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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 125651 to 125700:

  1. Polar bear numbers are increasing
    UNPRECEDENTED LOSS OF SEA ICE RENEW CONCERNS FOR SURVIVAL OF THE WORLD'S POLAR BEARS July6,2009(Copenhagen,Denmark) At the 15th meeting of the IUCN Polar Bear Specialist Group...renewed the conclusions from previous meetings that the greatest challenge to the conservation of polar bears is ecological change in the Arctic, resulting from global warming. "The Western Hudson Bay subpopulation has been on the declilne for almost two decades...the body condition in polar bears is linked to the availibility of sea ice and time of spring break-up; and that when sea ice is available for less time, body condition declines ultimately affecting reproduction in adult female bears..."... ...Reviewing the latest information available, the PBSG concluded that one of 19 subpopulations is currently increasing, three are stable and eight are declining. For the remaining seven subpopulations, available data were insufficielnt to provide an assesment of current trend. The subpopulation increasing is located in Canada's high Arctic, an area that has not seen as much loss of sea ice as others, suppporting the Group's analysis of the critical relationship between the health of polar bears and the amount of sea ice... The IUCN (International Union for the Conservation of Nature and Natural Resouces) Polar Bear Specialist Group...each of the five circumpolar nations that signed the International Agreement for the Conservation of Polar Bears of 1973 - Canada, USA, Greenland(Denmark), Finland and Russia... polarbearsinternational.org Press Release ...(Nov3,2009): For the first time, researchers are studying...the summering ecology of polar bears of the southern Beaufort Sea who choose to migrate north to the sea ice of the polar basin when the winter ice pack melts, rather than return to the shores of Alaska... ...ice breaker expedition... ..."Polar bears need appropriate ice to hunt and survive. Young, thin ice can break up or disappear in a storm and older ice can actually be too thick for the bears to hunt seals..."... Polar Bears International
  2. Is the airborne fraction of anthropogenic CO2 emissions increasing?
    But Ralph, you're just wrong. Factually wrong. Empirically wrong. Seriously wrong. Go read Pierrehumbert's book. It's free. It's online so it's easy to search for key words.
  3. Is the airborne fraction of anthropogenic CO2 emissions increasing?
    I look at it this way - the earth surface area is about 200 million square miles. That means each CO2 sensor must account for about the equivalent of one million square miles (I think there are only 200-300 long term datasets). So, this is just one dataset for all of Alaska and California and Texas combined (almost). As for clouds - I think the clouds indicate the LACK of uniformity of density in the atmosphere since they show visually how different the atmosphere can be - regardless of whether you consider water a molecule or not (it is). All I am saying is we would need millions of data sensors to get a handle on the total weight of CO2 in the atmosphere and the data we have is just too weak right now.
  4. CO2 measurements are suspect
    Theo, a "single regime of measurement in the atmosphere (all the way up)" is not needed. Measurements from spacecraft are calibrated against measurements from aircraft and ground stations. Routinely. And different methods of measuring even at ground stations are calibrated against each other. Ditto for aircraft measurements. New spacecraft often are launched while the spacecraft they are replacing are still in service, so that the new spacecraft's measurements can be calibrated against the old spacecraft's measurements. You don't read about such things in the newspaper or even on blogs, because it's part of the mundane, routine, standard, detail of empirical science.
  5. CO2 measurements are suspect
    Theo, see my 13:49 PM on 4 January comment on the Is the airborne fraction of anthropogenic CO2 emissions increasing? thread. See also dhogaza's comments in that thread. "Well mixed" is not an assumption, it is a longstanding observation.
  6. Is the airborne fraction of anthropogenic CO2 emissions increasing?
    Ralph, you are incorrect that there are "no data on CO2 close to the Earth." Just no data at that level of the atmosphere from AIRS. There are lots of data at that level from ground stations and aircraft, all over the world. The fact that CO2 is well mixed is not an assumption, nor a theoretical prediction. It is an observed fact dating back to at least the U.S. military's measurements in the 1940s. The number of observing stations, and their distribution, have been settled on as a satisfactory sampling, based on those empirical observations. Read dhogaza's comments in this thread; the variation in the mid-troposphere is tiny--less than half of the already-tiny 3% that you claimed. That variation is inconsequential to the big picture of CO2's global warming effects. Climatologists and atmospheric scientists of course got all excited about that tiny variation, because that is their narrow, microscopic specialty. Why do you persist in insisting that clouds are indicators that the atmosphere is uniformly dense? dhogaza already explained to you that clouds are not made of gas molecules, so their distribution and even existence is not evidence of gas molecules being unevenly distributed. If you want more detailed explanations, blogs are not the right place. Go look at Ray Pierrehumbert's book on planetary atmospheres, to which I pointed you earlier.
  7. CO2 measurements are suspect
    Tom Dayton, Thanks much for the reference to Pierrehumbert's book.
  8. CO2 measurements are suspect
    Chris, Mizimi, and Tom Dayton, Thanks for a really interesting discussion of airborne CO2 concentrations. As a philosopher and not a scientist, I am more interested in assumptions that are made when measurements are taken. Chris' remarks seem to assume that CO2 is well-mixed in the atmosphere and that, for that reason, the fact that the measurement stations are located on the surface will provide an accurate picture of airborne CO2 concentrations. Now, I wonder if there are airborne measurement stations and if they are distributed throughout the atmosphere in a way that would make them as effective as the ground based stations. I doubt that they are because they would be very expensive. Satelites are very expensive too and they would use a different technique of measurement. So, my tentative conclusion is this: it seems that there is not a regime of measurement in the atmosphere (all the way up) that could serve to confirm the hypothesis that CO2 is well-mixed throughout the atmosphere. Am I right?
  9. Is the airborne fraction of anthropogenic CO2 emissions increasing?
    Theo, I don't know if there is a single article describing all the methods in detail, because different methods are used by spacecraft versus aircraft versus ground stations. But a description of the collection method on Mauna Loa is on NOAA's site. And on the AIRS site, click on the two links in the section titled "Measuring CO2 from Space with AIRS."
  10. Is the airborne fraction of anthropogenic CO2 emissions increasing?
    There is a 3% variation in the mid-troposhpere (5 miles) and no data on CO2 close to the earth. If the atmosphere is mixed well in that layer it is surely less well mixed at lower levels. If you are seeing a rise in CO2 levels how would you really know whether you were in a density wave or not? And as for clouds which reside at about 2 miles - they are indicators that the atmosphere is not uniformly dense. It appears that real CO2 data would be needed from literally millions of sampling points at varying strata not just the 200 or 300 stations that are used.
  11. Is the airborne fraction of anthropogenic CO2 emissions increasing?
    Tom Dayton and cbrock, thank you for answering my question, putting me to materials, and carrying on the conversation. If I may ask another, could you point me to an article on techniques of measuring airborne carbon dioxide concentrations?
  12. Is the airborne fraction of anthropogenic CO2 emissions increasing?
    Tom Dayton - the graphic from NASA depicts widespread, highly varying concentrations of CO2
    On what did you base your "highly varying" comment? Was it because they used a full spectrum of color (blue to red) to portray the +/- 1.3% variance (with most of the globe falling into a range of < 1.3% variance), or is it because you actually think the +/- 5 PPM range is really "highly variant"? Just curious.
  13. Is the airborne fraction of anthropogenic CO2 emissions increasing?
    If that were true then all molecules of any type would be equally distributed - including clouds. And since clouds are here and there - so must be molecules.
    Clouds are made up of droplets of water or small bits of ice, not individual molecules of H2O, so your comment regarding clouds is irrelevant.
    Also, the NASA CO2 map belies the idea that CO2 is evenly distributed.
    and
    http://sustainablog.org/files/2008/10/nasa_co2map.jpg
    Depends on your definition of "evenly distributed". The NASA AIRS plot you reference has a scale of 376-386 PPM, or 381 +/- 5 PPM. That's 381 PPM +/- 1.3%. That's extremely close to "evenly distributed". The press release is actually a bit weird, the AIRS data quantifies the "lumpiness". It's always been *known* that it takes time for CO2 (and other gasses) to become distributed by wind etc throughout the atmosphere - if you crack a tank of pure CO2 obviously the CO2 concentration near the tank will be higher than the average in the atmosphere. But once the tank runs out, the CO2 will rapidly disperse and that's it. So this isn't new knowledge at all. It's just quantification of how close to being 100% well-mixed the atmosphere is. We can measure it now, couldn't before, that's all.
  14. Is the airborne fraction of anthropogenic CO2 emissions increasing?
    NASA CO2 graphic http://sustainablog.org/files/2008/10/nasa_co2map.jpg Tom Dayton - the graphic from NASA depicts widespread, highly varying concentrations of CO2 - if CO2 was diffused evenly the color on the globe would be just one color.
  15. Is the airborne fraction of anthropogenic CO2 emissions increasing?
    ralphiegm, observations trump what you or anyone else "thinks." Also, you are incorrect that all kinds of molecules must be distributed to the same degree; just one example is water vapor's low concentration in the stratosphere versus lower, versus CO2's much more even concentration across those altitudes. Read the above comment by cbrock, and click the links in my above comment.
  16. It's cooling
    John Cook: Comparing the OHC results from the: 1)Upper 700 meters : 0.089 Wm^−2 (data source:http://climexp.knmi.nl/daily2longer.cgi, and the trend obtained in EXCEL) 2)Upper 2000 meters: 0.77 ± 0.11 Wm^−2 It is clear that the heat was sequestered in the Deep Oceans by the Termohaline Circulation, and that explain why the SST warming trend was near zero between 2003 and 2008. From this numbers is clear that if the Termohaline Circulation Shut Down then a BLAST OF HEAT will occur in the Upper Ocean and Atmosphere. Is there any current Climate Model of how much the warming will accelerate if the Termohaline Circulation Shut Down?
  17. Is the airborne fraction of anthropogenic CO2 emissions increasing?
    I think the idea that CO2 is diffused evenly througout the atmosphere is bogus. If that were true then all molecules of any type would be equally distributed - including clouds. And since clouds are here and there - so must be molecules. Also, the NASA CO2 map belies the idea that CO2 is evenly distributed. So the sampling for CO2 must be worldwide - not from few hundred stations.
  18. Is the airborne fraction of anthropogenic CO2 emissions increasing?
    Theo Goodwin: It is sometimes assumed by non-scientists that heavier gas molecules must be found closer to the earth's surface. However, for long-lived species such as CO2, atmospheric mixing (air motions) very effectively stirs up all the gases together so that they are not vertically separated. As one gets in the upper atmosphere (at very low pressures, approaching space), this is no longer true, but this region represents a tiny fraction of the mass of the atmosphere. This does not mean that all gases are perfectly evenly mixed, however. Obviously, near CO2 sources the concentrations will be higher, and near CO2 sinks (such as growing vegetation), the CO2 will be lower. So the end result is a patchiness to atmospheric CO2. There is a seasonality to this, since most vegetation is in the northern hemisphere. This seasonal cycle of CO2 is referred to as the "breathing" of the planet as the vegetation takes up CO2 during the growing season and gives it up during the fall and winter. The CO2 measurements report whatever the CO2 concentration is at a given place and time. Most of these measurements are extremely accurate and precise--a great deal of effort goes into assuring constant calibration standards and reproducibility. One has to average the CO2 measurements over the annual cycle and over the globe to get the global mean value. Hope this helps.
  19. Is the airborne fraction of anthropogenic CO2 emissions increasing?
    Theo Goodwin: CO2 is well mixed throughout the atmosphere--horizontally and (all the way up to the stratosphere). See the Skeptic Argument CO2 Measurements are Suspect. In addition to John's original post there, read the comments by Chris, John's "Response" in the green box within comment 16, and the new comment by me.
  20. CO2 measurements are suspect
    An AIRS press release noted that the AIRS data "complement existing and planned ground and aircraft measurements of carbon dioxide." Complement, not replace, because different tools measure CO2 in different vertical locations. More info on AIRS is available on the AIRS web site. The AIRS data for a recent two weeks can be seen on an interactive, rotating globe on JPL's "Eyes on the Earth 3D" web site. (On my Mac, it works properly in the Safari browser but not in Firefox; but my installation of Firefox doesn't work quite right, so it might be fine on your computer.) At the top left of the page, click the "AQUA" button. Then on the right side of the page, click the "CO2" button to show CO2 levels in the mid-troposphere as colors on the globe. The dates shown are above and to the left of the globe. Now drag the globe to rotate it. Click on the AQUA satellite to see the AIRS instrument. Discussion of CO2 being well mixed is on page 79 of Ray Pierrehumbert's book Principles of Planetary Climate, which is available free on line (and will be published in paper in 2010).
  21. Is the airborne fraction of anthropogenic CO2 emissions increasing?
    Could someone please extend some charity to a philosopher and tell me what assumptions are made when direct measurements of carbon dioxide concentrations in Earth's atmosphere are made? For example, is it assumed that CO2 molecules are distributed randomly throughout Earth's atmosphere including the stratosphere? Or is there some reason to believe that CO2 particles collect mostly within the first mile or the first 8 miles or whatever of the Earth's atmosphere?
  22. The physical realities of global warming
    The graph posted in response to #10.WAG (26 November, 2009) is one of the best Global Warming Trend graph I ever seen. Now, how will be the graph INCLUDING 2009, that will surely be warmer than 2007 and 1998? As 2009 data would be the final piece in the grave of the "Global Cooling" nonsense, it should be e-mailed to all deniers inmediately after the December GISS and hadCRU are published. By by, Global Cooling!
  23. Berényi Péter at 09:48 AM on 3 January 2010
    Understanding Trenberth's travesty
    One more thing. If you have a closer look at the figure (Global Ocean Heat Storage 0-2000 m) you have shown us from von Schuckmann 2009, you may notice a considerable jump at the turn of 2006/2007. In just two months OHC went up by 8x10^7 J/m^2. It is huge. It requires some 15 W/m^2 surplus heat flux for an extended period (9 weeks). Even taking into account the error bars, it's 15 ± 6.5 W/m^2. It is 6% of the heat flux coming from the sun to the surface. If this much heat is transferred to the ocean, it would cool down the ENTIRE atmosphere by 8°C. In midwinter. And he says most of the marine heat gain occurred in the North Atlantic. If I had three legs it would not pass unnoticed.
  24. Is the airborne fraction of anthropogenic CO2 emissions increasing?
    sorry... Probably there are other causes of greater relevance than are being systematically ignored, not only by the scientific community, but by the IPCC, for example, rapidly growing trend of forest fires directly proportional to the exorbitant growth population in the world. Read news about a few months ago published: + http://www.cubanuestra.nu/web/article.asp?Artid=15784 More information on this site (by autor): + http://calentamientoglobalacelerado.net/alerta.htm
  25. Models are unreliable
    "If this is the case, then the temperature record shown is a slight underestimate of actual warming..." Are you implying that IPCC uses temperature records that aren't published and we don't have access to? None of the surface air temperatures or the satellite temperature records that I'm aware of come close to showing the temperature increases in figure 1. Certainly HadCRUT reflects less than half the increase in figure 1.
    Response: "Are you implying that IPCC uses temperature records that aren't published?"

    Not at all. The IPCC TAR use the HadCRUT record, NCDC and NASA GISS. They just don't indicate which of these records are used in Figure 1 above. As for the trends in Figure 1, just eyeballing the graph, it looks like the trend in the last few decades is 0.2°C which is consistent with all three temperature records.
  26. Models are unreliable
    The IPCC curves that you reproduce in figure 1 always looked wrong to me. Granted they're hard to read, but they show "observed" temperatures increasing much more than actual measurements from Hadcrut3, GISS,etc.....by a factor of 2-3 in some periods. e.g. 1975-2000. I think these were published in "Nature" years ago and I recall there was controversy about them then.
    Response: I'm having trouble determining which is the observed temperature record in Figure 1 as the IPCC TAR doesn't say which explicitly for that particular graph. I'm guessing it's the HadCRUT3 record as that seems to be the favoured record used throughout TAR. If this is the case, then the temperature record shown is a slight underestimate of actual warming as the HadCRUT record excludes some of the regions on earth that are warming the most.
  27. Arctic sea ice melt - natural or man-made?
    The RV anomaly doesn't cause anticyclonic circulation (in the totality of the flow anomaly of the PV anomaly) about the cyclonic PV anomaly but to some degree it spatially restricts the strength of the cyclonic circulation.
  28. Arctic sea ice melt - natural or man-made?
    NOTE I'm now using @ as a substitute partial derivative symbol for ease of typing and readability. Correction/clarification: For a reference frame that rotates with the planet (or star, etc.) u = x component of velocity v = y component of velocity For flow patterns along surfaces (in x,y,z coordinates, surfaces of constant z; otherwise, for x,y,p coordinates, surfaces of constant p (isobaric surfaces), or for x,y,q coordinates, where q is potential temperature, using surfaces of constant q (isentropic surfaces), and where 'vorticity' refers to the vertical component of the vorticity vector, the vorticity is equal to the sum (two horizontal dimensions) of variations over horizontal distances of the horizontal component of flow perpendicular to those direction; RV (relative vorticity) = @v/@x - @u/@y, f = planetary vorticity = the coriolis parameter = the vertical component of vorticity associated with planetary rotation, AV = absolute vorticity = RV + f where horizontal distances x and y are the horizontal components of distances along the surfaces within which the vorticity is being determined; when x and y are rotated so that the x direction is locally aligned with the flow, @v/@x becomes the orbital (curvature) vorticity (the vorticity associated with curvature of streamlines), and - @u/@y becomes the shear vorticity (the vorticity associated with changing the wind speed or direction across streamlines) For a pattern of flow that is like rigid solid-body rotation, @v/@x = - @u/@y = 1/2 * vorticity = shear vorticity = orbital (curvature) vorticity = angular velocity of rotation = angular frequency The circulation* (*not to be confused with the more general usage of the term) along a closed perimeter (the integral over length along the perimeter of the component of velocity locally parallel to the contour, taken to be positive in the counterclockwise direction) is equal to the integral of vorticity over the area enclosed. Circulation = line integral of (component of velocity parallel to the line in the counterclockwise direction) area-average vorticity = circulation/(area enclosed) If the perimeter follows a closed loop streamline (streamlines are parallel to the wind velocity), then the average of the counterclockwise speed over the length of the streamline is equal to the area-average of vorticity within the streamline multiplied by the area and divided by the length of the streamline. Circular streamlines will be centered on a circularly-symmetric vorticity field (which maintains symmetry out to infinitiy) if the flow is nondivergent (streamlines can only be assigned to a nondivergent component of the flow). For a circular streamline of radius r: Circulation = 2*pi*r * (circumference-average speed) = pi*r^2 * (area-average vorticity) (average speed) = r/2 * (average vorticity) Note that for two different closed-loops that completely envelope a region of nonzero vorticity which is surrounded by a zero vorticity field, the circulation about each loop is the same and hence the average speed (component along the loop) will vary among the loops in inverse proportion to loop length. Hence, the average speed about such loops which are circular is inversely proportional to the radii. If such circular loops are centered about a circularly-symmetricy vorticity field which goes to zero within a radius smaller than the loop radii (and remains at zero to infinity), then the loops are streamlines and the average speed on each loop is the speed at all points on each loop. Outside a circularly-symmetric region of nonzero vorticity, the orbital (curvature) vorticity and shear vorticity cancel each other. (There is a planetary circulation for planetary vorticiy, relative circulation ('circulation' by default) for RV, etc.) Linearly-superpositional vorticity fields and circulation values are associated with linearly-superpositional wind fields. Thus, if the total wind velocity = V1 + V2 ..., then the total RV = RV1 + RV2 ..., etc. Hence, any circularly-symmetric vorticity field has a set of concentric circular streamlines that are contours of that vorticity field's streamfunction (whether or not there are other nonzero vorticity fields at any location); the streamfunctions of multiple vorticity fields can be summed to find the total streamfunction. A particular component of a vorticity field can be called a vorticity anomaly, and a vorticity anomaly has a flow-pattern anomaly (streamfunction anomaly). Within a circular homogeneous RV anomaly, the anomaly flow pattern acts like rigid-body rotation. True that: 1. a point or homogeneous circular RV anomaly is mathematically associated with a wind anomaly which forms circular streamlines centered on the RV anomaly with wind speed being proportional to 1/r outside the RV anomaly, where r is the distance from the center (such a relationship has curvature/orbital vorticity same sign as the RV anomaly which is equal and opposite to the shear vorticity). AND for a homogenous RV anomaly along a line or constatn-wideth band, the velocity anomaly outside the line or band does not vary with distance from the line or band and is everywhere parallel to the line/band. HOWEVER (and this is where I may have made a mistake earlier): For a barotropic PV anomaly (with flat bottom topography) that is either a point-anomaly or has a 'hard edge' (as opposed to a sinusoidal or sufficiently-gradually tapered distribution (?), etc.), assuming geostrophic balance, the velocity field will generally have to decay in magnitude more rapidly with horizontal distance. This is because, for example, a cyclonic PV anomaly must have a low pressure anomaly associated with it. The pressure can't have a sharp jump within infinite geostrophic winds; thus, the pressure must decline gradually going towards the PV anomaly, even in the region of zero PV anomaly; this requires a RV anomaly of opposite sign to surround the PV anomaly (there will still generally be an RV anomaly of the same sign within the PV anomaly, and the circulation along closed loops (closure at infinity for infinite band/line PV anomaly) will still be cyclonic at any distance from the PV anomaly, but will decrease in strength outward from the PV anomaly due to the oppositely-signed RV anomaly required by geostrophic balance and a continuous pressure distribution. In the case of a baroclinic PV anomaly that is either a point or otherwise 'hard-edged' or not-sufficiently tapered, with limited extent vertically and horizontally, similar arguments apply. Along the isentropic surfaces that intersect the PV anomaly, for a cyclonic anomaly in geostrophic balance, the spacing between isentropes must decrease approaching the anomaly even outside the anomaly, so that there is a positive stability anomaly, which requires an anticyclonic RV anomaly outside a cyclonic PV anomaly in order for the PV anomaly to be zero outside the nonzero PV anomaly. Above and below a cyclonic PV anomaly in geostrophic balance, the isentrope spacing anomaly must be negative, requiring a cyclonic RV anomaly, as previously described. Qualitative arguments suggest a pattern with something like a conical shape with upper and lower cones that have vertices at/within the PV anomaly; outside the region of nonzero PV anomaly, for a cyclonic PV anomaly: within the cones, the stability anomaly is negative and the RV anomaly is cyclonic (as is generally the RV anomaly within the PV anomaly), while outside the cones, a ring of anticyclonic RV anomaly surrounds the PV anomaly along with a positive stability anomaly that generally extends through the PV anomaly. The RV anomaly doesn't cause anticyclonic circulation about the cyclonic PV anomaly but to some degree it spatially restricts the strength of the cyclonic circulation.
  29. Measuring Earth's energy imbalance
    I said: "this levels of C02-equivalent" with "this" I refer to the current ones, now near 450 ppm.
  30. 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.
  31. 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.
  32. 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:
  33. 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?
  34. 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.
  35. Is the airborne fraction of anthropogenic CO2 emissions increasing?
    Wrong isotope, nfw, try 12C to 13C.
  36. 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.
  37. 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.
  38. 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).
  39. 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
  40. Skeptical Science housekeeping: Translations and Comments Feed
    John and Ari, Thanks for the feedback. I wasn't sure how well Google translator worked.
  41. 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.
  42. 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.
  43. 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
  44. 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.
  45. 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).
  46. 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%.
  47. 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).
  48. 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?
  49. 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.
  50. 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?

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