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Ocean heat content increases update

Filed under: — gavin @ 21 May 2010 - (Español) (Italian) (English)

There is a new paper in Nature this week on recent trends in ocean heat content from a large group of oceanographers led by John Lyman at PMEL. Their target is the uncertainty surrounding the various efforts to create a homogenised ocean heat content data set that deals appropriately with the various instrument changes and coverage biases that have plagued previous attempts.

We have discussed this issue a number of times because of its importance in diagnosing the long term radiative imbalance of the atmosphere. Basically, if there has been more energy coming in at the top than is leaving, then it has to have been going somewhere – and that somewhere is mainly the ocean. (Other reservoirs for this energy, like the land surface or melting ice, are much smaller, and can be neglected for the most part).

The main problem has been that over time the network of XBT probes and CTD casts has been replaced by the Argo float network which has a much greater coverage and more homogeneous instrumentation. However, connecting up the old and new networks, and dealing with specific biases in the XBT probes is difficult. An XBT (eXpendable Bathy-Thermograph) is a probe that is thrown off the ship and whose temperature readings as a function of time are transferred to a profile in depth from knowledge of how fast the probe falls. Unfortunately, this function is a complicated one that depends on the temperature of the water, the depth, the manufacturer of the probe etc. Various groups – working with the same basic data – have shown that there were biases in the XBT associated with incorrect calibrations and have attempted to make better corrections.

The latest paper is a consensus effort from many of the people involved in the previous work and shows how robust the recent decades warming of the ocean has been. Indeed, the ‘best estimate’ for the changes in the top 700m seems to be a greater warming than seen in the NODC data and more than even the models were suggesting:


Update (May 2012): The scaling of the model output on the original graph was incorrect, and the graph has been replaced with a corrected version. The original can still be found here.

One thing that is interesting to note is that the interannual variability – particularly in the transition period between the two observing systems (1995-2005 say) is very dependent on exactly how you do the corrections, while the longer term trend is robust. This ties in directly with comments by Kevin Trenberth in this recent paper and in an accompanying commentary to the Lyman paper that while the energy budget changes over the long term are explainable, the changes over short time frames are still very difficult to quantify.

As usual, this is unlikely to be the very last word on the subject, but this is more evidence that the planet is basically behaving as the scientists think it is. And that isn’t necessarily good news.


169 Responses to “Ocean heat content increases update”

  1. 1
    sidd says:

    Thanx for the review. Any hope of better data for the deeper ocean soon ?

  2. 2

    There is no mention in the paper of latent heat from the melting of Arctic sea ice. Moreover, it seems that the rise in heat content has paused since the year 2000 BCE. Could this pause be due to the thinning of the Arctic sea ice causing the additional heat to be absorbed by the latent heat of melting ice?

    Cheers, Alastair.

    [Response: No. Work out the numbers. - gavin]

  3. 3
    jacob mack says:

    good post and references.I too wonder about the calibration methods and deeper depth analysis. 700meters is very telling just the same.

  4. 4
    Edward Greisch says:

    WOW! No wonder it is so cloudy and rainy here.

  5. 5
    MarkB says:

    Any ideas (or papers) on the mechanisms that cause the short-term variability, such as the large leap in the early part of the decade apparent in both estimates?

  6. 6
    Toppy says:

    When the trade winds return to normal over time, these values will change dramatically. And that isn’t necessarily good news if you believe the values will keep going up.

    http://www.nwfsc.noaa.gov/research/divisions/fed/oeip/EcInFigs/ecinfigfour.jpg

    Very strong trade winds and prolonged La Nina episodes in the near future is all that is required to reverse the trend.

    [Response: Whatever you say.... But given that the last La Nina was pretty big and that didn't have a particularly marked effect, forgive me if I rely more on basic conservation of energy. - gavin]

  7. 7
    Norbert says:

    Sorry if this is slightly off topic, I am surprised that there is no mention on this website, or related ones, of http://data.giss.nasa.gov/gistemp/graphs/ showing that the global mean temperature for April set new records, and with it the January-through-April average for 2010. Isn’t this newsworthy? We have had quite high global temperatures for a while, but now we are breaking records again, aren’t we?

  8. 8
    Toppy says:

    To Gavin,

    The last prolonged La Nina episode “fully coupled” with the atmosphere was AMJ 1973 –MAM 1976: Over 30 years ago….A significant amount of warming is natural, how about we split it 50-50 (fair enough?).

    [Response: Oddly enough attribution is not done by assertion, or even fairness. But more on that another time. - gavin]

  9. 9
    Joseph Romm says:

    Uhh, Norbert, to the extent that I’m a related website, I’ve blogged at length about this record: NASA: Easily the hottest April — and hottest Jan-April — in temperature record, which notes we’ve set a new record 12-month global temperature, as predicted.

  10. 10

    #7, Norbert, it has been mentioned in comments at least. (See, for instance, here.)

    It’s also been discussed at Tamino’s blog, Open Mind, here.

  11. 11

    Oops, sorry, that last link was to the sea ice extent numbers comment instead. Try this one, rather.

  12. 12

    Another off topic- but has anyone noticed that Arthur Robinson (Man behind the so called Oregon petition) won the Rep. congressional primary in Oregon’s 4th district. Or, am I the last to know…

  13. 13
    Edward Greisch says:

    Sorry this is off topic, email from Climate 411, the Environmental Defense Fund , has alerted me to the American Power Act. Everybody should hear about this because it does not follow Jim Hansen’s formula. Information on the Act is at http://www.piie.com/publications/pb/pb10-12.pdf
    I would enact what Jim Hansen prescribed in “Storms of My Grandchildren” exactly or stronger. See:
    http://www.komanoff.net/fossil/CTC_Carbon_Tax_Model.xls The American Power Act does everything but. If the American Power Act is enacted, we would still get 16.8 quadrillion BTUs of energy from coal in 2030. That would surely continue warming the oceans. Call your senators every day.

  14. 14
    Doug Bostrom says:

    MSNBC covered this yesterday, w/coauthor Gregory Johnson. Two remarkable things about the interview: the personality handling the piece never once mentioned rejectionists and Dr. Johnson managed to twice convey to the audience an excellent thumbnail descriptor of the ocean’s role in our climate, namely that it is “the flywheel of Earth’s climate system.”

    Flywheel. That’s a marvelously intuitive yet physically reasonable way to put it.

  15. 15
    Leonard Evens says:

    On another matter:

    What, if any, effect on global temperatures 1s the Iceland volcano likely to yield?

    [Response: Given the activity to date, no detectable effect at all. First, emissions into the troposphere get washed out quickly, and second, the emissions of SO2 (which create sulphate aerosols) have been very small - some 3 orders of magnitude less than pinatubo for instance. The elements that are bad for planes are not what impacts climate, and vice versa. -gavin]

  16. 16
    Edward Greisch says:

    I am looking at the referenced indirectly http://www.nodc.noaa.gov/cgi-bin/OC5/3M_HEAT/showfig.pl
    which shows 2009 sea surface temperatures. I guess it means that most of the ocean surface temperatures are something like 3.5 degrees C warmer than before. Is that correct? That is a lot.

    [Response: Not sure where you get that from- the figure is for data distribution, not temperature. -gavin]

    I am impressed that they were able to add up the data and make the calculation. There is a mountain of data, but it seems to be rather difficult to deal with. It seems to be sort of a “fuzzy” data set.

  17. 17
    CRS says:

    Edward Greisch @ 10:14 pm, thank you for providing the link for the American Power Act. I’m very active in politics and can tell you that the forces driving the US towards further coal consumption (energy density of coal, domestic supply, labor employment, big-business/mining concerns etc.etc.) are essentially insurmountable. It drives me mad, but I’m hard-pressed to suggest alternatives.

    Imagine turning off your laptops for 23 hours/day, restricting your LCD TV and other electronic media….would any/all of you posters be so willing? We are all in this together, and yet I don’t sense any real appetite for sacrifice from Democrat (protect labor payrolls), Republican (protect industries), or otherwise.

    *sigh* the Earth will be a nice place for insects in about 50 years or so.

  18. 18
    mauri pelto says:

    Great link to the key resources. It is critical to read the Trenberth article and commentary, to fully appreciate the Ocean Warming work published and what remains to be done. It is hardly good news whether you are an ice shelf or a coral reef.

  19. 19
    bigcitylib says:

    #11, Also OT, but Robinson’s non-AGW related peculiarities have been noted here:

    http://bigcitylib.blogspot.com/2010/05/curious-mr-robinson.html

  20. 20
    NigelW says:

    In regard to heat sinks, you note that sinks of “…melting ice, are much smaller, and can be neglected in the main..”

    I would have thought that the Greenland and Antarctic ice sheets and even the 20,300 cubic kilometres of floating ice in the Arctic would have been quite significant sinks. Since 1980 the Arctic has lost almost 14,000 cubic kilometres of ice; thats warmed up to zeroC, then melted. That’s a lot of Joules gone someplace other than the atmosphere!
    http://psc.apl.washington.edu/ArcticSeaiceVolume/IceVolume.php

    Since full melt of all grounded ice is equal to over 70 metres of sea level rise, then it follows that there is the equivalent volume of 70 metres of ocean surface that is currently existing as ice at less than zero C. If your measurements of ocean heat content find most of the heating occurring in the top few hundred metres, then this equivalent volume of water-as-ice looks like an important proportion of the total ‘ocean’ sink. Yet its ‘discounted’ as able to be largely neglected?

    Its not just the melting, but the ongoing increase in ice temperature with depth that demands a lot of heat input. Are there any systematic measurements of deep ice temperatures in Greenland or Antarctica that give any indication of the actual change in energy content of all that ice, outside what is needed to crack the latent heat of freezing?

  21. 21
    Alex Harvey says:

    Gavin, I am sure many (most?) of your readers have also read the recent public exchanges between Roger Pielke Sr., Kevin Trenberth, Roy Spencer and Josh Willis. As far as I can tell, this RealClimate post today completely contradicts what Willis and Pielke both agreed, and it seems very strange to this reader that there is no mention or reference here to any of it. Do you have any comments for those readers who have seen the exchanges I refer to? Best, Alex

    [Response: Trenberth is interested in being able to say precisely where the energy flows are going on relatively short timescales - this is hard because the accuracy in the year to year numbers is not very good and so there is a lot of wiggle room. Everyone would rather this not be the case, but with the current measurement system, these year-to-year uncertainties will persist for a while longer. Over the longer term the accuracy is better, there is less wiggle room, and in fact we are able to balance out the energy flows - i.e. the increase in ocean heat content is pretty much what is expected from the anticipated radiative imbalance (see the figure). Perhaps you could be more precise about what you think is contradictory? - gavin]

  22. 22
    dhogaza says:

    Still OT but … Dan Satterfield …

    Another off topic- but has anyone noticed that Arthur Robinson (Man behind the so called Oregon petition) won the Rep. congressional primary in Oregon’s 4th district. Or, am I the last to know…

    DeFazio’s seat is not at risk. The Republicans will focus on the 1st and 5th district.

  23. 23
    Marcus says:

    Pielke Sr. posted on this: http://pielkeclimatesci.wordpress.com/2010/05/21/update-on-jim-hansens-forecast-of-the-global-radiative-imbalance-as-diagnosed-by-the-upper-ocean-heat-content-change/ – but of course, can’t just come straight out and admit that he was flat out wrong (http://pielkeclimatesci.wordpress.com/2009/02/09/update-on-a-comparison-of-upper-ocean-heat-content-changes-with-the-giss-model-predictions/) and that models and ocean heat content match but rather, now we have to wait a few years to know if models are correct.

  24. 24
    Edward Greisch says:

    16 response: Oh. Those are number of data points per some area? Then why are the white areas not black and where are the temperatures? How much warmer is the ocean surface? I will look harder. Thanks. Better go back to
    http://www.nodc.noaa.gov/cgi-bin/OC5/3M_HEAT/showfigheat.pl?action=start

    17 CRS: There is no reason to go without electricity. Again read “Storms of My Grandchildren.” I agree with Dr. Hansen and President Obama that we have unlimited safe clean cheap nuclear power available as well as large amounts of wind, solar and geothermal depending on geography. The only real problems are the $100 Billion cashflow of the coal industry, the $1 Trillion cashflow of the total fossil fuel industry and people who object to nuclear for reasons unknown to me. Please, I am not trying to start another interminable debate. Please argue with Hansen and Obama on nuclear. Both industry [except the fossil fuel industry] and labor can easily be protected and benefitted by a change in energy source. The economy as a whole can grow because of the changes in energy sources. The fossil fuel stockholders would be better off to sell out sooner rather than later, but they refuse. It is CO2, not energy use that we are fighting. The American Power Bill shows that we have made progress. Keep calling your senators.

  25. 25
    Blair Dowden says:

    The units used to measure heat content on the graph are in 10^22 Joules. It would be helpful if this could be converted to more familiar units, such as watts per square meter required to generated this much heat, or the number of degrees Celsius this will raise the water temperature.

    By the way, I am pleased to see two science postings in a row!

  26. 26
    Mike says:

    “(Other reservoirs for this energy, like the land surface or melting ice, are much smaller, and can be neglected for the most part).”

    OK, I’m no expert so this may be a trivial question. Could the ocean floor absorb a non-negligible amount of heat?

  27. 27
    SecularAnimist says:

    gavin wrote: “… this is more evidence that the planet is basically behaving as the scientists think it is. And that isn’t necessarily good news.”

    With the greatest of respect, that sort of understated, scientifically detached and dispassionate discourse is not helpful.

    The “news” is extremely, shockingly, horrifyingly BAD.

  28. 28
    Ike Solem says:

    Obviously the deep ocean >700 meters is the most difficult place to sample temperature changes (and to drill for oil). If you have good measurements of upper ocean and atmospheric temperatures, then if you had a good decade-long satellite record of the Earth’s total radiative energy balance from space – say, if Triana has been launched to in the late 1990s – then you could use conservation of energy to calculate the rate of heat uptake by the deep ocean over the past ten years. Since this satellite wasn’t launched – the fossil fuel lobby managed to block funding for Triana with some political assistance – you’d instead have to rely on the stitched-together records of near-Earth satellites.

    Even so, many of the difficulties involved in processing existing satellite data have been resolved, for example:

    http://ruby.fgcu.edu/courses/twimberley/EnviroPhilo/Fu.pdf

    Fu et al. Enhanced Mid-Latitude Tropospheric Warming in Satellite Measurements, Science 2006

    The spatial distribution of tropospheric and stratospheric temperature trends for 1979 to 2005 was examined, based on radiances from satellite-borne microwave sounding units that were processed with state-of-the-art retrieval algorithms. We found that relative to the global-mean trends of the respective layers, both hemispheres have experienced enhanced tropospheric warming and stratospheric cooling in the 15 to 45° latitude belt, which is a pattern indicative of a widening of the tropical circulation and a poleward shift of the tropospheric jet streams and their associated subtropical dry zones. This distinctive spatial pattern in the trends appears to be a robust feature of this 27-year record.

    This is in direct contrast to the previous claims of media skeptics like Sallie Baliunas (July 2005)

    Simulations of the enhanced greenhouse effect forecast a warming trend of approximately 0.25 to 0.35º C per decade, or accelerated warming compared to the surface. The well-validated temperature of the low troposphere shows a significantly smaller trend, +0.077º C per decade.

    In fact, Fu et al. report tropospheric mean rates of +0.20 K per decade, as well as stratospheric cooling of -0.33K per decade, well within the ranges predicted by global climate models forced with fossil fuel emissions and ozone changes.

    Sallie Baliunas was so surprised by this result that she threw in the towel and declared that the skeptic’s argument no longer holds much weight. Furthermore, she said, “In 1999 we pointed out that, quote, ‘When tested against the Arctic temperature record… the computer forecasts are seen to exaggerate the projected warming by a large amount.’ Obviously, we were wrong about that, too. Rational scientists can no longer support that position.”

    Really!

  29. 29
    Hank Roberts says:

    Marcus, that was a good summary with pointers, thank you.

  30. 30
    RichardC says:

    Denier sites use the NODC OHC data as it shows a mini-trend of cooling. Why is Lyman et al more accurate?

  31. 31
    Frank Giger says:

    Mr. Dowden, I think I have the conversion from Joules to degrees Celcius for the scale, but corrections to my math are very welcome for my hasty calculations.

    My approach was to convert joules into calories and then apply that to the volume of the ocean.

    I converted the measureable scale span into calories.
    Then Cubic area of oceans (cubic KM) to milliliters.
    Finally, milliliters divided by calories.

    The numbers worked out like this:

    2×10(23) (measurable scale) x 4.184 (calories per Joule, which is also what is required to raise 1 ml of water one degree celcius) = 8.37×10(23) calories.
    1.33×10(9) cubic KM volume of oceans = 1.33×10(24) liters (gotta love the way metrics is synched for measurements)

    1.33×10(24) milliliters of ocean water divided by 8.37×10(23) (total calories) = 1.59 degrees celcius for the entire measureable scale.

    Loads of problems with my calculation – let’s consider it a rough thumbnail. First, the study measured the top 700 meters, so using the entire volume could make the whole thing hopelessly wrong. Second, I relied on the good old Internet for ocean volume, so that might be wrong, invalidating it. And third, I’m a bit rusty and might have used some Jethro Clampett “Cyphering” on the math.

    At any rate, the big thing is that there is a helluvalot of energy getting absorbed into the ocean.

  32. 32
    Len Ornstein says:

    Gavin:

    Can freshening of the polar oceans have sufficiently increased (but been inadequately measured) so that down welling is reduced, and therefore the deep ocean is hiding a pause in its warming?

    The best estimates of sea level rise would be insensitive to such a change – except for the very small non-linearity of the density of sea water with temperature. And that might account for the small anomaly between SLR and upper ocean heat content for the last decade?

  33. 33
    Patrick 027 says:

    Re Toppy – assuming the equilibrium climate (as measured by global average surface temperature) doesn’t shift with ENSO, a La Nina should actually cause a gain in heat. My understanding is that ENSO changes the global average surface temperature by vertically rearranging the heat in the ocean. By exposing colder water over a larger area of the surface, a La Nina would cause a radiative imbalance that leads to some heat gain. An El Nino would have the opposite effect. The positive feedbacks reduce the imbalance in that case, but they would prolong the time it would take for the global average surface temperature to return to equilibrium if the La Nina or El Nino were permanent.

  34. 34
    Paul K2 says:

    Blair Dowden, I am not a climate expert, but here is my read of these papers regarding your question of how 10^22 J/yr compares using other measurement units:

    Please read both the paper and Dr. Trenberth’s commentary in the same issue of Nature; then go read this Trenberth paper (which Gavin also linked). Trenberth uses a pretty good comparison to heat released by burning fossil fuels: “Human activities contribute directly to local warming through burning of fossil fuels, thereby adding heat, estimated globally to be about 4 x

  35. 35
    Paul K2 says:

    Most of my previous comment didn’t post properly…

    Trenberth’s paper says: “Human activities contribute directly to local warming through the burning of fossil fuels, thereby adding heat, estimated globally to be about 4 x 10^20 J/yr …” So the unit of 10^22 J/yr is about 25 times all the heat released from fossil fuel combustion.

    In the Lyman et. al. paper, they say:

    “Accounting for multiple sources of uncertainty, a composite of several OHCA curves using different XBT bias corrections still yields a statistically significant linear warming trend for 1993–2008 of 0.64 W m-2 (calculated for the Earth’s entire surface area), with a 90-per-cent confidence interval of 0.53–0.75 W m-2.”

    Given the trend in OHC from the Lyman graph is slightly less than 1 X 10^22 J/yr, then we can compare the yearly trend of 0.64 W m-2 to get an idea how OHC compares to the planetary energy budget.

    I find that Trenberth’s commentary is necessary to understand the Lyman et. al. results in comparison with other data. Trenberth shows (Figure 1) a quick and dirty comparison of the Lyman trend versus the data from a previous study of Argo data down to 2000 m, instead of the 750 m data used in Lyman. This data from Argo from a fairly short period of 2003 to 2008, shows a trend of 0.54 W m-2. Here is Trenberth’s comment:

    “The warming ocean is revealed by changes in heat content from 1993 to 2008, shown by the black line with error bars, as constructed by Lyman et al.1. This analysis samples the ocean to 700 m depth and gives an average warming trend of 0.64 W m−2 (red line). The data available from Argo floats since 2003 enable an estimate to 2,000 m depth (blue line)8 to be made. The differences between the black and blue plots after 2003 suggest that there has been significant warming below 700 m, and that rates of warming have slowed in recent years. Processing of the two data sets is not compatible, however, so firm conclusions cannot yet be drawn by comparing them.”

    This seems to show that a significant amount of heat is ending up in the deeper ocean.

    Another issue that seems to be problematic; the recent flattening in OHC seems inconsistent with SLR, which currently is close to the long term trend. I don’t think that increased ice sheet melt can explain the difference.

    It will be interesting to see if the Argo data show areas where significant amounts of heated water is being pushed down into the ocean. Perhaps the delivery of heated water into the deeper ocean is spatially distributed in a highly irregular pattern. Clearly we don’t have enough information on how heat is being absorbed into the ocean heat sink.

    I hope I have interpreted these papers correctly.

  36. 36
    RichardC says:

    33 Patrick said, “By exposing colder water over a larger area of the surface, a La Nina would cause a radiative imbalance that leads to some heat gain.”

    So a La Nina warms the planet and an El Nino cools the planet even though we think of them the opposite way.

  37. 37
    CRS says:

    24 Edward: Thanks for the conversation!
    [edit - OT]

    And, just try to take coal away from politicians of any stripe from a producing state!! Illinois is having a coal renaissance, our high-sulfur coal is cheap and popular….utilities can scrub the sulfur out of the off-gas for less money than higher-cost Wyoming low-sulfur coal. The Democratic party is in lock-step with union forces, and won’t be turned back.

    *sigh* It will be easier to deal with the chemical and geoengineering aspects of carbon mitigation (I’ve done this work under the Kyoto CDM) than with the political forces!! Don’t forget, even if the USA halted all coal consumption, we would have to deal with China and India etc. It is damn frustrating, I share Dr. Hansen’s feelings.

    I feel like I want to write a sequel book “Arthropod Plagues of our Grandchildren.” At least insects are high in protein….

  38. 38
    Mesa says:

    Trenberth’s article is a good example of an honest assessment of the state of climate science, and the limitations of the data and our understanding thereof. It doesn’t alter the Bayesian prior that increased CO2 is likely to cause warming to be upfront about the limitations of our understanding or of our data gathering status. It is the opposite of what we have come to understand about other segments of the climate science culture, both in its honesty and realization that humans will adapt whatever actually transpires.

  39. 39
    Brian Dodge says:

    There is no mention in the paper of latent heat from the melting of Arctic sea ice.

    Cheers, Alastair McDonald — 21 May 2010 @ 6:06 PM

    [Response: No. Work out the numbers. - gavin]

    Ask and ye shall receive. Also to NigelW — 22 May 2010 @ 6:21 AM

    1 joule = 1 watt second
    5.1e+14 earth area m^2
    240 watts/m^2 surface insolation
    1.224e+17 joules/second
    31557600 sec/year
    3.86265024e+24 joules per year

    334000 joules to melt 1kg of ice

    500 km^3 Greenland loss 220 cubic kilometers in 2005. http://www.nasa.gov/vision/earth/lookingatearth/greenland-20060216.html
    100 km^3 loss Antarctica http://www.nasa.gov/topics/earth/features/20100108_Is_Antarctica_Melting.html
    500 km^3 loss other glaciers SWAG, Scientific Wild Ass Guess. According to http://www.grid.unep.ch/glaciers/img/tab3-1.jpg, the area of glaciers + ice caps excluding greenland and Antarctica is less than 1/3 that of Greenland, so this is very likely a high estimate
    1100 km^3/year total
    1.1e+12 m^3/year
    917 kg/m^3 for ice
    1.0087e+15 kg/year
    3.369058e+20 joules
    0.0087 percent going into permanent ice melt, which shows up in sea level rise.( NB, warming of the oceans also causes sea level rise through thermal expansion

    9000000 km^2 Arctic sea ice melt spring – summer
    1.8e+13 m^3 at a 2m average thickness – this is generous – see http://psc.apl.washington.edu/ArcticSeaiceVolume/IceVolume.php
    917 kg/m^3 for ice
    1.6506e+16 kg/year
    5.513004e+21 joules
    0.143 percent going into ice melt spring – summer; BUT, a roughly equal amount comes back out during the refreeze in the fall – winter; and since it’s floating, it doesn’t effect sea level.

    BTW, I have been known to miscount decimal places, so I wouldn’t bet a large amount that these numbers aren’t off by a factor of ten – YMMV, and one[Alistair & Nigel] would learn a lot by checking these estimates with other numbers – e.g. the TOA insolation is ~344 W/m^2; starting there, do my numbers still make sense? If you Google the best estimates of runoff +thermal expansion contributions to sea level, and assume that the none thermal expansion part came from permanent ice melt, do you get similar volume numbers?

  40. 40
    Rod B says:

    Gavin (8), then you’ll have to explain your poor results to the Affirmative Action people!

  41. 41
    TRY says:

    “Oddly enough attribution is not done by assertion, or even fairness. But more on that another time. – gavin”

    But computer models are entirely built on assertions, no? You may argue that those assertions are justified, but the model itself is not the actual system.

    The post says “if there has been more energy coming in at the top than is leaving, then it has to have been going somewhere “. And another comment of yours says: “the increase in ocean heat content is pretty much what is expected from the anticipated radiative imbalance “.

    Both implying that there has been no actual measurement of the actual radiative imbalance. I had a long discussion on this forum several months ago regarding the ability to directly measure radiative imbalance from outside the atmosphere, and no one seemed particularly interested in it. Any papers on this that you could point to?

  42. 42
    Mike G says:

    What sort of temperature rise in deep ocean basins would be sufficient to destabilise clathrates? Does anyone know?

  43. 43
    Doug Bostrom says:

    What sort of temperature rise in deep ocean basins would be sufficient to destabilise clathrates? Does anyone know?

    I wish I could remember where I read it, but I seem to remember that the margins of methane clathrate deposits are more or less at equilibrium w/regard to their response to temperature and pressure which of course completely figures. That being the case, I suppose any change in temperature or pressure conditions will cause a change in the location of the margins. Presumably a larger change will cause a larger movement of margins and a more rapid change will trigger a more rapid movement of clathrate margins.

    Sort of the same deal with ice; it’s automatically adjusted to prevalent conditions and hence quite sensitive to changes.

  44. 44
    Leonard Evens says:

    Re: 38: says
    “Trenberth’s article is a good example of an honest assessment of the state of climate science, and the limitations of the data and our understanding thereof”

    and then goes on also to say

    “It is the opposite of what we have come to understand about other segments of the climate science culture, both in its honesty and realization that humans will adapt whatever actually transpires.”

    Well, we can all read into Trenberth what we wish, but let me quote what he actually says.

    “Given that global warming is unequivocally happening
    [12] 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.
    We will of course adapt to climate change. The question
    is the extent to which the adaptation is planned and
    orderly with minimal disruption and loss of life, or
    whether it is unplanned?”

    It seems to me that Trenberth is not particularly more sanguine than “other segments” about the prospects. That conclusion is based not just on this article but also on other things he has written.

    In any case, the article is not at all about just how alarmed we should be. It is rather a call for resolving uncertainties to help us better cope with climate change.

  45. 45
    David B. Benson says:

    Mike G (40) — You can find the phase diagrams of pressure versus temperature for clathrae stability and compare those to temperatures at various depths. Somewhere there is a graphic of that. Briefly, the only (moderately substantial) clathrate dissolutions are in/near the Arctic Ocean at shallow depths. The vast majority of the methane released remains in the ocean.

    Of greater conern are the resevoirs of methane in wetlands and permafrost.

  46. 46
    Norbert says:

    #9 – #11: OK, I’m glad it wasn’t a secret anymore. :) However 1 blog post and a few comments by Kevin himself here and there isn’t a lot of coverage. Probably most here take it for granted that temps are rising. It seems that only a complete record year, with a confirming result from CRU, would count.

    Looking at the (Gistemp) graphs, as a non-expert, it doesn’t seem that records can easily be broken by “weather” alone, and recently we are consistently close to record temps. Perhaps not enough to convince those who believe everything is a result of urban and arctic heat islands, but I think enough of a signal to send to those who are not following the graphs by habit, but occasionally stop by, trying to find out what the facts are.

    Back to topic, or at least closer:

    Apparently, in the years around 2001-2002, there was a very steep increase of ocean heat as measured. The time span after 2003 doesn’t seem that unusual if one considers the possibility that the high values around 2003, and the low values shortly before the 2001-2002 period, have been “weather” rather than “climate” and are obscuring the underlying continued upward trend.

    Again, (speaking as someone occasionally stopping by), these articles highlight that the quality of the models are not the bottleneck of research, but the acquisition of measurement data. Which, in turn, I would guess, is mostly a question of financial resources. However, it doesn’t seem that climate research is already consuming huge amounts of resources, so I wonder whether the resources are not increasing as one would expect, or whether this is just not being discussed in public, or whether I just missed it due to the specific limited reading I do.

    I read somewhere that NASA recently was able to start using 2 drones for atmospheric measurements. But what about increasing the number of arctic measurement stations, as apparently the mismatch between NASA and CRU results indicates a lack of data here, and what about the question of whether the uncertainties in this article about ocean heating could be resolved by improving resources. (BTW, what about measuring the temperature of the ice, rather than just whether it melts or not, don’t know if that makes sense).

    The authors obviously wish for better measurement data, but it doesn’t become clear (to someone like me) whether technically solutions are ready to improve the situation, if financial resources were available, and whether any financial investment could be expected to be spent well in technically effective ways. I’m sure these questions are discussed elsewhere, but it doesn’t become clear to me here in this context.

  47. 47
    NigelW says:

    Thanks Brian Dodge 39! Useful reassurance. The only bit you appear to ignore is the heating of the ice up to zero. But since the latent heat requirement is a lot more than the warming requirement, it is likely is it not that that figure would be similarly low % of the global insolation. Thanks again; I’ll pull that one worry bead off my necklace! N

  48. 48
    RiHo08 says:

    If the measured Global Sea Surface Temperatures as measure by AMSR-E since 2003 vary between +2 C and – 2.5 C, and the trend has demonstrated a slight decline, whom should we believe? The models which report a continuing increase? Lyman et al 2010 who adjust the raw data for an extrapolated result? or consider a pie-in-the sky speculation that the “missing” heat now resides in deeper and as yet unmeasured oceans? This article cries out for an editor to say “show me the beef.” The article has none, just mouthing words. Sad, sad sad.

    [Response: What's sad is the continual jumping from one source of data to another, from one start date to another and for ever less significant time-periods in a desperate attempt to demonstrate to yourself that the planet is not warming. It is. Get used to it. - gavin]

  49. 49
    Frank Giger says:

    Mr. Benson, where can I find a frostline/treeline map, and if there’s been a measureable change in them.

    To be honest, its something I’ve been waiting to read about. If the tundra is slowly giving way to the boreal forest it will be the “in your face” sort of symptom of global warming that is far more convincing than a weather event.

    Oh, and did anyone check my math in the scale conversion? I’m gonna relook it, as I think I may have misplaced a decimal point. 1.6 degrees celcius seems to be too large for the range of temperature increase.

  50. 50
    Mal Adapted says:

    Ike Solem @28:

    Sallie Baliunas was so surprised by this result that she threw in the towel and declared that the skeptic’s argument no longer holds much weight.

    Ike, that’s fantastic news! Can you provide a cite? I could have used it in a recent face-off with a couple of D-K-afflicted parties.


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