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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 125801 to 125850:

  1. Measuring Earth's energy imbalance
    I said: "this levels of C02-equivalent" with "this" I refer to the current ones, now near 450 ppm.
  2. Measuring Earth's energy imbalance
    What is dirturbing is that more than half of the greenhouse warming is masked by aerosols. This doesn't imply: 1) A climate sensitivity much bigger than the commonly assumed value of 3ºC per doubling of CO2, maybe 6-7ºC per doubling of CO2? 2)There is a lot of forcing (I said forcing,not warming) "in the pipeline" from the greenhouse gases, that will emerge as the aerosol emissions drop(these will be regulated before CO2 because them are highly toxic)? I suspect that the "Dangerous Antropogenic Influence" treshold was passed long ago, because according to paleoclimate studies, this levels of C02-equivalent are more than enough to melt away ALL GREENLAND, ALL THE MOUNTAIN GLACIERS AND THE WEST ANTARCTIC ICE SHEET.
  3. Is the airborne fraction of anthropogenic CO2 emissions increasing?
    Humanity rules wrote: "It's hard for me to understand how the rate of absorption can become reduced or the system become saturated. Common sense would say if you were looking at the movement of a substance from one fluid to another (atmosphere to ocean) then the larger the gradient (in this case caused by higher CO2 conc in the atmosphere) then the faster the diffusion of material." You're right about the second paragraph there but you just might be missing one important point. In order for the airborne factor to increase, the flux of CO2 to oceans etc. does not need to decrease. In order for AF to stay constant, the flux needs to increase at the same rate as emissions. Therefore, even if the flux of CO2 from atmosphere to the oceans etc. increases, but slower than the emissions, the AF will increase. Actually, mathematically a constant AF is exactly what you would expect, if you had exponentially growing emissions combined with sinks, whose rate is linearly proportional to the concentration.
  4. A visual deconstruction of a skeptic argument
    What about the CO2 reaching it's greenhouse saturation effect at a much lower level, and that much of the "worrying" is by taking into consideration amplification by high level water vapor? Many skeptics completely agree about the increased 20th century CO2 levels likely to be anthropogenic, but it is the "complete theory" of amplification which is hard for many to swallow? The increased heat will cause evaporation and increased water vapor, but the vapor will be high cirrus clouds resulting in greenhouse effect, and not low typical clouds which result in overall cooling.
    Response: Obviously, I can't hit all skeptic arguments in the one page (or can I?). This article is addressing the specific argument that humans aren't causing the rise of CO2 levels in the atmosphere. Those other arguments are addressed elsewhere:
  5. Is the airborne fraction of anthropogenic CO2 emissions increasing?
    John, maybe you should say something about the IPCC model forecasts re fraction of CO2 in atmosphere? It would also be interesting to learn more about the reason for the different estimated trends (1.2 vs 3 %/decade). Is it only because of Knorr using a longer time series for his modeling?
  6. Is the airborne fraction of anthropogenic CO2 emissions increasing?
    FF, it's not necessary to measure emissions to know how much CO2 is produced by burning fossil fuels, we only need to look at the accounting of fuel production. For example, we know that global oil production is about 31e9 bbl/year. From that we can calculate the amount of CO2, after taking into account the fraction of the oil going toward non-fuel purposes ( http://numero57.net/?p=255 ). It comes out to about 10e12 kg of CO2 per year produced by burning petroleum. Similar calculations can be made for coal and natural gas.
  7. Is the airborne fraction of anthropogenic CO2 emissions increasing?
    Wrong isotope, nfw, try 12C to 13C.
  8. Is the airborne fraction of anthropogenic CO2 emissions increasing?
    Yes, there is another twist to this tale. Without looking into to too much right now, C14 which is created from fossil burning. Apparently it is able to be measured. I think I remember reading an article by Roy Spencer(big, important skeptic) questioning that research too! LOL. But that should be the next topic to explore. Back to the topic above. The Knorr paper concludes with "The hypothesis of a recent or secular trend in the AF cannot be supported on the basis of the available data and its accuracy." Doesn't this mean they don't understand what is going on. It continues that they need to know more about land use, well I say what about CO2 changes in the ocean, which hold many times over the CO2 of the ocean. They can likely fairly estimate the man-made CO2, and then they just work backwards to fill n the number.
  9. Is the airborne fraction of anthropogenic CO2 emissions increasing?
    FF, have you never heard of carbon isotope ratios? This allows for identification of sources of CO2.
  10. Is the airborne fraction of anthropogenic CO2 emissions increasing?
    Quote: ----- "[Fossil fuel combustion is calculated from international energy statistics. CO2 emissions from land-use changes are more difficult to estimate and come with greater uncertainty.]" Of course it should be very difficult, since CO2 molecules are identical and indistinguishable at that level of density therefore it behaves according to quantum statistics (particle indistinguishability of fermions and bosons) which deviates from classical maxwellian-boltzman particles which are distinguishable. Any claim to measure CO2 emission level from a specific source must be viewed with suspicion, since one cannot distinguish the CO2 that originated from source A or CO2 that originated from source B and so forth, since the particles are identical (statistical mechanics).
  11. Berényi Péter at 05:32 AM on 2 January 2010
    Understanding Trenberth's travesty
    I am sorry. It was not my intention to insult you personally. But there is one thing I firmly believe in. That's there is an ultimate reality. And there are also propositions that match this reality and if they do, they are called true statements. In other words truth does exist. Not just in our minds or discussions, but on its own right. This is why false statements like "the planet is continuously accumulating heat" "as observed by satellites" are annoying. For satellite measurements of energy flux imbalance are neither accurate nor precise. Let's be more specific. Satellite OLR (Outgoing Longwave Radiation) measurements are fairly reliable. They may have a large systematic error, that is, they are inaccurate in your terms, but they are precise indeed in the sense that random errors are limited. So they are good for determining trends, but nothing else. As derived from various satellite data there is a consistent 0.12 W/m^2 yearly decrease in OLR since 2003. In other words the effective temperature of Earth as seen from the outside has dropped by about 0.15°C during this six year period. Of course it does not mean much and it is especially loosely related to average surface temperature. However, effective temperature itself is a well-defined concept, even if it is too abstract for most practical purposes (it is the temperature of a uniformly heated black body having the same outgoing thermal radiation energy flux as the object considered). The absolute value is somewhere between -15°C and -19°C, depending on the season, the particular satellite set used and method calculated. On the other hand ASR (Absorbed Shortwave Radiation) as measured by satellites is not even precise. The reason is that reflected sunlight has a very complex spectral, spatiotemporal and angular distribution, and both satellite coverage and spectral resolution of measurement are insufficient to capture it precisely. If we knew both solar constant variations and outgoing radiation from earth for the entire spectrum and all spatial directions with sufficient precision, it would be easy to calculate the energy balance. But as for now, the noise, mainly from spatiotemporal and angular undersampling at higher frequencies is so huge, that the energy balance of earth is not measured this way in any reasonable sense. If anything can be said about the short wave reflectance history of earth, it is that it's fairly stable in this period (within measurement error bounds). At the same time solar constant is slightly decreasing due to an extended low in solar cycle, so one can not say that the rate earth gained or lost energy has changed significantly. Of course it does not say anything about the possible initial offset between OLR and ASR at TOA, but that's exactly my point. The energy imbalance is NOT measured by satellites. Climate model predictions are also unfeasible for calibrating offset errors in energy balance measurements. The whole point of measuring imbalance is to verify models in the first place, isn't it? We are left with OHC, can forget both satellites and models. Here is a preprint of the von Schuckmann paper: http://www.euro-argo.eu/content/download/49437/368494/file/VonSchukmann_et_al_2009_inpress.pdf I have two problems with it. 1. Why could not he give OHC estimates for the 0-700 m subset as well? This way his results would be directly comparable to NODC estimates. As it is, one wonders what physical mechanism can transfer so much heat below 700 meters without even touching the strata in between? Weird. 2. I don't like graphs where all the error bars are of exactly the same size. Number of Argo floats grew fourfold during the period 2003-2007. Coverage have had also improved. It would imply error bars shrinking approximately half their original size. However, the vertical line segments on the figure look more like uniform ornaments. Schuckmann does not elaborate much on these problems in the text either. It's also remarkable that until recently in parts of the ocean where stratification, hence density difference between the surface and 2000 m depth level was too large, Argo floats could not make profiling of the entire water column, so they were programmed to go no deeper than 1000 meters (otherwise they could not return to the surface). New models can perform better on a slightly increased cost. What it actually means is that 0-2000 m OHC estimate is considerably less accurate for this time period than 0-700 m estimates. There is also an aging problem with the pressure sensors. An ever increasing number of floats report negative pressure at the surface, up to 30% of them by now. Schuckmann also fails to mention these arcane details. You can read more about float problems in Argonautics #10 (July 2008), pp 7. Profiling to 2000 m Anywhere in the World Ocean: Advances with APEX Floats Stephen C. Riser, University of Washington http://www.argo.ucsd.edu/Argonautics10.pdf
  12. Skeptical Science housekeeping: Translations and Comments Feed
    John and Ari, Thanks for the feedback. I wasn't sure how well Google translator worked.
  13. It's cosmic rays
    Mizimi, it doesn’t matter what the purported mechanism of GCRs’ effect is--water vapor, cloud formation, or anything else. Once the changes in GCR level stopped (i.e., GCR level became constant), the resulting energy imbalance of the Earth must “immediately” have started to shrink as the Earth “immediately” started to heat and therefore radiate more to match the new, now constant, level of GCR--regardless of whether the GCR effect occurs via some additional mechanisms involving water vapor, and regardless of whether the higher level of GCR amplifies the effect of increased water vapor. But the Earth’s energy imbalance has not been shrinking. It has continued to grow, which means the cause of the imbalance has continued to grow, which means the cause cannot still be GCR, because GCR has been constant for half a century. It is impossible for the effect to lag this long. This is the same reason the effect of solar radiance’s increase up to the 1950s cannot lag this long. The same argument applies to any factor once it stops changing.
  14. A visual deconstruction of a skeptic argument
    Thanks John for a nice site! nofreewind evidently reckons that the vast majority of climate scientists are either incompetent or conspirators. Somehow s/he reckons the "most important foundations" and graphs "critical to acceptance of AGW" are readily 'deconstructed' or could be shown by him/her to be erronious. But not so: the errors belong to nofreewind - and there are many independent items of evidence of AGW (read the basic pages on this site, or on Prof Mandia's site . As John calmly points out, the airborne fraction is from observations - and the GC models cited in the IPPC reports look at many years for comparisons, from physical principles, not by "fit(ting) one year". If there is one basic foundation to AGW, perhaps it is the observation that atmospheric CO2 levels are steadily increasing, along with global human output (plus the 13C/12C and 14C/12C ratios) - and no respectable scientist would gainsay that. That the estimates of carbon fluxes from natural processes are uncertain is unimportant - the evident perturbations of the dynamic equilibrium by human activity are indisputable - and worrying.
  15. It's cosmic rays
    Recently I watched a lecture by Dr. Richard Alley, at the AGU (link below). He mentions a "Muschler et al. 2005" paper, with a very neat graph showing a distinct spike in cosmic rays during the Laschamp event some 40 thousand years ago, with no corresponding change in temperature at the same time. I could not find the paper, though. Could anyone help? (relevant part at 42:10 min) http://www.agu.org/meetings/fm09/lectures/lecture_videos/A23A.shtml
  16. Is the airborne fraction of anthropogenic CO2 emissions increasing?
    On a lighter note: Happy New Year to all of you. Be safe tonight.
    Remember that when driving, just as with climate, rate of change (in this case, of velocity) *does* matter.
  17. CO2 has been higher in the past
    Chris thank you for that excellent response. It seems apparent that past CO2 levels were driven by tectonism. Might be a little premature to assume the sole driver of extinction was climate response, but it's certainly plausible. I hear a lot about what makes CO2 go up. But isn't an understanding of what forces lower CO2 equally important? What are the mechanisms that make the CO2 drop? If it's falling temperature, what is causing the drop in temperature, and I'm speaking about over the Phanerozoic, not recent glaciation cycles?
    Response: This is an excellent question. A process that removes CO2 from the atmosphere is rock weathering - where chemical process convert CO2 in the air into other chemicals. This process takes thousands of years. However, rock weathering activity increases in higher temperatures (Walker 1981). This acts as a natural thermostat on climate. As the earth gets hotter, CO2 is scrubbed out of the atmosphere by the accelerated rock weathering and CO2 levels drop.

    On the downside, this process happens over geological scales so natural rock weathering isn't a short term solution. On the up-side, there is research into using artificially accelerated rock weathering to sequester carbon dioxide from coal plants (Kelemen 2008).
  18. Is the airborne fraction of anthropogenic CO2 emissions increasing?
    Humanity Rules @2: Again it seems unlikely that this system has been tipped over the edge by humanity insignificant input (0.025%). Cumulative human additions of C to the active carbon cycle since the pre-industrial era have been around 329Gt (C only). [CDIAC] That would be .766% of total C in the active carbon cycle, not .025%.
  19. Is the airborne fraction of anthropogenic CO2 emissions increasing?
    John: Nice treatment of an easily misunderstood (cough cough) topic. I'm constantly amazed by the steps "some people" will take to leap to a conclusion (i.e. the "therefore it must be zero" thing you mentioned).
  20. Is the airborne fraction of anthropogenic CO2 emissions increasing?
    If half of the carbon we produce is absorbed and as I remember about half of what we produce is from burning coal does that mean that if we stop burning coal the atmospheric carbon will begin to decline? Also is it possible that any reduction of carbon uptake by the ocean is a result of higher temperatures rather than saturation?
  21. Skeptical Science housekeeping: Translations and Comments Feed
    I have tried Google Translator a bit, and it doesn't seem to produce much understandable Finnish. Finnish language is quite difficult for such automatic translators. It could be used to get a draft translation which would then be corrected manually, but I'm not sure if that would be better or faster method than direct manual translation.
  22. Is the airborne fraction of anthropogenic CO2 emissions increasing?
    It's hard for me to understand how the rate of absorption can become reduced or the system become saturated. Common sense would say if you were looking at the movement of a substance from one fluid to another (atmosphere to ocean) then the larger the gradient (in this case caused by higher CO2 conc in the atmosphere) then the faster the diffusion of material. In terms of the sinks becoming saturated. We known the biosphere is absorbing more CO2 through evidence of he greening of the planet. This may be only trivial anyway, it seems the ocean is likely the greatest store of carbon according to this quote "It [the oceans] already contains an estimated 40,000 GtC (billion tonnes of carbon) compared with only 750 GtC in the atmosphere and 2,200 GtC in the terrestrial biosphere (IPCC, 1996)." http://web.mit.edu/energylab/www/pubs/overview.PDF Again it seems unlikely that this system has been tipped over the edge by humanity insignificant input (0.025%). This analysis does assume that the natural CO2 cycle has been in perfect equilibrium over this whole period of time. The need for correction for ENSO and volcanos suggests there isn't a steady natural state but a dynamic process. Can you imagine more so far unidentified factors which might be affecting this analysis?
  23. Is the airborne fraction of anthropogenic CO2 emissions increasing?
    Brief comment, I got tripped up looking at the above (10 gigatonnes) and referring back to the previous post (29 gigatonnes). I'm sure this is due to carbon being weighed here versus carbon dioxide being weighed in the previous post. I was also tripped up by the quotation from AR4: "There is yet no statistically significant trend in the CO2 growth rate... since 1958." That's kind of confusing because the growth rate of CO2 is increasing. I guess all I'm trying to say is that even this relatively straightforward stuff can be confusing if one isn't careful when reading it.
  24. A visual deconstruction of a skeptic argument
    John, you may want to add a note on volcanic CO2 here just to show how it compares to the rest of the CO2 system. Probably just a text note since .3Gton/yr isn't really going to show up on the graphics.
  25. Was there a Medieval Warm Period?
    Griffon1, some of the proxy records have decadal resolution or better for the MWP. Of course the MWP is long ago and our proxies cannot be as accurate as direct measurements we can make today, so some warmer periods might have existed. All we can say is the observations of the MWP do not give evidence to believe it was as warm as today.
  26. It's cosmic rays
    "The bottom line is even if these difficulties can be resolved and the causality link between cosmic rays and cloud formation is proven, all they'll find is the cloud formation 50 years ago is similar to now and has had little to no impact on the last 30 years of long term global warming." Not so; as I posted somewhere else on this site there are 2 factors here - cosmic radiation and water vapour. If CR remains essentially the same you can still increase cloud formation if WV concentration increases. Temperature rises from CO2 increases are 'amplified' by increased WV according to AGW hypothesis - which is confirmed to be ocurring in the lower troposhere by direct measurement. Work by the Danes has shown that CR's act more like a catalyst in that single particles can cause many nucleation events, so the effect becomes SO2/WV dependant if CR level is constant. There is a link to the website of the Danish Technical University on the page "Do cosmic rays cause clouds?" (#40) "Set loose by cosmic rays passing through the atmosphere, the electrons attach themselves to fragile clusters of sulphuric acid and water molecules. Their electric charges stabilize the clusters while more molecules join them. When the molecular clusters are big enough, the electrons can leave them in a stable state, and go off to encourage other clusters to grow. In other words, the electrons act as catalysts, which promote chemical action while remaining unchanged themselves. A single electron can make many attempts to grow clusters, even though it will fail if it leaves too soon. "
  27. There's no empirical evidence
    The section "CO Traps Heat" is suffering from a logical fallacy of Composition: http://www.nizkor.org/features/fallacies/composition.html The assertion is made that increasing CO2 and other GHG's absorb more long wave radiation and prevent it from escaping to space. This is well supported by Harries 2001 Figure 3C. Clearly assertion this is supported by both theory and measurement. The fallacy comes into play when applying this to the WHOLE of the outgoing long wave spectrum. Looking at Harries 2001 Figure 1B (not shown), the range 800-1000 cm-1 shows an increase in outgoing long wave that exceeds the decrease due to GHG's. This observation is also present in Griggs 2004 and Chen 2007. Harries 2001 attributes this increase over the range 800-1000 cm-1 to 'small residual ice crystals' not fully removed from the data due to field of view differences between the detectors. This assertion is not supported by the addition of the NASA AIRS satellite. Additionally, satellite measurements of total outgoing long wave radiation show an increasing trend with time (and CO2, although not causative). http://www.isprs.org/publications/related/ISRSE/html/papers/332.pdf This is critical because it calls into question the causative relationship between "CO2 traps heat" and "Our planet is accumulating heat" in the block diagram. This relationship must be solid if the alarming predictions of the climate science community are to be believed and the mitigation of climate change can be achieved through CO2 emission reduction.
  28. Skeptical Science housekeeping: Translations and Comments Feed
    John, You may have tried this already, but have you looked into Google translator? It translates the entire site for the reader. If you use WordPress, there's a widget you can install. I use it on my site. It has a Finnish translator. http://translate.google.com/#
    Response: If the results from Google Translator when I use them to translate other languages into English are any indication, it's not the most reliable of translators. It gives you the general gist but you get a lot of weird phrasings. I guess there's no substitute for human translation.
  29. Could CFCs be causing global warming?
    Thanks for the update, and I also appreciate the tone of this site.
  30. Understanding Trenberth's travesty
    #27...surely in order for the ocean depths to warm, the surface water must do so first and then be mixed with deeper layers. This surface warming should be apparent unless you are saying the heat is transported more or less instantaneously (in climate terms)??
  31. Water vapor is the most powerful greenhouse gas
    "Anthropogenic use of water is less than 1% of natural sources of water vapor..." Thus starts a paragraph about water vapor to state somewhat later: "Radiative forcing from anthropogenic sources of tropospheric water vapor is not evaluated here ..." How can some one come to the conclusion we are dealing with science here. By the way these statements are taken from the IPCC's 4th Assessment Report.
  32. A visual deconstruction of a skeptic argument
    Thanks for this John, very clear and neat. It has increasingly seemed to me that the genuine skeptics are really focused on just this issue. Ok, they are saying, we will grant you CO2 is a GHG, and we grant you humans are pumping it out, but what you people fail to understand is that good old mother nature will take care of it for us by absorbing the excess CO2 and doing something with it. As your graph clearly shows, this is not the case, and with land clearance, forest stress due to drought and high temps, and changes to oceans, the absorption of the excess is likely to decrease even as the rate of pumping out increases. Thank you for all your efforts in 2009, and may 2010 be a more hopeful year for us all.
  33. Berényi Péter at 14:38 PM on 30 December 2009
    Understanding Trenberth's travesty
    John, you miss the point. It's rather irrelevant if Trenberth is believing in "global warming" or not. To be sure, he apparently does not believe in the possibility of radiation budget imbalances on the order of 6.4 W/m^2 like you do. For this is what's "observed by satellites". But his alternative, "the TOA energy imbalance can probably be most accurately determined from climate models" is in no way better. It implies "correcting" the (mis)measured imbalance according to a model, then certifying the model by the imbalance found. Bit circular. It turns out however, that TOA energy imbalance can be and is measured after all. By Argo floats, not satellites. http://wo.jcommops.org/cgi-bin/WebObjects/Argo http://www.bodc.ac.uk/projects/international/argo/project_overview/ Indirectly, of course. It's elementary thermodynamics. Global OHC (Ocean Heat Content) "anomaly" should be nearly proportional to the time integral of the "TOA energy imbalance" (integrating incoming and outgoing flux difference for an epoch on the surface of the globe, that is). Both specific heat of water and its quantity on Earth are enormous. http://www.nodc.noaa.gov/OC5/3M_HEAT_CONTENT/ You can see on the NODC site that OHC is flat for the last five years. It also happens to be the time interval we have reliable data. For Argo coverage only reached a reasonable level at the end of 2003 (and was completed by 2007). Earlier "measurements" of OHC are guesswork. Flat OHC means zero imbalance. Incoming SW radiation is equal to OLR. No trapping. It's easy to see why. As atmospheric CO2 concentration goes up, upper troposphere gets drier (documented), overall IR optical depth constant. No "greenhouse effect". Models predicting imbalance are disqualified. Trenberth, unlike you, knows his stuff. He is referring to Argo findings. "The fact is that we can't account for the lack of warming at the moment and it is a travesty that we can't." The only problem is that he failed to put this fact into a press release. He dared not. Theor Appl Climatology DOI 10.1007/s00704-009-0117-x Trends in middle- and upper-level tropospheric humidity from NCEP reanalysis data Garth Paltridge & Albert Arking & Michael Pook Received: 21 July 2008 / Accepted: 4 February 2009 http://www.theclimatescam.se/wp-content/uploads/2009/03/paltridgearkingpook.pdf "it is important that the trends of water vapor shown by the NCEP data for the middle and upper troposphere should not be "written off" simply on the basis that they are not supported by climate models" That's it.
    Response: The planet's energy imbalance obviously isn't 6.4 W/m2 - it's more of the order of around 0.85 W/m2. Satellite measurements have low accuracy but high precision. In other words, they display a high uncertainty in the absolute value of the radiation budget but stronger precision in year to year variability. So the satellite data is constrained - either by climate models or by ocean heat data (or both) in order to calculate the absolute energy imbalance.

    So it's correct that the energy imbalance can be determined through the measurement of ocean heat. Note that the ocean heat figures you're refering to at the NODC site refers to ocean heat down to 700 metres depth. However, upper ocean heat content is subject to short term variability due to the exchange of heat between the upper waters and deeper regions. A more comprehensive analysis of the Argo data can be found in Global hydrographic variability patterns during 2003–2008 (von Schuckmann 2009) which constructs a map of ocean heat content down to 2000 metres. It finds a significant positive energy imbalance of 0.77 W/m2:


    Figure 2: Time series of global mean heat storage (0–2000 m), measured in 108 Jm-2.

    Lastly, please refrain from personal insults in future comments.
  34. A visual deconstruction of a skeptic argument
    >The airborne fraction is calculated from observations, not theory or models. Specifically, it's calculated from the total amount of human CO2 emissions and the measured amount of atmospheric CO2. Of course, unless I'm missing something big. I assume that CO2 growth rate is simply total CO2 growth rate and does not differentiate btw human vs natural. I was just saying an eyeball look tells me CO2 rose by a large amt during the El Nino, which correlates with natural temp.'s more than a human effect, and that 1990 CO2 growth rate decreased during a year when it appear global temps decreased. Also, why isn't the growth rate steady, if it is because man-made. Most of the times the science discussed here is over my head, but this appears to be a topic I can understand with simple common sense. And it is one of the most important foundations to the AGW theory/consensus.
  35. A visual deconstruction of a skeptic argument
    Here is where much of that IPPC AR4 diagram comes from, the first reference. Prentice et al (to keep your website tidy I used a link generator) Look at the big diagram on page 5 developed from tables on page 10. Remember what I said about the Pennsylvania Forests 2004 report, the forest stand size grew 33% in 9 years? Did the IPCC know that, how about the thousands of other different forests in the world that may have responded to CO2 increase and temp increase differently, add to that the rate of vegetation decay and the incalculable ocean temperature gradients, all those are just a start! Unfortunately you didn't deconstruct anything in this post. AND that graph is critical to acceptance of AGW "theory", and it is quite easily deconstructed, even by a complete amateur as myself. But of course, only a very small percentage of even scientific type even know about the Carbon Cycle just take it as face value as accepted consensus, when it is a backward working theory to fit a preconceived model.
  36. A visual deconstruction of a skeptic argument
    >The amount of CO2 being absorbed by nature hasn't been a fixed amount in gigatonnes. Instead, it seems to be closer to a fixed percentage (with interannual variability of course). As human emissions increased, the amount of CO2 being absorbed also increased. John, that is all 100% complete "theory". There is no way to prove or disprove that. However, you can easily create a model and work backwords...and make everything fit. We KNOW there has been a global temp increase since 1850. We KNOW that warming oceans release more CO2, whre does that fit in the model? It doesn't have to of course, if you are just creating a model to fit one year in time, like the IPPC AR4. Look at Trends in CO2. CO2 annual growth Maybe just a coincidence, but look at 1998 on right scroll bar. 1998 was the highest CO2 annual growth rate, it also was the large increase in temp, and isn't the El Nino because the oceans release extra heat? Look at 1992, wasn't that a year of crashing global temperatures? 1990-2009 The CO2 growth rate is way down. Certainly man is causing CO2 increase of some sort in the atmosphere, but what about the oceans? Each single degree of ocean temp will have a rate of CO2 exchage, surely I respect the IPCC when they state that that the flux estimations can be off by 20%!!! We only need it to be off by 1 or 2 % in one system and the entire model of man-effect is essentially nonsense. This is something that should be "modeled", but certainly we can't place the entire world in shackles and move our modern society back to the stone age on a theory. Reminds me of 1999! The entire world moved their pensions and savings into the stock market, it seemed like a no loose proposition. Models were created by Harvard geniuses, we couldn't loose. Same with the fancy mortgage derivatives. The common man always looses and my Grandma Susie with her CD.'s, who couldn't even find the business page, was the winner.
    Response: The airborne fraction is calculated from observations, not theory or models. Specifically, it's calculated from the total amount of human CO2 emissions and the measured amount of atmospheric CO2. For more info, see Comparing CO2 emissions to CO2 levels
  37. A visual deconstruction of a skeptic argument
    nofreewind, re 8Gt vs 29Gt, the first is the measure of just the C in CO2 (the more common convention), the second is the measure of the the C plus the O2. In other words, they are the same quantity by different metrics. (Just multiply 8 x 44/12.) Re the apparent contradiction of figures 1 & 2 by 3, you might want to check the work of William Ruddiman. CO2 and CH4 should have been on a downward track ever since the Holocene Climate Optimum of 8000 to 6000 years ago, but instead, both began slowly rising as figure 3 shows. The reason? Ruddiman points out that humans began adding CO2, CH4 and NO2 to the atmosphere when we developed agriculture and that addition really took off with the domestication of rice and the widespread creation of man-made wetlands. Ruddiman also postulates that the absorption of CO2 by reforestation in Europe and then the Americas in the wake of large scale reductions in human populations due to epidemics may have been a factor in the cooling of the Little Ice Age.
  38. A visual deconstruction of a skeptic argument
    John, I find your blog to be an authoritative source of sensible AGW arguments, but I don't understand how figure 3 is related to figure 1 & 2. In fact if you look deeper into the issue Figure 3 contradicts Fig 1/2. You come up with 29 Gt of man-made CO2 from fossil/land use change. I am confused, shouldn't that be 6.4 + 1.6 = 8.0 Gt? http://www.ipcc.ch/publications_and_data/ar4/wg1/en/figure-7-3.html This figure shows the scale a little better. http://www.mongabay.com/images/2006/graphs/co2_global_1750-2000.jpg But, nevertheless, the caption states "Gross fluxes generally have uncertainties of more than ±20% ". What that means is the carbon cycle numbers are complete estimates, likely the amt of CO2 from fossil burning is the most accurate of the estimates. Here is deconstruction of your argument in considering the Global Carbon Cycle as something more than an estimate. http://www.nrs.fs.fed.us/pubs/rb/rb_nrs20.pdf slow loader Go to page 19 (22) You will see that Stand-Size of Pa forests increased by 33% btn 1994 and 2005. WOW, that's good, likely helped along because of increased feeding from CO2. This kind of land use change is occurring throughout the entire world. This stand-size increase of 33% likely resulted in enormous changes in CO2 feeding, and more vegetation decay. Scientists should make best estimate guesses to this process, but as stated in the caption, "gross fluxes have uncertainties of +-20%". We know the IPCC states that about 50% of man-made CO2 is taken back in by the oceans/land use, but in reality, that is "working backwards" to fit their models that man is responsible for the measured CO2 increase. It can not be anything but working backwards to fit their climate model of AGW warming and CO2 increase. Then of course, if half of the 8 Gt (or even your 29Gt) is taken by by natural processes, then we have to think, why did CO2 rise when man was putting out only 4Gt or 29Gt? So if the oceans/land behaved in the same way, we would not have had any atmospheric CO2 rise until we reached the 1/2 threshold of where we are today? To read a better explanation of how this is all theory and working backwards I recommend googling, reading and studying, CO2 - The Houdini of Gases. So my interpretation is that if man is making 7 Gt of CO2 now, and nature takes back approx 1/2 or 3.5 Gt, it wasn't until about 1960 that man made 3.5 Gt so there should have been NO RISE in atmospheric CO2 until about 1960. Also, sorry for not formatting links, but is there an easier way to make a link here w/o using html formatting which i find cumbersome?
    Response: Apologies for the confusion - I'm specifically refering to 29 gigatonnes of carbon dioxide. When discussing the carbon cycle, the IPCC use the weight of carbon, not carbon dioxide. I've noticed some depictions of the carbon cycle use carbon, others use carbon dioxide - I decided to use carbon dioxide as I thought it would be less confusing. Bad call! I explain the process of converting carbon weight to carbon dioxide weight here.

    The amount of CO2 being absorbed by nature hasn't been a fixed amount in gigatonnes. Instead, it seems to be closer to a fixed percentage (with interannual variability of course). As human emissions increased, the amount of CO2 being absorbed also increased. Figure 7.4 in the IPCC AR4 shows a graph of the fraction of CO2 remaining in the atmosphere (‘airborne fraction’) since 1958 (the thick black line is the 5 year mean). Note that over this period, CO2 emissions have greatly increased:

  39. A visual deconstruction of a skeptic argument
    Re John's inline comment to RSVP, I think you have the absorbed vs remaining fractions reversed. Shouldn't that be 55% absorbed by the biosphere and ocean, with 45% remaining in the atmosphere? In other words, human emissions of CO2 account for around 220% of the measured increase in atmospheric CO2 -- 100% of the increase, plus another 120% that is absorbed. Or to look at it another way, the biosphere, ocean, and geologic weathering absorb 100% of natural emissions, PLUS 55% of human emissions.
  40. 1998 is not the hottest year on record
    NP @24 -- I haven't looked at the NASA estimates for Angola over the last 27 years. Hopefully you can ask someone who might know why there's a persistent anomaly there, or at least someone who will confirm your finding.
  41. Understanding Trenberth's travesty
    #25...a review of Ceres data product can be found here and here "In general, heat storage, solar insolation, and TOA SW reflected flux dominate the systematic errors. Almost all systematic errors appear as planetary heating in the global net balance. Some of the errors like diurnal sampling biases await final confirmation using combined global 1030 Terra, 130 Aqua, as well as 3-hourly and 1-hourly geostationary data sources for SW fluxes, and GERB 30-minute broadband data from METEOSAT for SW and LW flux diurnal cycles. When all errors are combined, CERES Terra SRBAVG Edition2 non-GEO global Net flux is 6.9 Wm-2 versus a predicted range of 1.3 to 6.1 Wm-2. The ERBE-like global net flux is 3.8 Wm-2 versus a predicted range of -3.1 to 1.7 Wm-2. The less accurate ERBE-like global net flux comes closer to zero. The reason, however, is not more accurate TOA fluxes, but fortuitous cancellation of errors of opposite sign. The ultimate goal is of course to get the right answer for the right physical reasons. For example, the improved CERES angular dependence models improve the accuracy of the equator to pole gradient of reflected SW fluxes, especially in polar regions. Now why do I not feel confident about quoted figures for TOA radiation budgets??
  42. Could CFCs be causing global warming?
    Couldn't the same line of lousy reasoning (not sure how a reviewer could miss that) be used to declare "global temperature has been dominantly controlled by the level of methane...", which rose raipdly through the 80's and 90's and has been mostly flat over the past decade (increasing only recently)? But...both can't be "dominant".
  43. Berényi Péter at 03:22 AM on 30 December 2009
    Understanding Trenberth's travesty
    John Cook at 2009-12-12 23:44 PM wrote: "Trenberth states unequivocally that our planet is continually heating due to increasing carbon dioxide. This energy imbalance was very small 40 years ago but has steadily increased to around 0.9 W/m2 over the 2000 to 2005 period, as observed by satellites" No, he states nothing like that, unequivocally or otherwise. What Trenberth actually says is this: "There is a TOA imbalance of 6.4 W/m^2 from CERES data and this is outside of the realm of current estimates of global imbalances (Willis et al. 2004; Hansen et al. 2005; Huang 2006) that are expected from observed increases in carbon dioxide and other greenhouse gases in the atmosphere. The TOA energy imbalance can probably be most accurately determined from climate models and is estimated to be 0.85 ± 0.15 W/m^2" He simply sets the satellite-measured radiative energy balance of 6.4 W/m^2 at the top of the atmosphere to the entirely different value of 0.85 ± 0.15 W/m^2 based on climate models. It is equivalent to the proposition that satellite measurements are useless in this respect, so one has no choice but to verify climate model predictions using data derived from the model itself. In this case however, one can NOT say that the value of 0.9 W/m^2 is "observed by satellites". Or can, provided true and false statements have equal right to be uttered. EARTH’S GLOBAL ENERGY BUDGET by Kevin E. Trenberth, John T. Fasullo, and Jeffrey Kiehl http://ams.allenpress.com/archive/1520-0477/90/3/pdf/i1520-0477-90-3-311.pdf
    Response: I'm quoting Trenberth from the opening paragraph of  An imperative for climate change planning: tracking Earth's global energy (Trenberth 2009):
    Given that there is continual heating of the planet, referred to as radiative forcing, by accelerating increases of carbon dioxide (Figure 1) and other greenhouses due to human activities, why is the temperature not continuing to go up? The stock answer is that natural variability plays a key role [1] and there was a major La Nin˜ a event early in 2008 that led to the month of January having the lowest anomaly in global temperature since 2000. While this is true, it is an incomplete explanation.

    And a few paragraphs further along:

    Given that global warming is unequivocally happening [2] and there has so far been a failure to outline, let alone implement, global plans to mitigate the warming, then adapting to the climate change is an imperative.
    The broader point I was trying to make is that Trenberth's out-of-context quote was being used to portray him as privately not believing global warming is happening. This is decidedly not the case as is clearly communicated in the peer review literature.
  44. The albedo effect
    There is a growing body of evidence that in equatorial latitudes trees induce symbiotic bacteria and certain chemicals into their transpiration streams which increase reflective cloud cover over tropical forests during the day which is the best time to promote cooling. Please see www.weforest.com and read the white papers and watch the videos on our pages there.
  45. A visual deconstruction of a skeptic argument
    re response to post #1: It's worth pointing out that a recent analysis [*] supports the conclusion that the airborne fraction of anthropogenic CO2 is increasing, and with a larger trend than Knorr 2009 indicates, 'though as with Knorr 2009, the uncertainty is quite large. C. Le Quéré et al. (2009) Trends in the sources and sinks of carbon dioxide Nature Geosci. 2, 831-836. http://www.nature.com/ngeo/journal/v2/n12/abs/ngeo689.html
  46. 1998 is not the hottest year on record
    Steve L @ 23 I have had a look at NASA's data and the current hot spot in Antarctica started around 1982, about the same time as the hot spot in Angola. That is based on 27 years of data and therefore I would argue reflects climate and not simpy weather. Also, with regard to which year has been hottest, taking into consideration the accuracy of the temp measurements ( +/- about 0.1 degree C according to NASA ) the years 1998, 2002,2003, 2005, 2006 and 2007, can be regarded as being of similar temperature.
  47. A visual deconstruction of a skeptic argument
    John, this article looks impervious to skeptic remarks, however, according to the numbers, ocean, land and vegetation absorb more CO2 than they put out. How then can any CO2 have remained if this process has been going on for millions of years?
    Response: Kudos for noticing! Ocean, land & vegetation are absorbing more than they emit because nature is partially absorbing the CO2 we're emitting. In other words, nature is trying to undo the impact we're having on the climate (I don't mean that in a mystical Gaia fashion - it's just a consequence of the nature of carbon sinks). Currently, nature absorbs about 45% of human CO2 emissions. The fraction that remains in the atmosphere, around 55%, is referred to as the "airborne fraction".

    One of the big questions concerning the carbon cycle is whether there's any trend in the "airborne fraction". Eg - is nature losing the ability to absorb our CO2 emissions? There have been some studies indicating that the oceans are getting saturated (Quéré 2007, Schuster 2007, Park 2008). On the other hand, an analysis of the airborne fraction has found a slight increasing trend in airborne fraction of 0.7 ± 1.4% per decade but the result is statistically insignificant (Knorr 2009). In other words, the status of the airborne fraction is pending.
  48. Skeptical Science housekeeping: Translations and Comments Feed
    "Many thanks to Ari and Kaj for all their hard work (I'll try to keep my verbosity down in future posts to make things easier for you)." It's our pleasure. Thank you for making such an amazing resource. We are just glad that we can help in offering it also to (Finnish) people who don't understand English. Oh, and on the verbosity thing, don't hold back, keep giving us challenges. ;)
  49. 1998 is not the hottest year on record
    #22. I think you might instead ask John Cook, or re-read the post. In the post, John writes that he would rather people focus on energy imbalance, but he thought it was also worthwhile to show that one specific year (1998) likely wasn't the warmest. It is only estimated to be the warmest in one case because of the limited spatial distribution of sampling in that case. You can compare the NASA GISS map in Fig 2 to the top panel of Fig 1 and see that the probable hottest year was 2005 owing to all that warmth in the polar regions where HadCRUT doesn't sample. That's what the maps are about. Re-read the post and tell me if you agree.
  50. 1998 is not the hottest year on record
    Steve L @19 "For rates of global warming (large spatial scale), somewhere over 15 years is recommended in this post"... So I can disregard NASA's temperature map above as it reflects weather and not climate ? In that case, why was the map posted here?

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