's climate to an external radiative forcing depends critically on the response of water vapor. We use the global cooling and drying of the atmosphere that was observed after the eruption of Mount Pinatubo to test model predictions of the climate feedback from water vapor. Here, we first highlight the success of the model in reproducing the observed drying after the volcanic eruption. Then, by comparing model simulations with and without water vapor feedback, we demonstrate the importance of the atmospheric drying in amplifying the temperature change and show that, without the strong positive feedback from water vapor, the model is unable to reproduce the observed cooling. These results provide quantitative evidence of the reliability of water vapor feedback in current climate models, which is crucial to their use for global warming projections." and so on....
130977. chris at 09:28 AM on 7 October 2008
        It's the sun
        Re #160 Wondering Aloud (and many others) This thread shows a breathtaking absence of skepticism! It's rather awesome the nonsense that some people are willing to swallow in pursuit of a conspiracy theory. Let's look at the "paleorecord" ("water vapour feedback" in following post) THE PALEORECORD for CO2: The scientific analysis of paleoCO2 measurements and paleotemperature measurements are highlighted in numerous reviews and articles that are appended at the bottom of the post. These show a rather strong coupling of paleoCO2 and paleotemperature. Some posters are exercised over historical records described by a German schoolteacher (Beck). They apparently show CO2 measurements that go up and down in an extraordinary manner. Mr Beck assures us of the precision of historical measures of CO2 during the last 180 years. Why might we be skeptical of this weird data with its absolutely massive rapid jumps and falls in CO2? Here's some pretty obvious reasons for skepticism: (i) Beck assures us that the measures were precise (1-3%). But we're really more interested in their ACCURACY with respect to global atmospheric CO2 concentrations. We know that a large proportion of the measurements were made in individual scientists laboratories in cities (Paris, Kew gardens London, Belfast, Clermont Ferrand, Copenhagen, Vienna, Frankfurt, Giessen, Bern, Poona India, Rostock in Denmark, Ames Iowa...etc. etc. etc.). We know that if one goes to a city today and makes CO2 measurements in the air in our city laboratories, large variations in CO2 levels will be recorded, with high values relative to the true atmospheric concentrations. Just as in the 19th and early 20th century, we’re surrounded in cities by CO2 sources (pretty much all transport and heat/cooling generation). See for example point (iii) below. Competent scientists understand the essential difference between PRECISION and ACCURACY. A local CO2 measure may be beautifully precise but wildly inaccurate with respect to the global atmospheric CO2 value. That's where Becks "analysis" is likely to fool the unskeptical. (ii) We can look at this problem of accuracy in more detail by focusing on the individual series of measurements highlighted by Beck. For example, Beck highlights W. Kreutz’s series of very high CO2 measures in 1939/40. These measurements were made just S of the city of Giessen not far from the railway station. Beck fails to point out that Kreutz’s values differ by an astonishing 40 ppm between morning and afternoon (in other words measured atmospheric CO2 values are 40 ppm higher in the afternoons compared to the mornings), that atmospheric CO2 is much lower on windy days compared to windless days and so on. This is all outlined in Kreutz’s paper on the subject (translation available here: http://www.biokurs.de/treibhaus/literatur/kreutz/Kreutz_english.pdf). Clearly atmospheric CO2 measurements in, or near, urban centres give massively high CO2 values however precisely they are measured, the CO2 levels will rise dramatically in the afternoons when everyone and their machines are active, and on windless days when generated CO2 isn’t dispersed, measured CO2 levels will be higher still. That’s all pretty obvious. A skeptic might be expected to notice these rather obvious facts…. It's fascinating that Kreutz identified and postulated that some of the high values and extreme variations in atmospheric CO2 levels in his measurements were due to soil sources and industrial sources...sadly, and rather typically, the data of the honest and comptetent Kreutz has been usurped to support a creepy agenda by the dishonest... (iii) It takes an effort to make truly accurate and unperturbed atmospheric CO2 measurements. Some early practitioners made this effort. Jules Reiset, for example, in the late 19th century, developed a methodology for CO2 measurements taken on the windy Atlantic coast, far from urban centres, and determined values rather similar to those measured in contemporaneous ice cores (around 190-200 ppm in the 1890’s). We can be rather more confident in the ACCURACY of Reiset’s measurements since he (unlike pretty much all other measurers of CO2 in the 19th and early 20th century) identified the clear signature of seasonal variation due to plant growth and decay dominated by the N. hemisphere flora. (iv) We have been observing atmospheric CO2 levels with extraordinary precision and accuracy since the late 1950’s from the Manua Loa observatory, as well as dozens of other locations around the world. Atmospheric CO2 levels simply do not undergo massive jumps of up to 100 ppm over a few years. It beggers belief that CO2 sources could release and reabsorb extraordinarily massive amounts of CO2 (see #4 just below) during a period when we weren’t actually monitoring CO2 levels very well, and yet just when we started to monitor levels with considerable ACCURACY and PRECISION, atmospheric levels immediately stopped jumping around wildly. A skeptic would be inclined to doubt the accuracy of early measurements from urban centres. (v) According to Beck atmospheric CO2 rose and fell with massive jumps/falls of around 100 ppm or more during the early and mid 19th century, and the 1930’s-40s’. Since the pre-industrial level of atmospheric CO2 (around 180 ppm) is rather similar to the entire repository of CO2 in terrestrial plantlife, the assumption is that these 100 ppm jumps/falls over a few years are associated with the rapid loss and regrowth of around half the entire plant biomass on earth? Did we really lose terrestrial plant matter equivalent to the entire Amazon and African rainforests and much of Asia during a few short years, and have these regrow again in a few years afterwards? No. We know this can’t have happened during the 1930’s and 40’s since we were monitoring the terrestrial biosphere already during these years. (vi) we have rather abundant ice core measures of atmospheric CO2. Since these measures of atmospheric CO2 locked within ice are in regions far from centres of CO2 sources (urban/plant growth) they are rather reliable measures of unperturbed and well-mixed atmospheric CO2. These show rather constant levels of atmospheric CO2 near 177 (+/- around 6 ppm) during the period from 1000 AD to the mid 19th century, and then slow gradual rises that merge in the late 1950’s with the directly measured Manua Loa and other modern CO2 measures. One can certainly argue that the ice core measures are averaged, since deposited snow in ice sheets doesn’t compact and trap ice for several years after deposition, such that there is exchange with the atmosphere for some time until the atmospheric sample becomes sealed within bubbles in solid ice. However one can’t really postulate massive rise of atmospheric CO2 apparently to value as high as 470 ppm during the late 1930’s and 1940’s, without some rising of ice core CO2 levels that match this time period. Even if the ice core CO2 values are averaged over several years, high CO2 values would have to appear for this period in the ice cores. They don’t. and so on…. ---------------------------------------------- Here's some of the abundant data that indicates a rather close coupling of paleoCO2 and paleotemperature measurements right through the last 500 million years. D.L. Royer (2006) "CO2-forced climate thresholds during the Phanerozoic" Geochim. Cosmochim. Acta 70, 5665-5675. (this is a review compiles much of the published data) Even more recent studies supplement the information in Royers compilation and cover additional periods with new data sets right through the past several hundreds of millions of years: R.E. Carne, J.M. Eiler, J. Veizer et al (2007) "Coupling of surface temperatures and atmospheric CO2 concentrations during the Palaeozoic era" Nature 449, 198-202 W. M. Kurschner et al (2008) “The impact of Miocene atmospheric carbon dioxide fluctuations on climate and the evolution of the terrestrial ecosystem” Proc. Natl. Acad. Sci. USA 105, 499-453. D. L. Royer (2008) “Linkages between CO2, climate, and evolution in deep time” Proc. Natl Acad. Sci. USA 105, 407-408 Zachos JC (2008) “An early Cenozoic perspective on greenhouse warming and carbon-cycle dynamics” Nature 451, 279-283. Doney SC et al (2007) “Carbon and climate system coupling on timescales from the Precambrian to the Anthropocene” Ann. Rev. Environ. Resources 32, 31-66. Horton DE et al (2007) “Orbital and CO2 forcing of late Paleozoic continental ice sheets” Geophys. Res. Lett. L19708 (Oct. 11 2007). B. J. Fletcher et al. (2008) “Atmospheric carbon dioxide linked with Mesozoic and early Cenozoic climate change” Nature Geoscience 1, 43-48.
130978. chris at 05:21 AM on 7 October 2008
        Solar cycles cause global warming
        Re #3 That's incorrect. Tung and Camp derive a value for the earth's climate sensitivity to raised CO2 that is completely independent of the so-called "IPCC's accepted sensitivity". That's the whole point of their work! They analyze the solar cycle contribution to warming and (according to their analysis) derive an INDEPENDENT measure of the climate sensitivity. Their value is (see equation 2 on line 379 of their manuscript): 2.3 oK < DeltaT(2xCO2) < 4.1 oK In other words according to Tung and Camp, the Earth warms by around 3 oC (plus/minus a bit) for each doubling of atmospheric CO2 concentration. The fact that this value is pretty much in line with all of the other scientific analyses of climate sensitivity (as compiled by the IPCC) is interesting and may be taken as further evidence of a consistent arrival at the climate sensitivity using a number of different methods. But it is an ENTIRELY INDEPENDENT measure and doesn't assume anything whatsoever about "the IPCC"! That's pretty straightforward...
130979. TruthSeeker at 04:15 AM on 7 October 2008
        It's the sun
        You all said that the begining of the year was cooler due to la nina, and that this coolness trend would end July - August. However, August was cooler than the last few years via NOAA. Check the link: http://www.ncdc.noaa.gov/img/climate/research/2008/aug/glob-aug-pg.gif What do you all have to say about this?
130980. Quietman at 01:08 AM on 7 October 2008
        Water vapor is the most powerful greenhouse gas
        Has Global Warming Research Misinterpreted Cloud Behavior? ScienceDaily (June 12, 2008) ["Unfortunately, so far we have been unable to figure out a way to separate cause and effect when observing natural climate variability. That's why most climate experts don't like to think in terms of causality, and instead just examine how clouds and temperature vary together.] - Spencer
130981. chris at 20:45 PM on 6 October 2008
        Climate's changed before
        That's a very odd notion. Odd in two respects. First the enhanced atmospheric water vapour that follows enhanced greenhouse atmospheric warming has been directly measured [*] and some of the consequences with respect to surface humidity and precipitation patterns are already identified in the real world [**]. Secondly, because the "gravity" notion raised in the dodgy website you linked to is a nonsense. Water vapor that partitions in the atmosphere does so according to atmospheric pressure and temperature. As the temperature of the atmosphere rises so does the water vapour concentration. Is this effect countered by gravity? Not to any significant degree. Atmospheric water exists in the atmosphere in the form of individual water molecules. The gravitational force acting on these molecules is extremely small and is opposed by the kinetic energy of the water molecules provided by the ambient thermal energy. It's only if the atmosphere cools a bit and the water vapour concentration rises above the saturation point, that gravity takes a significant macroscopic hold. Then water molecules "aggregate", the water vapour condenses, and gravity then has an effect (it rains!). So not only is the website trying to sell a ludicrous notion, but it's premise is contradicted by real world measurements (see [*] and [**] below. [*] e.g.: Soden BJ et al. (2005) "The radiative signature of upper tropospheric moistening" Science 310, 841-844. Abstract: "Climate models predict that the concentration of water vapor in the upper troposphere could double by the end of the century as a result of increases in greenhouse gases. Such moistening plays a key role in amplifying the rate at which the climate warms in response to anthropogenic activities, but has been difficult to detect because of deficiencies in conventional observing systems. We use satellite measurements to highlight a distinct radiative signature of upper tropospheric moistening over the period 1982 to 2004. The observed moistening is accurately captured by climate model simulations and lends further credence to model projections of future global warming." Santer BD et al (2007) "Identification of human-induced changes in atmospheric moisture content" Proc. Natl. Acad. Sci. USA 104 15248-15253. Abstract: "Data from the satellite-based Special Sensor Microwave Imager (SSM/I) show that the total atmospheric moisture content over oceans has increased by 0.41 kg/m(2) per decade since 1988. Results from current climate models indicate that water vapor increases of this magnitude cannot be explained by climate noise alone. In a formal detection and attribution analysis using the pooled results from 22 different climate models, the simulated "fingerprint" pattern of anthropogenically caused changes in water vapor is identifiable with high statistical confidence in the SSM/I data. Experiments in which forcing factors are varied individually suggest that this fingerprint "match" is primarily due to human caused increases in greenhouse gases and not to solar forcing or recovery from the eruption of Mount Pinatubo. Our findings provide preliminary evidence of an emerging anthropogenic signal in the moisture content of earth's atmosphere." Rind D et al (1991) "Positive Water-Vapor Feedback In Climate Models Confirmed By Satellite Data" Nature 349, 500-503. Abstract: "Chief among the mechanisms thought to amplify the global climate response to increased concentrations of trace gases is the atmospheric water vapour feedback. As the oceans and atmosphere warm, there is increased evaporation, and it has been generally thought that the additional moisture then adds to the greenhouse effect by trapping more infrared radiation. Recently, it has been suggested that general circulation models used for evaluating climate change overestimate this response, and that increased convection in a warmer climate would actually dry the middle and upper troposphere by means of associated compensatory subsidence1. We use some new satellite-generated water vapour data to investigate this question. From a comparison of summer and winter moisture values in regions of the middle and upper troposphere that have previously been difficult to observe with confidence, we find that, as the hemispheres warm, increased convection leads to increased water vapour above 500 mbar in approximate quantitative agreement with the results from current climate models. The same conclusion is reached by comparing the tropical western and eastern Pacific regions. Thus, we conclude that the water vapour feedback is not overestimated in models and should amplify the climate response to increased trace-gas concentrations." [**] e.g.: Zhang XB (2007) "Detection of human influence on twentieth-century precipitation trends" Nature 448, 461-465. Abstract: "Human influence on climate has been detected in surface air temperature(1-5), sea level pressure(6), free atmospheric temperature(7), tropopause height(8) and ocean heat content(9). Human-induced changes have not, however, previously been detected in precipitation at the global scale(10-12), partly because changes in precipitation in different regions cancel each other out and thereby reduce the strength of the global average signal(13-19). Models suggest that anthropogenic forcing should have caused a small increase in global mean precipitation and a latitudinal redistribution of precipitation, increasing precipitation at high latitudes, decreasing precipitation at sub-tropical latitudes(15,18,19), and possibly changing the distribution of precipitation within the tropics by shifting the position of the Intertropical Convergence Zone(20). Here we compare observed changes in land precipitation during the twentieth century averaged over latitudinal bands with changes simulated by fourteen climate models. We show that anthropogenic forcing has had a detectable influence on observed changes in average precipitation within latitudinal bands, and that these changes cannot be explained by internal climate variability or natural forcing. We estimate that anthropogenic forcing contributed significantly to observed increases in precipitation in the Northern Hemisphere mid-latitudes, drying in the Northern Hemisphere subtropics and tropics, and moistening in the Southern Hemisphere subtropics and deep tropics. The observed changes, which are larger than estimated from model simulations, may have already had significant effects on ecosystems, agriculture and human health in regions that are sensitive to changes in precipitation, such as the Sahel." Allan, R P & Soden, B J (2008) Atmospheric warming and the amplification of precipitation extremes" Science 321, 1481-1484. Abstract: "Climate models suggest that extreme precipitation events will become more common in an anthropogenically warmed climate. However, observational limitations have hindered a direct evaluation of model- projected changes in extreme precipitation. We used satellite observations and model simulations to examine the response of tropical precipitation events to naturally driven changes in surface temperature and atmospheric moisture content. These observations reveal a distinct link between rainfall extremes and temperature, with heavy rain events increasing during warm periods and decreasing during cold periods. Furthermore, the observed amplification of rainfall extremes is found to be larger than that predicted by models, implying that projections of future changes in rainfall extremes in response to anthropogenic global warming may be underestimated."
130982. Patrick 027 at 15:36 PM on 6 October 2008
        Volcanoes emit more CO2 than humans
        Quietman, "Re: 3 The pole remains in the Arctic yes but the amount of direct sunlight changes with the angle of attack." Yes - this much is a widely understood aspect of Milankovitch cycles. "Re: 2 I disagree here. But as with any hypothesis there is room for doubt. This is under study so I am content to wait on the outcome." If you could find articles which specify changes in time (of geologic activity, aside from major eruptions above water, of course) correlated with any climate changes on the scale of years to millenia, I'd very much like to see it. Clarification - as I recall now, there was some speculation about possible temporal changes in geothermal heating of ice at two locations - somewhere in northern Greenland, and somewhere in West Antarctica. In each case it appeared to be only speculation, though. And I don't think those could have enough regional or global significance to account for much of recent climate changes. (With all the volcanos in the world, certainly a few could just happen to change just as anthropogenic emissions are becoming a big player, but it would seem quite a coincidence if enough volcanos in the right areas happened to change activity to have regional and global climatic significance at this time and yet not for some longer period of time prior to now (as inferred by paleoclimatic records and ice sheet conditions, etc.))
130983. Quietman at 13:00 PM on 6 October 2008
        Does Urban Heat Island effect add to the global warming trend?
        any s/b and
130984. Quietman at 12:57 PM on 6 October 2008
        Does Urban Heat Island effect add to the global warming trend?
        Philippe You are missing the point that I was trying to make. By calling this "Global Warming" instead of "Climate Change" the natural reaction for people unaffected is "what warming?" any there are obviously a lot of people in this category. I have heard it called "Climate Shift" also. Shift or Change describes what is happening much better than Global Warming and is accurate. Global means all, the entire planet. But it is not all, not the entire planet and this causes a psycological rejection of the concept.
130985. Philippe Chantreau at 11:13 AM on 6 October 2008
        Does Urban Heat Island effect add to the global warming trend?
        Quietman, I have lived in the Alps and I have seen significant difference in the ski season: duration, accumulation, altitude making a ski area viable etc... Wine growers in England do not need news to tell the difference. There are many more examples opposite to your experience. I'm not sure that having more faith in individual anecdotal reports than in observers and their equipment is necessarily wise.
130986. Adamski at 08:45 AM on 6 October 2008
        Climate's changed before
        Very interesting read here...haven't heard anything about water vapour feedback yet. Enlighten me if what i say is wrong but are the IPCC models flawed in that their water vapour feedback element is missing out on a rather unavoidable factor in gravity. Douglas Hoyt discusses here http://www.warwickhughes.com/hoyt/wvfeedback.htm about how overestimated the water vapour feedback is in the IPCC models. I take the side of the devil's advocate and say that it seems the IPCC has jumped on a bandwagon and is trying to make it work their way...but it isn't.
130987. Quietman at 04:50 AM on 6 October 2008
        Is Antarctic ice melting or growing?
        DB2 Re: "(a warmer world is also a more humid world)" This is something that I have seen (and measured when I was still working). And warm+humid+CO2=better and faster plant growth (which is something I have taken personal notice of even though it has not been any warmer than normal).
130988. Quietman at 04:41 AM on 6 October 2008
        Volcanoes emit more CO2 than humans
        Patrick Much better, thank you. Re: 1 Magnetic orientation for birds etc. may simply be lines of force rather than a true polarity orientation. A reversal likely has little effect but shift does to some extent, I would not expect extinctions however. Re: 2 I disagree here. But as with any hypothesis there is room for doubt. This is under study so I am content to wait on the outcome. Re: 3 The pole remains in the Arctic yes but the amount of direct sunlight changes with the angle of attack. Re: 4 I am uncertain of this, which is why I am here.
130989. Quietman at 04:26 AM on 6 October 2008
        Does Urban Heat Island effect add to the global warming trend?
        PPS But photographs of the Arctic and Antarctic do tell a story.
130990. Quietman at 04:25 AM on 6 October 2008
        Does Urban Heat Island effect add to the global warming trend?
        PS Measurements differ by point and instrumentation. It is a large planet and I have little faith in the observers or the designer's of their equipment.
130991. Quietman at 04:22 AM on 6 October 2008
        Does Urban Heat Island effect add to the global warming trend?
        chris That at least makes sense. But personal anecdotes based on the known freezing point of water are indeed relavent. The reason so many people do not believe in GW is infact that it isn't global. They see zero warming. I have yet to live in an area that has warmed other than NJ where it was noticable close to NYC. Here in PA there has not been any warming trend. The only way I know it's actually warming is from reading the news on the web. It is a perception issue for most people.
130992. Patrick 027 at 10:12 AM on 5 October 2008
        Volcanoes emit more CO2 than humans
        ... aside from that: 1. Unclear that recent changes in Earth's magnetic field are anything unusual over the same time period in which recent climate changes are unusual. (**PS I'd be curious to see if the previous changes in magnetic field, either in strength of dipole or actual reversals, correspond in any significant way with the paleoclimatic record, or anything else. One would think it could affect some species (birds, turtles?), though there is no evidence of enhanced extinction rates during reversals, as far as I know). 2. While new discoveries are made about submarine volcanic activity, there hasn't been a discovery of temporal changes in this, either significantly correlated to ENSO or other climate variability, or to global warming, and the same for volcanic activity in general - (except perhaps for the going into and out of a ~quiet period with respect to explosive volcanism above water, which wouldn't explain global warming of the last 100 years but apparently has influence (But not control) over ENSO). 3. As far as I know, the torques on Earth that contribute to two of the Milankovitch cycles do not result in true polar wander - the rotational axis changes orientation but the whole body of the Earth shifts with it, so the North pole remains in the Arctic over such cycles. 4. anthropogenic greenhouse forcing may be a little less than 2 % of the total greenhouse 'forcing' (including water vapor and clouds), but the small size of that proportion may not mean what some may think; a total forcing (greenhouse + albedo) that in terms of globally averaged radiative forcing would be somewhere between 3 % and 5 % of the same total greenhouse 'forcing' accounts for the global warming between the last ice age and preindustrial climate.
130993. DB2 at 09:38 AM on 5 October 2008
        Is Antarctic ice melting or growing?
        A net loss of 25 Gt per year is a lot better than the 150 of Velicogna. It is true that the models predict over the course of this century that the deposition in Antarctica will be larger than the melting (a warmer world is also a more humid world).
130994. chris at 08:15 AM on 5 October 2008
        Is Antarctic ice melting or growing?
        It's worth pointing out that Wingham et all's analysis referred to in post #3 covers only 72% of Antarctica. In fact in a more recent review Wingham and Shepherd conclude that there is a net mass loss from Antarctica, and that these are dominated by ice dynamics at the continental margins: A. Shepherd and D. Wingham (2007) "Recent Sea-Level Contributions of the Antarctic and Greenland Ice Sheets" Science 315, 1529-1532. http://www.sciencemag.org/cgi/content/abstract/315/5818/1529 e.g. they state: "It is reasonable to conclude that, today, the EAIS (East Antarctic Ice Sheet) is gaining some 25 Gt year–1, the WAIS (West AIS) is losing about 50 Gt year–1, and the GIS (Greenland) is losing about 100 Gt year–1. These trends provide a sea-level contribution of about 0.35 mm year–1, a modest component of the present rate of sea-level rise of 3.0 mm year–1. Because 50 Gt year–1 is a very recent contribution, the ice sheets made little contribution to 20th-century sea-level rise. However, what has also emerged is that the losses are dominated by ice dynamics. Whereas past assessments (47) considered the balance between accumulation and ablation, the satellite observations reveal that glacier accelerations of 20 to 100% have occurred over the past decade. The key question today is whether these accelerations may be sustained, or even increase, in the future." The latter really is the key question. No one is particulary concerned about the possibility of massive Antarctic melt, and so far (as Shepherd and Wingham indicate) the losses are marginal....in my understanding it's generally been assumed that snow deposition at the high altitude central regions will more or less balance surface melt/glacier discharge at the margins. However the more vulnerable West Antarctic Ice Sheet has the potential to raise sea levels considerably if a significant melt occurred there.
130995. DB2 at 07:21 AM on 5 October 2008
        Is Antarctic ice melting or growing?
        Here is another approach to Antarctic ice measurements by Wingham et al. www.cpom.org/research/djw-ptrsa364.pdf They use satellite radar altimetry to determine the ice thickness for the 11 years from 1992 to 2003, which show the ice sheet growing at 5mm per year. They then use density estimates and arrive at a net increase in mass of 27 Gt per year.
130996. chris at 06:56 AM on 5 October 2008
        Can animals and plants adapt to global warming?
        Re #39 Mizimi, Since pretty much all of science and most economists and corporate and government leaders and so on consider that if will be increasingly more damaging to our economies to ignore the problem of massive man-made enhancement of the Earth's greenhouse effect than it will be to mitigate the effects through greenhouse gas emission reduction programmes, it's not really a choice of unknowns. We know things are going to become increasingly problematic in a warming world (enhanced drought, increased adverse weather effects, rising sea levels threatening massive coastal populations and industrial infrastructure, species extinctions, water restrictions and resulting conflicts and so on). The point is that global warming is already having adverse effects on many millions of people. So far they're largely the "readily ignorable" in Africa and other low latitude regions where global warming is already enhancing water shortages and agricultural disruption. Addressing this problem by taking mature and rational measures to limit greenhouse gas production, especially by developing and implementing alternative energy sources will benefit everyone. So your notion of choice based on an ill-informed presumption of uncertainty just doesn't accord with the informed view. And the idea of "deciding which species should be preserved" is also a fallacious one. We recognise that we are impoverished both economically and as human beings as the natural world degrades around us. The aim is to preserve the biosphere to a maximum extent (which is very widely recognised). Witness the efforts to enhance no-fishing zones to preserve ocean biodiversity (and it's obvious economic benefits) and to increase the numer and extent of wildlife preserves. These efforts will only be successful on a large scale if efforts are also made (as they are) in developing the sustainable energy sources that constitute the only possible future for mankind. So self-preservation also informs us to act rationally to limit our greenhouse gas emissions.
130997. chris at 06:36 AM on 5 October 2008
        Can animals and plants adapt to global warming?
        Re #40 HealthySkeptic Yes, as you indicate, the Earth's global temperature is intimately linked with the atmospheric greenhouse gas concentration. As you intimate, that's an inescapable conclusion of an abundant and growing body of science. However your finishing pondering is rather misplaced. The present massive outpouring of greenhouse gases from our emissions is a concern for the coming decades and few centuries. I think we can leave our descendants of 50,000 years down the road to look after themselves! After all Homo sapiens has only roamed the earth for around 200,000 years, mankind was only just dabbling in the earliest forms of agriculture, animal husbandry and early "permanent" settlements around 20,000 years ago (during the last glacial period, in fact) and recorded civilisation only goes back a few thousand years. If we look after ourselves and the rest of the biosphere over the next decades and few hundreds of years, there's a pretty good chance that our 50,000-year hence descendants may be in good shape to deal with the next major Milankovitch cycle.... ...or maybe not...who can say what might accrue in the vast period of "meantime" between now and then!
130998. chris at 06:23 AM on 5 October 2008
        Can animals and plants adapt to global warming?
        Quietman, you've made three errors in your short sequential posts. Re #41: You've mixed up "evolution" with "extinction". Evolution does favour species with appropriate adaptations. However extinction events are rather less discriminate in their effects on species survival. Many (perhaps all) of the cataclysmic extinctions in the past are well-associated with marked global-scale warming at a rate that overpowers the adaptability of species. This is what the biosphere faces now, just as in the past. Re #42: Of course the greenhouse isn't a hypothesis. It's been known since the mid 19th century (since the time of Tyndall and others) that the black body temperature of the Earth is around 30 oC colder than our extant temperature. Without our greenhouse effect there would be no liquid water on the surface of the Earth. That's not a hypothesis. That's a fact. Let's not pretend that we don't know what we do know. Atmospheric CO2 is a greenhouse gas and contributes to the Earth's warmth. If the atmospheric concentration of CO2 rises, so does the Earth's equilibrium temperature, all else being equal. Re #43: You're mistaken. Perhaps you haven't read the papaers or are unfamiliar with the science. All of the papers I've cited report independent measures of paleotemperature and paleoCO2. They make no assumptions whatsoever about "the sensitivity" and have nothing to do with "the IPCC". There's no point in saying stuff that is simply not true Quietman.
130999. chris at 05:39 AM on 5 October 2008
        Does Urban Heat Island effect add to the global warming trend?
        Re #5 Quietman, I expect that it doesn't "show up" because the NASA data is obtained from measurements rather than from personal anecdotes! In any case Southern California hasn't warmed that much in living memory. Less than 1 oC overall and if one focuses on the winter (when your pipes would have frozen) there hasn't been significant warming in Southern CA at all since the 1930's, for example. All of this does show up in the data from NASA. You can accss this yourself very interactively. Try: http://data.giss.nasa.gov/gistemp/maps/ where you can create your own spatially-resolved maps defining the measured temperature change over any specified period. You can analyze this by month, by season or annually. You'll see that Southern CA has been an oasis of cool during the winter months....
131000. Patrick 027 at 05:31 AM on 5 October 2008
        Volcanoes emit more CO2 than humans
        "I have read your argument a dozen times" Wow! Thanks for the effort! I suppose it would have been helpful if I had written a summary. TIDES ON EARTH: Outside of oceanic effects (and maybe a few glaciers at sea level), too weak to expect a significant effect on: 1. mantle convection and the overall rate of plate motions (which can't change fast anyway). 2. earthquakes and volcanic activity - at least in the longer term trends (as opposed to variations over cycles of 1/2 day, day, 1/2 month, month, etc.), if not even in those shorter term cycles. 3. the Geodynamo and outer core motion 4. the atmosphere, ionosphere (including E-region dynamo, in the base of the thermosphere), and magnetosphere (except in the magnetotail at those times of the month when the moon actually would get near or intersect it, although even then, on further reading it seems the magnetic forces on charged particles with the kinds of energies involved would overwhelm gravitational effects - and also, outside of the monthly and ~18-year cycles, what effect could that have, and even then, what would the significance of that be to Earth?) And where the tides have a significant effect, how would that effect relate to climate changes over a ~100 year period (as opposed to a ~ 20 year period or especially a 1/2-month (spring to neap to spring again)period)? TIDES CENTERED ON SUN (due to planets): far too weak to expect significant effect on: 1. solar convection or solar dynamo, and hence, 11-year sunspot cycle, other related phenomena including TSI variations 2. solar wind and interplanetary magnetic field (except, for effects on Earth, perhaps when Earth get's near the wake of Venus or Mercury, - **although most of that effect wouldn't actually be from the gravity of Mercury or Venus - and what effect could it be?) - this is especially considering the case considering the much much larger variations that do occur in solar wind density and velocity... TIDES ON SUN VS 'SOLAR JERK', FAIRBRIDGE CYCLE: I had thought that if the there was a correlation of solar TSI or solar wind and magnetic field to the solar jerk, it would be because they would both be correlated to the tides on the sun, which might have an effect on solar TSI, wind, and magnetic field (though an insigificant effect for our purposes, from my reasoning). The solar jerk is just the changing free-fall of the sun so it is hard to see how that would affect solar activity (as I explained elsewhere). However, it is interesting that while both such tides and 'jerk' depend greatly on Jupiter, the jerk depends also on the other gas giants due to their mass and distance, and the contribution of the 4 inner planets is tiny in comparison, whereas the three most important planets after Jupiter for the tides on the Sun are Venus, Earth, and Mercury. ---- ... Further reading on magnetosphere, solar wind...: (PS I have only browsed many of the following, with one noted exception): http://en.wikipedia.org/wiki/Magnetosphere http://en.wikipedia.org/wiki/Magnetosphere_particle_motion http://en.wikipedia.org/wiki/Guiding_center but of course one must be careful with wikipedia (their article on tides suggests the human menstrual period could be an evolutionary artifact of distant sea-dwelling ancestors' adaptations to tidal cycles, when in fact this doesn't seem likely at all, particularly considering the menstrual cycle periods of our closer relatives - it is just a coincidence) - on the other hand, it is possible to figure out whether or not the math and physics work out as such. But also: http://www-ssc.igpp.ucla.edu/ssc/tutorial/magnetosphere.html (which I have read completely) http://farside.ph.utexas.edu/teaching/plasma/lectures/lectures.html http://www-istp.gsfc.nasa.gov/Education/Intro.html ----- On a possible connection of oceanic tides to climate: http://www.pnas.org/content/94/16/8321.full I think there was a related article to the above, which focussed on a correlation of shorter term variability to oceanic tidal forcing. I haven't read through these closely enough to see just how much variability in tidal forcing there is relative to the tidal forcing itself - the largest I do expect is the spring-neap variation, but there are other variations... but I expect they are smaller especially in the long term variations - so I am arguing that oceanic tidal variations are significant in climate variations on the multidecadal to century to millenial or beyond timescale, but it is interesting to consider. I don't think the authors would or could argue that this could account for the warming of the last few decades...

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