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All IPCC definitions taken from Climate Change 2007: The Physical Science Basis. Working Group I Contribution to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change, Annex I, Glossary, pp. 941-954. Cambridge University Press.

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Comments 71901 to 71950:

  1. Human CO2 is a tiny % of CO2 emissions
    Bugai #201, Also in the Joos et al. paper you cited, they've set the air-sea exchange to zero for figure 3 (see appendix A1). The curves in their figure shows how quickly tracers move from the surface to deep ocean, and that is certainly not the relaxation time we're discussing.
  2. Clouds provide negative feedback
    174, lancelot,
    So while RW1 has not proposed a mechanism, others appear to have.
    I'm afraid I don't see that. Can you be more specific? The question at hand is: "Given warming that results from anthropogenic CO2, what will be the resulting cloud feedback?" While the work you discuss is interesting, it does not in any way affect the topic at hand -- which is the direction and degree of feedback from clouds in response to warming. That cloud formation is impacted by many factors is obvious. That temperatures are impacted by unexpected but measurable factors such as cosmic rays, through cloud formation, is what is under debate in current science (and on other threads here at SkS) but at the current time is not in any way supported by the evidence available. But in any event, it is not relevant to this thread, which discusses cloud feedbacks, not clouds as a primary forcing.
  3. Sea levels will continue to rise for 500 years
    @Agnostic #57: The issue you have raised is directly addressed in "The Next 500 Years of Sea Level Rise" by Michael Lemonick posted on Climate Central on Oct 19. Lemonick had posed that very same question to Aslak Grinsted.
  4. Clouds provide negative feedback
    lancelot#174: "Svensmark, Shaviv, J Kirkby et al all suggest a mechanism" Those gentlemen are all part of the 'it's cosmic rays' camp. There are a number of threads addressing their data here at SkS (search: cosmic rays), as well as this excellent RealClimate piece exploding their suggested mechanism.
  5. The human fingerprint in the daily cycle
    An uncharacteristically perceptive comment by one of JCurry's 'denizens' in the midst of their agonized debate on the BEST temperature work: it is alleged that due to increased green house gases in the atmosphere, heat is trapped that cannot escape from earth. So if an increase in green house gases is to blame for the warming, it should be minimum temperatures (that occur during the night) that must show the increase (of modern warming). In that case, the observed trend should be that minimum temperatures should be rising faster than maxima and mean temperatures. That is what would prove a causal link. -- emphasis added This fellow goes on to admit a cherrypick ("my carefully chosen sample of 15 weather stations") of some recent data to demonstrate that in a few locales, DTR is not decreasing. But as we've seen here and here, there is ample evidence of DTR decrease. Other references for DTR decrease include Zhou et al 2005: Such spatial dependence of Tmin and DTR trends on the climatological precipitation possibly reflects large-scale effects of increased global greenhouse gases and aerosols (and associated changes in cloudiness, soil moisture, and water vapor) during the later half of the twentieth century. Zheng et al 2010: ... for the later period of 1951–90, the trend in maximum temperature reduces to an insignificant value, while the trend in minimum temperature remains high, resulting in a significant downward trend in diurnal range of 0.10°C/decade. From Martinez et al 2009, despite variations due to seasonal effects, an average annual decreasing trend of DTR is found, particularly relevant in autumn (−0.9 °C/decade).
  6. Clouds provide negative feedback
    Interesting thread. Is it still active? On mechanisms: Svensmark, Shaviv, J Kirkby et al all suggest a mechanism for cloud nucleation (and thus possibly formation) independent of temperature. I was surprised not to see this mentioned. Other possible mechanisms have been proposed, such as micro organisms prompting nucleation. http://www.wired.com/wiredscience/2011/05/microbes-make-rain/ So while RW1 has not proposed a mechanism, others appear to have. No hard evidence for those mechanisms, but they should perhaps be considered when assessing the evidence for other mechanisms such as co2 forcing.
    Response:

    [DB] "Interesting thread. Is it still active?"

    All threads here at SkS (all 4,000+) are active.  Many are temporarily dormant but any are free to be reawakened at any time.  Regular participants here follow the Recent Comments thread, so they will see any new comment made regardless of the thread it is posted on.

  7. Abraham reply to Monckton
    Scoop! "Lord Monckton" actually always has been Sasha Baron Cohen in unbelievably convincing character!
  8. Continued Lower Atmosphere Warming
    The tail end of new the BEST temperature reconstruction: is not very friendly to the 'warming stopped in ____' crowd, nor is it supportive of Dr. Pielke's '2002 change in trend is significant' interpretation. Put in the perspective and detail of the BEST graphic, short term downtrends are a regular feature of the temperature record, as there are too many of these 'blips' to count. Despite the jagged appearance, the overall trend is up: since ~1970, ~1 degree in 40 years.
  9. Sea levels will continue to rise for 500 years
    Hyperactive Hydrologist shares my concerns about the WAIS being more of a threat to SLR than does the GIS. Once the restraining influence of the PIG & Thwaites linchpin are removed the risk of ice sheet dynamic decomposition of the WAIS escalate. Melt rates are a non-issue compared to that. I've been planning on writing a post on this for some time; perhaps the time has come to put aside malaise and laziness and actually do it.
  10. The BEST Kind of Skepticism
    Bern @29, Oil & coal will run out in ~300y at current rat, so your will is actually pessimistic. Had that happen (300y of BAU) we would certainly head for PETM scenario (56mya) when arctic ocean temp was 74F... Hopefully it won't come to that. Back to our times: denialist are disturbed and hopefully their influence dies much sooner than the fosils are burned. If it happens in decade or two, it won't be bad, perhaps not too late.
  11. Sea levels will continue to rise for 500 years
    Hyperactive Hydrologist - yup, that seems to be the conclusion of a couple of recent papers - the West Antarctic Ice Sheet may have been the main contributor to sea level rise in recent (ish) warm periods. See SkS post: Rising Oceans - Too Late to Turn the Tide? and The Role of Ocean Thermal Expansion in Last Interglacial Sea Level Rise - McKay (2011) the study referenced.
  12. Hyperactive Hydrologist at 20:02 PM on 22 October 2011
    Sea levels will continue to rise for 500 years
    Glenn, I'm not disputing rapid ice loss and subsequent rise in sea level. I'm saying perhaps Greenland is more stable and resilient to complete collapse compared with the Western Antarctica (WAIS) based on topography. In-situ melting of a large ice sheet will be much slower than an ice sheet losing mass from glacial carving and in-situ melting. WAIS has the potential to suffer from a mechanism of sea water intrusion and consequently an increase in basal lubrication. For me the real danger of rapid or even catastrophic sea level rise comes from the WAIS. The key is how much of an impact will 2-4oC of warming have on Antarctica.
  13. OA not OK part 20: SUMMARY 2/2
    Don't look at me. I have no intention of rolling in the muck with the crowd at Watts. I leave it to those of a pachycephalsauriaic disposition to deal with. Bernard: Perhaps your pedantry is up to the task? I still don't follow your concern. A definition of 'neutral' is not relevant to a definition of acidification. We thought we were careful in the first post to remind readers that acidification is an absolute increase in [H3O+] and not a relative change with respect to some 'neutral' point. (Yes, yes, actually activity not concentration but we also explained that we would avoid activities to not totally confuse readers).
  14. Sea levels will continue to rise for 500 years
    Hyperactive Hydrologist. Catastrophic collapse is unlikely. On what time scale? If a couple of 1000 years of temps maybe 0.5 C warmer than now removed 1/2 or more of the GIS, what will the rate of loss be with temps 2-4 C warmer than now? How much of decline is movement towards the coast, how much is melting in-situ? Today? What will this balance be in 50 years?, 100? 200?
  15. Berkeley Earth Surface Temperature Study: “The effect of urban heating on the global trends is nearly negligible”
    @John Russell I'd say you're right on that. And when we have all forgotten all the previous debunkings they will return once again to the old chestnuts. I heard two the other day "peer reviewed by who?" and "but the Earth is only 6000 years old, there can't be a carbon cycle." Fortunately the later doesn't come up too often.
  16. Ocean Heat Poised To Come Back And Haunt Us?
    David Lewis -"I wonder why you report on the science as if one of the organizations did not exist" I wonder why you would write such a thing when you commented on another recent(ish) post which attributed the slowdown to pollution aerosols from Asia? We'll just have to wait and see how this plays out. As I mentioned in the other post, some papers on the effect of Asian pollution on global dimming are awaiting publication. In the meantime, I see little point in you repeating the same things over and over again.
  17. The BEST Kind of Skepticism
    Bert: those who are actually sceptical as to whether the Earth is warming will probably be convinced by the BEST study. Those in denial will not be. But many of those who were sceptical about the warming will shift their scepticism to the causes of warming. Maybe the BEST team can tackle that next? ;-) Hey, maybe in a decade of two, when they've reproduced & confirmed the last few decades of climate science as a whole, we might start to see some real public acceptance? Naaaaaaah! That'll only happen when the oil & coal actually runs out, and the denialist organisations run out of funding.
  18. Climate sensitivity is low
    Thanks Sphaerica, your response was just what the doctor ordered! xox
  19. The BEST Kind of Skepticism
    Mal Adapted, I'm tempted to drive up to Santa Fe to catch the proceedings. The Tuesday morning Observations session could be interesting: Muller gives his presentation from 10:55-11:15 followed by Rohde from 11:15-11:35, followed by a certain F. Singer presenting "Is the reported global surface warming of 1979 to 1997 real?" I'm not sure how these conferences are, but the ones I've been to something like that would spark some interesting, uh, discussions.
  20. Philippe Chantreau at 14:09 PM on 22 October 2011
    The BEST Kind of Skepticism
    Bert, as their actions indicate, the term scientist would not apply by any stretch to Easterbrook, Monckton or Goddard.
  21. Bert from Eltham at 12:58 PM on 22 October 2011
    The BEST Kind of Skepticism
    Apart from carefully collected and drafted evidence and solid conclusions, what else can you do to convince sceptics? I am totally at a loss as to the blindness of seemingly rational scientists. Bert
  22. Berkeley Earth Surface Temperature Study: “The effect of urban heating on the global trends is nearly negligible”
    Improved energy use? Removal of power generators from the cities?
  23. Human CO2 is a tiny % of CO2 emissions
    bugai#195: "we destroy the CO2 sink by pollution of the oceans" We pollute the oceans, sufficient to 'destroy' the CO2 sink, yet we do not produce the CO2 that goes into the atmosphere? BTW, we also influence atmospheric ozone and produce CO, N2O, NO, among other gases, but not CO2? Seems like an inconsistent position to me.
  24. How Increasing Carbon Dioxide Heats The Ocean
    Rob - I was imprecise in my language. The warming of the skin layer increases the gradient between the cooler air and the top of the warmer skin layer - increasing the heat transfer from the water to the air.
  25. Human CO2 is a tiny % of CO2 emissions
    Bugai, Your own model suggests that T cannot possibly be 5-10 years. Say we linearize about the pre-industrial level and assume that's the equilibrium. The resulting DE will be dC/dt=E_a-C/T Notice that E_n disappears due to linearization. C here is the CO2 above the preindustrial level of 280ppm. Currently we have dC/dt=14 Gt/yr, E_a=29 Gt/yr gives C/T=15 Gt/yr Now the CO2 level has increased by about 100ppm, with is about 770Gt. This yields T of 51 years.
  26. The BEST Kind of Skepticism
    Hopefully there will be a Skeptical Science special on the Easterbrook debacle textbook soon!
  27. The BEST Kind of Skepticism
    Muller and Rohde will present their results on November 1, at the Third Santa Fe Conference on Global and Regional Climate Change. Also on the conference program are R. Lindzen, D. Easterbrook, C. Monckton, F. Singer, J. Curry, and other well-known denierskeptics. I wonder how the BEST results will be received?
  28. Human CO2 is a tiny % of CO2 emissions
    bugai, your position appears to be self contradictory. Let's assume for the moment that your arguments of '5 year relaxation time' and 'CO2 accumulation due to pollution decreasing natural sinks' are correct... I don't see how that changes the conclusion that the increase in atmospheric CO2 levels is entirely due to human emissions. You concede that natural emissions are less than natural sinks... ergo natural emissions CANNOT be causing the rise in atmospheric CO2 levels. You also agree that humans are emitting enough to increase atmospheric levels by about 4ppm per year, but the actual rate of increase is only about 2ppm. You argue that this accumulation is due to reduced natural sinks... but even if that were true, it changes nothing. Nature is taking out less than it would if not for pollution. Ok... but the accumulating excess is STILL entirely derived from human emissions since even these 'reduced' natural sinks are greater than the natural emissions.
  29. Dikran Marsupial at 09:25 AM on 22 October 2011
    Human CO2 is a tiny % of CO2 emissions
    KR, IIRC the 74 year figure is the e-folding time, i.e. the time taken for the concentration to fall to 1/e of its initial value.
  30. Human CO2 is a tiny % of CO2 emissions
    (-Snip-) Their CO2 models strongly depend on the ocean surface temperature. Taking a (-snip-) feedback of temperature rise due to extra CO2, you can (-snip-) any "relaxation time", even millions of years. I find the Bern CO2 model much more transparent: http://onlinelibrary.wiley.com/doi/10.1034/j.1600-0889.1996.t01-2-00006.x/pdf The only drawback of that model is that it discards the dynamics of biologic removal of CO2 from the ocean. It implicitely assume that it is "constant". Look at the pulse response in Fig.3 and you see that the relaxation time is 5 years or even less. As it has been numerously measured in 50-ies and 60-ies of the last century. And yes, I claim it is the problems with a too weak sink of CO2, not with extra emission. That is why CO2 is rising. Even if the oceans are a net CO2 sink now.
    Response:

    [DB] Allegations of fraud and impropriety on the part of the IPCC snipped.  It is time to familiarize yourself with the Comments Policy here.  Future comments containing such violations will be simply deleted.

    Thank you in advance for your understanding and your compliance in this matter.

  31. Human CO2 is a tiny % of CO2 emissions
    From previous post: half-life of 34.66 years. Half life = ln(2)/rate = ln(2)/0.02% = ~34.66
  32. Human CO2 is a tiny % of CO2 emissions
    Dikran - What level of decay are you looking at for adjustment time? 20%? Reason why I'm asking: Given 2ppm/year decay scaled to imbalance, and an imbalance of ~100ppm, I get a half-life of 34 years (38 years for 2ppm and 110ppm imbalance), decaying to 20% at ~79 years, assuming a single exponential decay model. Granted, that's wrong, as only the initial decay is primarily the ocean pH adjustment, and longer term exponentials for shell sequestration and deposition are going on at the same time... so the actual decay will take 100's to thousands of years. But I've found showing the fastest possible exponential decay to be useful in these discussions.
  33. Ocean Heat Poised To Come Back And Haunt Us?
    It appears to me that GISS and NCAR have very different ideas on the issue discussed in this post. NCAR appears to take the output of many models as to what the planetary energy imbalance is, i.e. they calculate it is about 1 W/m2, they find that this number appears to confirm estimates of what satellite observation finds is happening at the Top of the Atmosphere, they compare to observations where heat can be measured in the planetary system, things don't add up, so they look for "missing energy". NCAR models show the energy is going into the ocean, so NCAR is looking for it there. GISS, i.e. Hansen, has been saying for years that the figure for the planetary energy imbalance is lower, somewhere between .5 and .75 W/m2. His recent "Earth's Energy Imbalance" paper cites Von Schuckmann et al Argo data analysis. Rather than looking for missing energy, Hansen has decided there is a problem with the models, a position he has held for some years. The fact that most models, including his at GISS, calculate the current planetary energy imbalance as 1 W/m2 means to him that the models are incorrect. There isn't any missing energy. "Most climate models mix heat too efficiently into the deep ocean". As I understand things, you don't get more diametrically opposed than NCAR and GISS are on this. Now if senior people working at these top flight institutions, NCAR and GISS, disagree this fundamentally, I wonder why you report on the science as if one of the organizations did not exist. I note that Gavin Schmidt at RealClimate says, on what looks like this issue is "I don't see any contradiction." (See end of this comment at RealClimate) NCAR appears to believe that the Top of Atmosphere observations, supported by the output of most climate models, can be taken as more likely to be valid on what the planetary energy imbalance is, than current ocean data. For instance, Trenberth says this, around 1:03:30 in this video: "the suggestion is that a lot of the ocean is not being adequately monitored at the current time and that this is not a problem with the measurements at the Top of the Atmosphere, but rather, it is a problem with how we can account for what is going on within the ocean." Whereas Hansen blasts the Top of Atmosphere satellite observations. In his recent paper he has a section discussing present abilities and future prospects for accurately measuring the energy imbalance at TOA. The present generation of satellites, CERES, he says "finds a measured 5 year mean imbalance of 6.5 W/m2", which he says was simply corrected with arbitrary "calibration factors" "to reduce the imbalance to the imbalance suggested by climate models" because the actual uncorrected result was "implausible". As for any future satellite operating at the Lagrange L1 point as some have suggested, he says the "notion that a single satellite at this point could measure Earth's energy imbalance... is... preposterous". All seem to agree that there is great potential in data from Argo. Perhaps the resolution on this point will come as confidence arrives about analyses of Argo data.
  34. The BEST Kind of Skepticism
    Well, to start off with, Monckton recycles his debunked Congressional testimony, bombards the reader with maths (which are never seen in any other part of the textbook), and cites Rachel Pinker yet again. A chapter written by Goddard is completely devoted to showing that 2010 was not the hottest year on record and is laden with digs at James Hansen. Every page has at least one illustration, often generated by Wood for Trees, and often taking up over half the page. Another Goddard chapter, "Arctic Sea Ice," is much the same way. Throughout the book there are oodles of citations from Climate Audit, WUWT, World Climate Report, and SPPI. Furthermore, several chapters are completely missing their bibliographies. This is the kind of stuff that gets you put on academic probation as an undergraduate student.
  35. Dikran Marsupial at 08:35 AM on 22 October 2011
    Human CO2 is a tiny % of CO2 emissions
    bugai So you think that the natural environment has caused the rise in atmospheric CO2 even though it has taken more carbon dioxide out of the atmosphere every year than it has put in? You are essentially saying that the natural environment has caused the rise in atmospheric CO2 by taking CO2 out of the atmosphere. Do you realise how absurd that sounds? You assume "Not far from equilibrium we can write for the natural sink: U_n = C/T" however, the carbon cycle is no where near equilibrium, we are currently 100ppmv over the pre-industrial equilibrium that had held for several thousand years at least. You are basing your argument yet again on the asumption that the relaxation time is 5 years. This is incorrect, the residence time is 5 years, the relaxation time (as you call it) is much longer. I have done the differential equations, and they give a figure of 74 years.
  36. The BEST Kind of Skepticism
    A true sceptic would have recognized that the NOAA/GISS data are not really comparable to the HadCRUT. It's just a question of coverage. HadCRUT has only about 80% coverage while NOAA and GISS cover almost all of the surface (although they do not really have the data, but they do a very good job with their approximations). And, if compared with satellite data of a nearly equal coverage, we have quite fine correlations: RSSMSU vs. HadCRUT for nearly 80% and UAH vs. GISS for 100% coverage. If someone means that a record is "biased", the one forgets the fact of different coverages. The BEST study supports the data of 100% coverage, but it cannot approve the HadCRUT record to be biased, because they show their coverage values in the record. Greetings from Germany.
  37. Human CO2 is a tiny % of CO2 emissions
    bugai - "If we switch out antropogenic CO2 source abruptly, the CO2 levels would be declining by >2ppm/year just for the relaxation time: the 5 years." And now we're on step 2, your conflation of molecular residence time with atmospheric concentration adjustment time. I'll now refer you (again) to the IPCC 7.3.4.2 Carbon Cycle Feedbacks to Changes in Atmospheric Carbon Dioxide, which actually examines these rates for various sequestration pathways. Short term adjustments to CO2 imbalance have about a 37-40 year half-life, with a very long tail once pH buffering tapers off and biological sequestration and geologic impoundment take over. [ Source ] See also the IPCC glossary for "Lifetime", as Dikran mentions, here, on page 948. Again - residence time for individual molecules is quite short. But in the presence of bi-directional exchanges, it is not the concentration adjustment rate. That's a common mistake - but it's a mistake.
  38. Dikran Marsupial at 08:21 AM on 22 October 2011
    Human CO2 is a tiny % of CO2 emissions
    bugai wrote "If we switch out antropogenic CO2 source abruptly, the CO2 levels would be declining by >2ppm/year just for the relaxation time: the 5 years." It has been pointed out to you repeatedly that the relaxation time is not five years, the residence time is five years. They are not the same thing. Perhaps you would like to look up lieftime in the glossary of the IPCC WG1 report and tell us what it says there.
  39. Human CO2 is a tiny % of CO2 emissions
    @Dikran Marsupial: This is a point we disagree. >>>> (i) demonstrate that step 5 is incorrect The formula is perfectly correct. >>>> (ii) demonstrate that the natural environment can be the cause of the observed rise even though it is a net carbon sink Yes, it is. I know, you do not like differential equations, but we do need them to understand the problem. We write: dC/dt = E_a + E_n - U_n Certainly, U_n > E_a, and still it is the nature that is responsible for the CO2 rise. Not far from equilibrium we can write for the natural sink: U_n = C/T where T is the relaxation time, in our case somewhere 5-10 years. It is not constant, but depends on the state of the sink (ocean pollution). So, we write T(t). If we monitor CO2 on time scales larger than the relaxation time, dC/dt << C/T, the quasistatic (but time-dependent!) CO2 level is C(t) = (E_n(t) + E_a(t))/T(t) It is the change in T(t) that drives the CO2-level in the atmosphere, not E_a. here Sn is the natural source, Sa (iii) agree that the observed rise is not a natural phenomenon. 1. >>>> Current anthropogenic CO2 contribution: ~29GT/year. Current yearly atmospheric CO2 accumulation: 2ppm/yr or ~14GT/year. delta CO2 (D) = Sources (S) - Sinks (K) D = (anthro S + natural S) - (anthro K + natural K) D = (aS + nS) - (aK + nK) = 14GT/yr [ for convenience ] Anthropogenic sinks (aK) are essentially zero. If we subtract anthropogenic sources (aS) from both sides of the equation: -15GT/year = nS - nK Natural sinks > Natural sources by ~15GT/year at present. <<<<<<< Correct. I agree with these numbers completely. 2. >>>>>> So without our contribution to atmospheric CO2, CO2 levels would be declining by >2ppm/year right now. Hence we are indeed responsible for increasing atmospheric CO2. Early in the industrial revolution, anthropogenic contributions were much lower, but the imbalance in CO2 was much smaller, hence the natural sink of CO2 driven by that imbalance was smaller as well. See the history of emissions and CO2 levels for that relationship. Nature is acting as a net sink - anthropogenic contributions are responsible for rising CO2 levels. That's "1st class school math" - any disagreements? <<<<<<< Disagree. If we switch out antropogenic CO2 source abruptly, the CO2 levels would be declining by >2ppm/year just for the relaxation time: the 5 years. Then CO2 level change due to antropogenic source will relax completely and the CO2 level will be moving - in whatever direction! - by the disbalance of the natural sources and sinks. Because we destroy the CO2 sink by pollution of the oceans, after 5 years have passed, the CO2 level will continue to rise at the same rate as it does now.
  40. Sea levels will continue to rise for 500 years
    John - All very true but why go back to step 1 when we are already well down the road?
  41. Human CO2 is a tiny % of CO2 emissions
    @KR: 1. >>>> Current anthropogenic CO2 contribution: ~29GT/year. Current yearly atmospheric CO2 accumulation: 2ppm/yr or ~14GT/year. delta CO2 (D) = Sources (S) - Sinks (K) D = (anthro S + natural S) - (anthro K + natural K) D = (aS + nS) - (aK + nK) = 14GT/yr [ for convenience ] Anthropogenic sinks (aK) are essentially zero. If we subtract anthropogenic sources (aS) from both sides of the equation: -15GT/year = nS - nK Natural sinks > Natural sources by ~15GT/year at present. <<<<<<< Correct. I agree with these numbers completely. 2. >>>>>> So without our contribution to atmospheric CO2, CO2 levels would be declining by >2ppm/year right now. Hence we are indeed responsible for increasing atmospheric CO2. Early in the industrial revolution, anthropogenic contributions were much lower, but the imbalance in CO2 was much smaller, hence the natural sink of CO2 driven by that imbalance was smaller as well. See the history of emissions and CO2 levels for that relationship. Nature is acting as a net sink - anthropogenic contributions are responsible for rising CO2 levels. That's "1st class school math" - any disagreements? <<<<<<< Disagree. If we switch out antropogenic CO2 source abruptly, the CO2 levels would be declining by >2ppm/year just for the relaxation time: the 5 years. Then CO2 level change due to antropogenic source will relax completely and the CO2 level will be moving - in whatever direction! - by the disbalance of the natural sources and sinks. Because we destroy the CO2 sink by pollution of the oceans, after 5 years have passed, the CO2 level will continue to rise at the same rate as it does now.
  42. How Increasing Carbon Dioxide Heats The Ocean
    guinganbresil - ""A warming of the skin layer just increases this gradient, increasing the heat transfer - it is essentially a wash." No, warming decreases the gradient. Warming from the surface (longwave radiation) means the temperature difference between the bottom of the layer and the (now warmed) top is smaller - therefore the gradient decreases and slows the heat transfer process (ocean to atmosphere). The point to remember is that this greenhouse gas-warmed cool skin layer is global in scale - all heat transferred from the ocean has to go through this layer. Anyway I'll get around to giving this post a re-write, and include some diagrams.
  43. Human CO2 is a tiny % of CO2 emissions
    bugai#181: "You cannot see "diurnal" osciillations there, but certainly the seasonal ones." Perhaps you should study the literature on CO2 monitoring a bit more, rather than make quite so many assumptions. Chmura 2005 et al is a good starter, showing that an industrial city is a CO2 source: The CO2 mixing ratios measured in the urban atmosphere revealed quasi-permanent excess concentration of this gas when compared with near-by background atmosphere. The annual mean CO2 concentration recorded in Krakow in 2004 was almost 10% higher than that recorded at high-altitude mountain site (Kasprowy Wierch). Such effect is occuring probably in all urban centers. There is indeed a diurnal signal: In the urban environment, the lowest CO2 mixing ratios are recorded generally during mid-day, when the convective activity of the lower atmosphere and resulting vertical mixing is at its maximum. In contrast, at the mountain site high CO2 mixing ratios are generally recorded during mid-day and early afternoon. This stems from sun-driven convection within the planetary bounday layer over Kasprowy Wierch “sucking” the CO2-laden air from the valleys towards the top of the mountain. In addition, there is an isotopic signature to anthropogenic emissions: Seasonal fluctuations of delta13C visible at both discussed sites are shifted in phase. The Krakow record reveals lowest delta13C values during winter season, when local CO2 emissions due to burning of fossil fuels in the city (heating plus car traffic) are most intense. So the record of CO2 emissions appearing in the atmosphere is unmistakeable. You seem to rest your case on 'it can't be us.' Can you provide anything more substantial than that?
  44. Dikran Marsupial at 07:52 AM on 22 October 2011
    Human CO2 is a tiny % of CO2 emissions
    KR sure, as it happens we were almost there: step #1 The carbon cycle obeys conservtion of mass, so the annual rise in atmospheric CO2 is equal to total emissions minus total uptake step #2 We can write this as ΔC = E_a + E_n - U_n where ΔC is the annual increase in CO2 E_a is annual anthropogenic emissions E_n is annual emissions from natural sources U_n is annual uptake by natural sinks all of these quantities are of course positive. Step #3 rearranging ΔC - E_a = E_n - U_n Step #4 if the left hand side is negative, then the right hand side is negative, so if E_a > ΔC then we know that U_n > E_n also I'm assuming that bugai agrees with this as (i) it is elementary mathematics, and (ii) he had plenty of opportunity to say it was wrong but didn't. Step #5 - look at the data. The blue line is E_a, the red line is ΔC, and the green line is E_n - U_n estimated by ΔC - E_a. The data are all freely available from the Carbon Dioxide Information and Analysis Center (here, here and here). This clearly shows that E_a > ΔC and so we know that U_n > E_n. In other words we know that environmental uptake has exceeded environmental emissions every year for the last fifty years at least, and hence has been opposing, rather than causing the observed atmospheric increases. Bugai only had one step left to go, pity he preferred to be obstinate. So bugai, you have three options: (i) demonstrate that step 5 is incorrect (ii) demonstrate that the natural environment can be the cause of the observed rise even though it is a net carbon sink (iii) agree that the observed rise is not a natural phenomenon.
  45. Human CO2 is a tiny % of CO2 emissions
    bugai - One thing at a time, for the moment. Current anthropogenic CO2 contribution: ~29GT/year. Current yearly atmospheric CO2 accumulation: 2ppm/yr or ~14GT/year. delta CO2 (D) = Sources (S) - Sinks (K) D = (anthro S + natural S) - (anthro K + natural K) D = (aS + nS) - (aK + nK) = 14GT/yr [ for convenience ] Anthropogenic sinks (aK) are essentially zero. If we subtract anthropogenic sources (aS) from both sides of the equation: -15GT/year = nS - nK Natural sinks > Natural sources by ~15GT/year at present. So without our contribution to atmospheric CO2, CO2 levels would be declining by >2ppm/year right now. Hence we are indeed responsible for increasing atmospheric CO2. Early in the industrial revolution, anthropogenic contributions were much lower, but the imbalance in CO2 was much smaller, hence the natural sink of CO2 driven by that imbalance was smaller as well. See the history of emissions and CO2 levels for that relationship. Nature is acting as a net sink - anthropogenic contributions are responsible for rising CO2 levels. That's "1st class school math" - any disagreements?
  46. Arctic Ice Volume is diminishing even more rapidly than Area
    Correction since the 1950s. Apologies !
  47. Human CO2 is a tiny % of CO2 emissions
    @KR: You say "Incorrect - a 5% input sustained over centuries..." Certainly incorrect. Antropogenic CO2 source: In year 2005: 30 billion tons. In year 1945: 5 billion tons. In year 1850: 0.1 billion tons. "Centuries" of 5% emission? Assuming a constant natural CO2 source, the antropogenic CO2-source was just miniscule 0.9% at 1945. And - (-Snip-) - the striking 0.01% antropogenic emissions there leading to the end of LIA! 2. - "These (plankton die-off, ocean warming) are the two main reasons for CO2 rise, not the tiny emission by the fuel combustion" Sorry, unsupportable statement contradicted by all the science. We know the rates for those, and for anthropogenic emissions, and the math just doesn't support this claim. ///////// You know the exact rates? Put them forward.
    Response:

    [DB] Inappropriate tone snipped.

  48. Ocean Heat Poised To Come Back And Haunt Us?
    Trenberth (1:10:50 or so of this video) points out that the heat the NCAR model shows going into the ocean is "mainly in the Pacific" "in the subtropics, or up to about 40 degrees latitude". "And so, if the model is anything like right, it suggests where we should start looking harder at the observations". When asked about what "the mechanism" was that could move this heat into the deeper parts of the ocean enough to flatline the average global surface temperature graph for a decade he mentioned a number of possibilities: "there are subtropical overturning circulations in the Pacific that clearly play a substantial role in moving heat around although the main thought is they have been involved in the top 400m or something like that. And so there is some overturning in both hemispheres that is clearly important, largely involving the tropics to subtropics, these subtropical overturning circulations. But the other part of it that needs to be explored a lot more, where there is potential for depositing heat at much greater depths in in the Western part of the Pacific, particularly in association with the boundary currents. The Australian Current, and the Kurishio Current. And there, there are clearly components that go down deeper than 1000m. And there's quite a lot of variability. Those are the most dynamic features in the ocean - the currents can be 1 m/sec. The same thing with the Gulf Stream. And so its in those regions also where I think we need to look harder as well... ...We don't know well what is going on. The sampling of the deep ocean is quite fragmentary. There are a couple of papers…. [may be referring to Purkey] suggesting that indeed there is evidence of warming at greater depths. Generally [the heat] is permeating through. The oceanographers are not quite sure how this happens. The general thought is in the abyss, the deep part of the ocean, there's not much action there, and change is very slow. If its just conduction, not currents or convection moving stuff around then it should be a very slow process. There are things like tides, which are continually pumping the ocean up and down and at some places at greater depths are known to cause greater mixing which is probably important which may not be taken fully into account . And so it may be that there are ways and places where heat is mixed down more readily than others. It may not be everywhere. And some seasonality can come into play. That's certainly the case in the N Atlantic. The main convection that occurs in the ocean is where you get in winter these cold dry outbreaks and this large heat fluxes into the atmosp0here that cools the surface of the ocean and then that cool water sinks. And so there is this overturning within the ocean. And so in wintertime you can get this very large changes to a few km depth in association with those kind of events. …. But in general, especially with a warming climate, if you are warming the surface, its more buoyant and it tends to sit there and the ocean becomes more stable.... "
  49. Arctic Ice Volume is diminishing even more rapidly than Area
    I think you are radically understating the cumulative ice mass loss for Jan 1st each year in the Arctic. It is approaching a 70% drop in ice mass for the period 1970/79 to present. If extent has fallen by 35% [confirmed] and thickness decreased by 50% [confirmed] then one has lost 67% of the volume [Maths]. NASA will not disagree with that number: its theirs. 65% of extent left X 50% of depth = 32.5% of volume. So 67.5% loss in mass. more on www.carbonvirgin.com
  50. The BEST Kind of Skepticism
    I tried to download a sample chapter of Easterbrook's textbook but at 20 MB, it wasn't worth wasting bandwidth on. I wonder if it's worse than Rapp's textbook, and honestly, how does stuff like this get published?

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