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  1. The solar energy will increase in the next 10 years, progressing to solar maximum. The chance to get an El Nino is also considerable high. This means that there will be very likely a new temperature record we can expect. At the same time the cryosphere response progresses to a more ice free state. Which further accelerates feedbacks.

    The problem is that we cannot just stop these processes, because of the big inertia of the climate system. That is why we need to fix the CO2 problem today, not when extremes disrupt society to a degree which makes actions harder and the chance to pass other tipping points. Hansen further explained how a +2C target is analog to the early Pliocene, which comes with 15-25 higher sea levels. We are now roughly at +1C.

    The media has to report this properly, with input from scientist – to accurately message the science to the public! We threaten the habitability of what we call home if we continue with inaction, if we continue with burning of fossil fuels!

    Comment by prokaryotes — 25 Sep 2013 @ 4:07 AM

  2. Thanks for this very helpful post. I have a question about one of your calculations.

    “The increase in the amount of heat in the oceans amounts to 17 x 10^22 Joules over the last 30 years. That is so much energy it is equivalent to exploding a Hiroshima bomb every second in the ocean for thirty years.”

    Am I right in thinking that a Hiroshima bomb is approx 67TJ of energy (or 67 x 10^12J)? That seems to be an often-quoted figure. If so, then 67TJ per second for 30 years is 67 x 60 x 60 x 24 x 365.24 x 30 = 63,429,039,360 TJ = ~6.3 x 10^22J.

    This is only roughly a third of the 17 x 10^22J figure quoted in the text. So am I wrong in thinking that it would be more accurate to speak of approximately *three* Hiroshima bombs per second of extra energy being added to the oceans over the last thirty years? (Or ~2.68 bombs per second to be more accurate)

    Comment by Byron Smith — 25 Sep 2013 @ 5:15 AM

  3. Thanks for another great article. Near the end, you note:

    “The data hole in the Arctic that explains part of the reduced warming trend (maybe even more than previously thought).”

    This links to an article in German. I think I could make out the gist of it, but perhaps you could give your synopsis. Is there a lot more warming of the Arctic Ocean than was previously thought? How large of a role has ocean warming been playing in the rapid loss of sea ice volume there?

    Thanks again for the article, and thank ahead of time for any further light you can through on the (now quickly darkening) Arctic.

    Comment by wili — 25 Sep 2013 @ 5:43 AM

  4. As we have typically expressed energy in the atmosphere on a degrees C scale, I thought this might be useful from the UK Met Office, for context.

    Met Office: What do observations of the climate system tell us? – July 13

    “…Careful processing of the available deep ocean records shows that the heat content:of the upper 2,000m increased by 24 x 1022J over the 1955–2010 period (Levitus, 2012),equivalent to 0.09°C warming of this layer. To put this into context, if the same energy had warmed the lower 10km of the atmosphere, it would have warmed by 36°C! While this will not happen, it does illustrate the importance of the ocean as a heat store. ”

    finding a rate <2oooths of a degree C per decade.
    (ref increase in 0.09C in 55 years) is that really measurable?
    ie one ARGO buoy per how many thousand cubic kilometres of ocean. (and we've only had ARGO, for a decade, or less at depth)

    [Response: Changing a unit to have a small sounding number doesn’t actually change anything; neither the significance nor the accuracy. But if you want to play rhetorical games, go right ahead – though perhaps not here. – gavin]

    Comment by Barry Woods — 25 Sep 2013 @ 6:00 AM

  5. Whoops, missing the huge 1982/83 El Niño… Shows up in the original versions of the figure.

    [Response: Odd. I have updated the figure to the current version taken directly from the Climate Central website which does include 82/83. Sorry about that. – gavin]

    [Response: Thanks Gavin. Climate Central made me a Celsius version at short notice (for German readers), thanks to them for doing that, but a slip-up must have occurred. So back to Fahrenheit. 82/83 is a case in point of course. – stefan]

    Comment by Kelly H — 25 Sep 2013 @ 8:41 AM

  6. Thanks you for this. My executive summary is that the ocean as a whole is continuing to heat up at a constant rate, which suggests that heat being retained by the greenhouse effect has also been increasing at the same rate for the past 30 years. Some heat is being transferred to the deeper ocean by wind changes, reducing the rate of increase in the upper layer, which reduces the warming rate on land. As for changes in the solar cycle, is the following sentence correct? “The transition from solar maximum to solar minimum probably also contributed a small part as planetary heat absorption decreased by about 15%.” I assume you mean the change in the annual increase, rather than total planetary heat absorption.

    Comment by Blair Dowden — 25 Sep 2013 @ 8:42 AM

  7. Thanks for this post Stefan. It is very timely given the “pause” the denialosphere is so intent on focusing on.

    Comment by tokodave — 25 Sep 2013 @ 8:43 AM

  8. re: prokaryotes @ 25 Sep 2013 at 4:07 AM


    We are at solar max now and we have been a while without an El Nino.

    Comment by James Cross — 25 Sep 2013 @ 8:58 AM

  9. Here is the link to the Met Office report that I quoted, for context


    Comment by Barry Woods — 25 Sep 2013 @ 9:08 AM

  10. This is a very timely article, given all the recent nonsense about no temperature increases in the last decade. The first graph shows how meaningless this claim is.

    However, I have a question about the use of the word “heat.” I’m sure that just about all climate scientists know the definition of the word, but, as in this article, I often see it used incorrectly. Talking about heat as contained somewhere makes it seem as if the discredited “caloric theory” is still the basis of thermodynamics. Since heat is now defined as “the transfer of energy between two systems as a result of a temperature difference,” heat itself is not a substance that can be stored. Energy is stored, the transfer of energy is not.

    Isn’t it time to use the interest in climate science to educate the public on the correct meaning of heat?

    [Response: I think you are pushing uphill on this. Heat has so many common meanings and connotations, that changing its use in popular writing is probably impossible. That, plus the observation that there is no actually ambiguity or confusion in what is being communicated, makes the point somewhat technical and even arcane. So good luck with that. – gavin]

    Comment by Bob Reiland — 25 Sep 2013 @ 9:16 AM

  11. Could someone translate 10^23 joules into degrees, for those of us afraid to slip a digit figuring the volume of the ocean?


    [Response: 10^23 J in the ocean = 2.8 x 10^8 J/m2 = 1.4 x 10^5 J/m2 over 2000 m depth ~= 1.4 x 10^2 J/kg ~= 0.04ºC (averaged over the whole depth). Much bigger changes are near the top though. – gavin]

    Comment by Downpuppy — 25 Sep 2013 @ 9:18 AM

  12. I think it is inaccurate to say “deeper than that(2000m) not much happens”. If you mean not much observing happens you are right. If you mean changes in ocean temperature, Purkey & Johnson 2010 have looked at that.

    Comment by Krishna AchutaRao — 25 Sep 2013 @ 9:42 AM

  13. Thanks James for pointing that out, took me a moment to find the current data on this.

    Comment by prokaryotes — 25 Sep 2013 @ 9:42 AM

  14. Bob (#10)

    It is still popular nomenclature in physical oceanography and atmospheric dynamics to refer to the bodily transport of energy by a fluid as “heat transport.” Technically, heat is a quantity of exchange, not a property of the fluid, and the “transport” we speak of differs from heat fluxes (e.g., radiation)…see Warren, 1999 (JGR) for a more thorough examination of the terminology. Generally “enthalpy” is what is actually meant. But I agree with Gavin that this is not very important in the public discourse, and probably not even in the scientific literature. I don’t know of much confusion on what is being talked about that has stemmed from this.

    Comment by Chris Colose — 25 Sep 2013 @ 10:12 AM

  15. Re solar cycle

    Because of the variations of sunspots and faculae on the sun’s surface, the total solar irradiance (TSI), also called the solar constant, varies on a roughly 11-year cycle by about 0.07%, which has been measured by orbiting satellites since 1978 [Lean, 1987, 1991; Wilson et al., 1981]. The change in the solar constant amounts to about 0.90 Wm2 for the last three cycles. 2007 study

    Comment by prokaryotes — 25 Sep 2013 @ 10:36 AM

  16. Wili @3: Load Stefan’s German-language post into Google Chrome. Chrome will ask if you want a translation. The translation isn’t perfect, but the main messages are there. In deutscher oder englischer Sprache, ist Stefan ein erstklassiges Klima Kommunikator.

    Comment by Jay Dee Are — 25 Sep 2013 @ 10:44 AM

  17. With the Kosaka and Xie paper gaining some prominence, I am seeing a few of the simple 2-box models apply the Southern Oscillation Index (SOI) as a noise compensation to get a better fit to the global temperature records. Some terrific looking model fits include the following:

    These are taken from this recent discussion at SkS:

    My question is: Is it getting close to when the SOI can be used to automatically remove the pseudo-oscillatory ocean noise? The SOI signal is stationary over decades as it shows very little trend.
    Another way to put it: how much residual noise would the GISS, HadCRUT, etc data sets have after compensating via the SOI record?

    Comment by WebHubTelescope — 25 Sep 2013 @ 11:19 AM

  18. @ stefan

    Nice article. I am very interested in this subject and I am also learning German at the moment (since I am now working in Vienna). Are there any good websites like Real Climate that are only in German? I think one learns best when they read stuff that is interesting.

    Comment by Colin Johnstone — 25 Sep 2013 @ 11:26 AM

  19. > prokaryotes … The solar energy will increase
    > in the next 10 years, progressing to solar maximum …

    Check before repeating that belief. You appear to predict Cycle 25 will peak in 2023, higher than Cycle 24 peaking this year. It’s possible. It’s interesting. But is this your own prediction? something you read somewhere? Why think so?

    The sensitivity of the energy budget and hydrological cycle to CO2 and solar forcing
    Earth Syst. Dynam. Discuss., 4, 393-428, 2013

    Comment by Hank Roberts — 25 Sep 2013 @ 11:27 AM

  20. I’m with Bob [10] — in spirit, anyway — on “heat.” Better term for this use would be thermal energy, but understand the need not to be too pedantic.

    However… proper use of the term could help, in the present discussion. We have energy being transferred into the system via the greenhouse effect (moving from electromagnetic to thermal), and then we have energy transferred from atmosphere to ocean via First Law — i.e., “heat.”

    Comment by robert — 25 Sep 2013 @ 12:15 PM

  21. Regarding the “pause” in surface warming. I’m not hearing much about aerosol screening as a result of massive buildup of coal-fired power plants in China and India. Given the significant role such aerosols played in the 40’s, 50’s, 60’s from U.S. and European emissions (prior to serious scrubbers), and that the scale in China / India right now is significantly larger, why wouldn’t this aerosol screening (global dimming) be an issue?

    [Response: Indeed. I think this should very much be part of the discussion. There is a lot of evidence that Chinese aerosols are underestimated in the CMIP5 models and in the emission data sets. We don’t yet have a good estimate of what this underestimate implies – though people are working on it. – gavin]

    Comment by robert — 25 Sep 2013 @ 12:18 PM

  22. Hank Roberts

    Why think so?

    If you google solar cycle all the images you get show solar minimum. If you go to wikipedia same, though i just fixed that.

    Comment by prokaryotes — 25 Sep 2013 @ 12:21 PM

  23. Nice and informative article, thanks!

    I have one question. In the section on links with ENSO, you write that the recent reduced warming rate of the upper 700m is related to natural variability, given the clustering of La Niñas in the last fifteen years. A valid point indeed, but are you confident that this is ‘natural variability’? Might it be speculated that a change in ENSO (more frequent La Niñas) is an aspect of global warming, rather than natural variability? I realize of course that this is conjecture, and other explanations such as e.g. stochastic behavior or modulation by other modes of variability are perhaps more likely to be correct.

    [Response: Good question, but one that’s hard to answer. It’s possible, but it may also be that it would take a really long time to demonstrate it clearly because of the variability. In the absence of that demonstration, it’s probably best to assume only a small or negligible effect. – gavin]

    Comment by Arne Melsom — 25 Sep 2013 @ 1:35 PM

  24. Stefan, I linked above to one comparison of CO2 vs. solar forcings (Schaller et al., doi:10.5194/esdd-4-393-2013).

    Their abstract says “energy budget calculations show that poleward atmospheric energy transport increases more in solar forcing compared to equivalent CO2 forcing simulations, which is in line with the identified strong increase in large-scale precipitation in solar forcing scenarios.”

    That sounds like the effect may come not from direct heating, but from rearranging wind patterns and precipitation (and perhaps changing ocean temperature structure?)

    You point out in the main article that “the cold sun is not noticeably slowing global warming” pointing to the Guardian’s article and the graphic from Feulner & Rahmstorf (2010).

    Here (Krivova and Solanki) say their “… models of solar irradiance variation … progress over the last half decade …. For the period after 1974, … there is no evidence for any non-magnetic change in the solar irradiance on time scales longer than about a day.”

    Solanki’s earlier work was popular with the “It’s the Sun” crowd, but if I read that right, they’re saying variation of the Sun’s direct forcing is trivial, and those older studies were making too much of tiny changes.

    (I realize solar over time averages out to no trend, while CO2 forcing is steadily trending upward — I wonder if varying insolation changes wind patterns and intensities, to change ocean temperature/depth arrangement (and plankton blooms and clouds and albedo change as that happens).

    Comment by Hank Roberts — 25 Sep 2013 @ 1:37 PM

  25. How do you explain the regional investigations: The UOHC ( 0…700m) of the northern extratropics: where we can see a decline after about 2005 and the southern extratropics:–19N_n.png where we find a strong increase of the UOHC? Is the heat on the road to the abyss only in the NH? What kind of “downward elevator” is working only in NH?

    Comment by Frank — 25 Sep 2013 @ 1:43 PM

  26. Gavin or Stefan – The cited data suggest that the rate at which the Earth has been storing energy recently does not greatly exceed 0.30 W/m^2. Other OHC estimates have suggested a larger quantity. How are these data reconciled with estimates of the planetary energy imbalance from a variety of model sources that are closer to 1.0 w/m^2? This is of particular interest in relation to “effective climate sensitivity” estimates that rely heavily on OHC uptake data.

    Comment by Fred Moolten — 25 Sep 2013 @ 2:20 PM

  27. Seconding Krishna AchutaRao at 25 Sep 2013 9:42 AM. Observations are sparse but still enough to yield statistically significant insights, pretty much all of which are disturbingly consistent with what’s going on up here in the daylight. To paraphrase the late Senator Dirksen, a few Sverdrups here and a Sverdrups there and pretty soon you’re talking more than small change. Follow Johnson et al into the depths!

    Comment by Doug Bostrom — 25 Sep 2013 @ 2:49 PM

  28. Does this result allow you to get a meaningful estimate of the radiative imbalance of the earth? Doing a simple calculation from the first figure:

    From 1985 to 2012 (28 years) the heat content increased by 2×10^23J. That time is 28*365*86400s=8.83×10^8s. This gives a power of 2.2×10^14W~=0.45W/m2

    If this is 90% of the heating of the earth we would get around 0.5W/m2.

    Is this at the lower end of estimates? A fairly recent paper by Trenberth&Fasullo (Surv Geophys (2012) 33:413–426) quotes an estimate of 0.9W/m2 (+-0.4W/m2 if I remember correctly).

    Comment by Thomas Huld — 25 Sep 2013 @ 3:04 PM

  29. Krishna AchutaRao above suggested Purkey & Johnson 2010
    Thank you!

    Looking their work up in Scholar finds among much else worth reading

    A review of global ocean temperature observations: Implications for ocean heat content estimates and climate change

    J. P. Abraham1,*, M. Baringer2, N. L. Bindoff3,4,5, T. Boyer6, L. J. Cheng7, J. A. Church4, J. L. Conroy8, C. M. Domingues5, J. T. Fasullo9, J. Gilson10, G. Goni2, S. A. Good11, J. M. Gorman1, V. Gouretski12, M. Ishii13, G. C. Johnson14, S. Kizu15, J. M. Lyman14,16, A. M. Macdonald17, W. J. Minkowycz18, S. E. Moffitt19,20, M. D. Palmer11, A. R. Piola21, F. Reseghetti22, K. Schuckmann23, K. E. Trenberth9, I. Velicogna24,25, J. K. Willis25
    online: 23 SEP 2013

    DOI: 10.1002/rog.20022

    Comment by Hank Roberts — 25 Sep 2013 @ 3:52 PM

  30. Where are the paleo reconstructions for deep ocean temperatures? Seems that’s missing at the Wikipedia link.

    Comment by Ed Barbar — 25 Sep 2013 @ 4:24 PM

  31. This is the most helpful article that I’ve read on the topic, demonstrating multiple lines of evidence. I think the part about differential warming of different layers of the ocean to be particularly clear and useful.

    Comment by Rob Nicholls — 25 Sep 2013 @ 4:33 PM

  32. I’m still sitting here stunned by the 17⨯10²² Joules in 30 years figure. Coupled with the “atmosphere stores only about 2%”, I figure this works out to 163,200 quads of energy in 30 years. Or about 5440 quads per year. In 2010, all humans production and use of energy amounted to 524 quads. (Some 85% of which is a number I remember being associated with fossil fuel sources.)

    Which implies that the mere average watts from global warming going back over the last 30 years is perhaps more than 10 times higher than the average watts from human productive use in the latest year of 2012.

    Global warming effects are accumulating, which gives great power to their results over time. While human production and use is year by year. But what a huge leverage factor that implies.

    Comment by Jon Kirwan — 25 Sep 2013 @ 5:30 PM

  33. hello, thank you for your article. i got the gist of it, even though i’m not a scientist and don’t understand all the detail. i have been interested to find out lately how the gulf stream is going? With this increase in ocean temperatures,has it almost stopped yet? the weather seems to be becoming more extreme, and i’m wondering if/when the weather pendulum will swing so far that this inevitable (mini) ice age i heard about will occur. do you have any comment about this? (in layman’s terms, please!)

    Comment by jen — 25 Sep 2013 @ 5:53 PM

  34. ps — above Prokaryotes discovered the 2007 Tung paper.

    RC has discussed that one several times since it came out:

    Comment by Hank Roberts — 25 Sep 2013 @ 5:59 PM

  35. The “beam me up” explanation could be clearer. Here’s my stab at it:

    The rate of shallow ocean warming can decrease at the same time the rate of deep ocean warming increases. This can happen if something increases the amount of mixing between the (warm) shallow ocean and the (cold) deep ocean. The mixing transports heat from the shallow ocean to the deep ocean, thus cooling the shallow ocean while warming the deep ocean.

    Comment by Meow — 25 Sep 2013 @ 6:08 PM

  36. Cannot relate to Hiroshima bombs but as an Australian, relating to boiling Sydney harbour dry is more understandable, perhaps use one of the great lakes as an analogy

    Comment by john byatt — 25 Sep 2013 @ 7:14 PM

  37. @ Colin Johnstone

    Skeptical Science offers many posts translated into German, among other languages.

    Comment by Daniel Bailey — 25 Sep 2013 @ 7:40 PM

  38. Is this presentation wrong or right?
    It is of interest to know if Ocean heat Content is different in different oceans or parts thereof.

    Comment by Geoff Sherrington — 25 Sep 2013 @ 10:22 PM

  39. @10: I think you’re confusing the verb ‘to heat’ with the noun ‘heat’. To heat something does require a transfer of heat energy from some source to whatever is heated. But heat itself is a form of energy– the energy of random molecular motion.

    Comment by Bryson Brown — 25 Sep 2013 @ 10:53 PM

  40. Just curious, but you say “This is the only possible heat source.” Does not volcanism provide a source? The interior of the earth is a heat source, and there is poor understanding of the heat flux, its magnitude and how it varies over time. We continue to “discover” vast, active volcanoes in the deep oceans, could they not have an impact on ocean heat content and via that the atmospheric heat content? Some parts of the continental USA have a heat flux of the order of 10Wm-2, perhaps there are similar areas of high flux in the deep oceans?

    [Response: Not an absurd question, but in practice net geothermal heating (including volcanoes, mid ocean ridges etc) is about 0.075 W/m2 – some 20 times less important than human CO2 increases. – gavin]

    Comment by Surfer Dave — 25 Sep 2013 @ 11:41 PM

  41. How bad can the next El Nino be? This year for example we had 45.8C in Sydney on January 18 in a ‘neutral’ year. If cities with pampered citizenry nudge 50C for several days in a row the same time as electricity and water problems there will be major grief. Sure Baghdad does this but I doubt they have the nearby fire prone bushland or the high percentage of senior citizens as Sydney.

    Comment by Johnno — 26 Sep 2013 @ 12:13 AM

  42. RC has discussed that one several times since it came out

    There seems to be a 2007 article which mentioned the study and a few comments on that here

    Is there a recent discussion on solar cycle, a paper someone can recommend?

    Comment by prokaryotes — 26 Sep 2013 @ 12:55 AM

  43. I kind of answered my own question in #17 after working with the data myself. It is amazing how well the Southern Oscillation Index (from NCAR) fits to a temperature record such as GISS, and only shows deviations in recent years during the big volcanic disturbances.

    From this one index and the sporadic volcano data which temporarily suppresses the temperature, all recent natural variability seems to be accounted for and all that is left is an upward warming trend.

    Now I understand why Stefan and Tamino’s work is so straightforwardly practical.

    Comment by WebHubTelescope — 26 Sep 2013 @ 1:11 AM

  44. @25 – “Is the heat on the road to the abyss only in the NH?

    No. You are looking at only the top 700 metres of ocean. The North Pacific and North Atlantic subtropical ocean gyres are surface intensified, i.e. they don’t reach down as deep into the ocean as the southern hemisphere gyres. Contrary to your claim, most of the deep ocean warming is actually taking place in the southern hemisphere. See Roemmich & Gilson (2009) and an earlier paper by Josh Willis (I don’t have the details to hand).

    @38 – “It is of interest to know if Ocean heat Content is different in different oceans or parts thereof“.

    Well it certainly should be. As shown in Levitus (2012) most of the warming is beneath the subtropical ocean gyres. This is to be expected because the spin-up of the wind-driven ocean circulation speeds up the currents (Ekman transport) which carry heat out of the tropics in the near-surface layers toward the subtropical ocean gyres. Where the poleward & equatorward currents of this intensified circulation converge – the centre of the gyres – surface water is pumped downwards into the ocean interior in a process known as Ekman pumping. The downward flow is (partly)balanced by upward flow near the equator (Ekman suction). That’s largely why the central and eastern Pacific Ocean are cooler-than-average during La Nina – cold water is drawn up from deeper layers below, warm water is pushed down below surface in the western tropical Pacific, and the poleward (meridional)heat transport in the surface layers intensifies.

    @41 – “How bad can the next El Nino be?

    There are no hard and fast rules, but often when the wind-driven circulation spins up, as it is now, El Nino tends to be weaker. It’s complicated, but it may be easier to think of this phase of the circulation as La Nina-like. A far more interesting question is how strong El Nino will be in the future when this circulation becomes sluggish again, i.e. when we get an El Nino and the circulation is El Nino-like. The 1980’s and 1990’s El Nino were certainly much stronger when the circulation was weak, but there is the added complication of global brightening during that period.

    Comment by Rob Painting — 26 Sep 2013 @ 3:08 AM

  45. Without access to Abraham et al. 2013, i must ask if there is a discussion of it somewhere?

    Comment by prokaryotes — 26 Sep 2013 @ 5:30 AM

  46. Regarding those having troubles with the calculations: is an excellent resource.

    Comment by Adrian — 26 Sep 2013 @ 5:50 AM

  47. According to this article, “The amount of heat stored in the oceans is one of the most important diagnostics for global warming, because about 90% of the additional heat is stored there (you can read more about this in the last IPCC report from 2007). The atmosphere stores only about 2% because of its small heat capacity…”

    If the atmosphere accounts for only 2% of the energy, why are we so preoccupied with the global average temperature?

    [Response: Because that’s where we live. – gavin]

    Comment by KK Aw — 26 Sep 2013 @ 7:05 AM

  48. A question: the article leaves one with the impression that when (not if) there is a return to some strong El Niño events that surface temperature averages will resume their rise.

    Is it not the case that if the relative lack of El Niño’s and predominance of La Nina’s is in fact due to global warming, rather than natural variability, then the current increase in the rate of warming of the ocean below 700m may continue. If this is the case then this may result in a long term reduction in the rate of warming of land and surface ocean temperatures. So, although the science isn’t ‘wrong’ regarding the continued heating of the earth (net energy imbalance), the rate of rise of surface temperatures may prove to be much less than predicted by the models. Not much help though with sea level rise due to thermal expansion!

    Comment by Pete Wright — 26 Sep 2013 @ 7:43 AM

  49. The winds of change.

    The world awaits the shift of prevailing wind patterns across the equatorial Pacific to deliver a mean El Nino punch.

    Comment by John McCormick — 26 Sep 2013 @ 8:48 AM

  50. If the increased increasing energy is being distributed in the deep ocean, how does it get out into the troposphere?


    [Response: This is an odd question. The increase in OHC is an indication that the planet is in radiative imbalance (more energy is coming in than is leaving). This will only be balanced (in a quasi-equilibrium way) when the surface temperature rises sufficiently to increase the outgoing long wave radiation. Thus the OHC trend says that surface temperature trend has further to go. It has nothing to do with heat going into the ocean and coming back out. At equilibrium the ocean heat content will be much larger than it was (and the surface temperature warmer too). – gavin]

    Comment by Alan Millar — 26 Sep 2013 @ 9:13 AM

  51. @44
    The subtropical gye and Ekman transport only happens in the upper ocean (upper 700m), doesn’t it? If it is, how the heats are transporting downward and links to ENSO? (ENSO is also a signal in the upper ocean 700m). Is the heat transportation to the deeper 700m ocean due to vertical mixing or change of general circulation??


    [Response: Both. Vertical diffusion is slower, but happens over most of the oceans, while downward advection of anomalously warm water happens in fewer spots but is faster (the North Atlantic, ‘Mode’ water formation regions north of the Antarctic Circumpolar Current, shelf water formation in Antarctica). Tidal mixing (particularly around the coasts may also be playing a role. – gavin]

    Comment by Clj — 26 Sep 2013 @ 9:18 AM

  52. @48 If your speculation is correct, I assume that another consequence would be that, if/when concentrations of greenhouse gases start to drop, corresponding reductions in surface ocean/land temperatures would take place at a much slower rate than would otherwise be the case: the surplus heat stored in the deep ocean will gradually make its way to the ocean surface, and continue to warm the atmosphere for decades, if not longer.

    (I think that an anomalously warm ocean surface heated from below would lead to more evaporation, and the additional water vapor would give a positive greenhouse effect that would partially offset the effect of a drop in greenhouse gas concentrations.)

    Comment by Arne Melsom — 26 Sep 2013 @ 9:41 AM

  53. Thanks Rob for mentioning the ocean gyres. Further was all this forecasted, again Rob Painting wrote a very good blog on this topic too, in June of this year.

    A climate model-based study, Meehl (2011), predicted that this was largely due to anomalous heat removed from the surface ocean and instead transported down into the deep ocean. This anomalous deep ocean warming was later confirmed by observations.

    This deep ocean warming in the model occurred during negative phases of the Interdecadal Pacific Oscillation (IPO), an index of the mean state of the north and south Pacific Ocean, and was most likely in response to intensification of the wind-driven ocean circulation.
    Meehl (2013) is an update to their previous work, and the authors show that accelerated warming decades are associated with the positive phase of the IPO. This is a result of a weaker wind-driven ocean circulation, when a large decrease in heat transported to the deep ocean allows the surface ocean to warm quickly, and this in turn raises global surface temperatures.
    This modelling work, combined with current understanding of the wind-driven ocean circulation, implies that global surface temperaures will rise quickly when the IPO switches from the current negative phase to a positive phase.


    Comment by prokaryotes — 26 Sep 2013 @ 11:11 AM

  54. 53
    Arne Melsom says:
    26 Sep 2013 at 9:41 AM

    “(I think that an anomalously warm ocean surface heated from below would lead to more evaporation, and the additional water vapor would give a positive greenhouse effect that would partially offset the effect of a drop in greenhouse gas concentrations.)”

    How does the extremely cold water (2-3C)of the deep ocean, warm the 18C ocean surface water precisely?

    [Response: It doesn’t. However the gradient of temperature in the ocean is maintained (roughly) as a balance between mixing from above and advection of cold water (from the poles) below. If the surface cools, there is an anomalous heat flux up which will lead to a cooler deep ocean. This is simply a reduction in the downward heat flux, not an absolute counter-gradient flux. – gavin]


    Comment by Alan Millar — 26 Sep 2013 @ 12:28 PM

  55. “Response: Because that’s where we live. – gavin”

    Thanks Gavin, I needed a laugh. It’s nice to remind people of some of the real fundamentals. We don’t live in the PETM, we live here and now and this is the only climate we’ve got. It’s worth repeating the closing statement from the recent American Meteorological Society Climate Change Statement: Prudence dictates extreme care in accounting for our relationship with the only planet known to be capable of sustaining human life.

    Comment by tokodave — 26 Sep 2013 @ 12:50 PM

  56. Gavin,
    Just want to make sure I understand your response to Downpuppy’s query regarding translating heat into degrees (#11). There you said “10^23 J in the ocean … ~= 0.04ºC”
    1. Am I right to think that the heat figure being discussed (10^23 J) is calculated from temperature changes measured by these Argo bouys, and that your calculation is actually running in reverse from some earlier calculation that derived the heat figure? (That is, which came first?)
    2. If so, how much confidence should we have in the ability of these scientific instruments to measure temperature of the ocean that accurately?
    I don’t know anything about them, and hope you can tell me.

    [Response: The changes being measured are much larger than 0.04C since the variations in temperature are not even in space and time. Temperature changes are much larger near the surface, and there are substantial regional variations. The mean temperature change or the OHC increase is an integral over all of that and therefore can be estimated to higher precision than any individual reading (just like for the weather station record). The uncertainties due to sampling and measurement accuracy go into the error bars, and the trend is clearly significant. – gavin]

    Comment by Chopbox — 26 Sep 2013 @ 2:07 PM

  57. Meehl et al. (2011)

    Model-based evidence of deep-ocean heat uptake during surface-temperature hiatus periods

    There have been decades, such as 2000–2009, when the observed globally averaged surface-temperature time series shows little increase or even a slightly negative trend1 (a hiatus period). However, the observed energy imbalance at the top-of-atmosphere for this recent decade indicates that a net energy flux into the climate system of about 1 W m−2 (refs 2, 3) should be producing warming somewhere in the system4, 5. Here we analyse twenty-first-century climate-model simulations that maintain a consistent radiative imbalance at the top-of-atmosphere of about 1 W m−2 as observed for the past decade. Eight decades with a slightly negative global mean surface-temperature trend show that the ocean above 300 m takes up significantly less heat whereas the ocean below 300 m takes up significantly more, compared with non-hiatus decades. The model provides a plausible depiction of processes in the climate system causing the hiatus periods, and indicates that a hiatus period is a relatively common climate phenomenon and may be linked to La Niña-like conditions.

    Comment by prokaryotes — 26 Sep 2013 @ 2:39 PM

  58. The general pattern of warming and ocean circulation in the model, during these hiatus periods, is very similar to that which occurs over shorter timeframes in the La Niña phase of ENSO. Strong upwelling in the equatorial eastern Pacific brings cold water up from the deep, which cools air temperatures in this region. Meanwhile in the subtropics of each hemisphere, heat is piling up and being driven down into deeper layers.


    Not only does the climate model-based study, Meehl (2011), show heat is buried into deeper ocean layers when global surface temperatures stall, but it also presents plausible mechanisms in ocean circulation that transport heat down to the deep ocean. The general pattern of sea surface temperature during these hiatus periods is very reminiscent of a La Niña-like climate state.

    The regular nature of these hiatus decades in the climate model, indicate that they are simply periods of natural variability, which occur even in the presence of a long-term warming trend. This is supported by historic observations (Figure 1), which shows roughly decade-long hiatus periods in upper ocean heat content during the 1960s to 1970s, and the 1980s to 1990s.

    The natural variability ‘flip-side’ to these hiatus decades, are periods where there is greater-than-average surface warming (see inset in Figure 2). So at some point in the very near future we can probably expect surface temperatures to gather up a head of steam, and begin rising at a rapid rate.


    Comment by prokaryotes — 26 Sep 2013 @ 2:44 PM

  59. @52 – No, the subtropical gyres can reach down into the deep ocean. See the observations in Roemmich & Gilson (2009) – The 2004-2008 mean and annual cycle of temperature, salinity, and steric height in the global ocean from the Argo program. Only a snapshot of course, but note where the deep ocean warming (as indicated by the mean steric height over the period) is occurring.

    Ekman transport may be confined to the surface layers, but when the circulation spins up, the greater rotational speed of the gyre increases the rigidity of the Taylor column at its centre. The gyre shifts poleward and the column lengthens. The sum effect is to displace isopycnals (parcels of water of the same density) vertically in the column, i.e. the deep ocean warms. May be easier if you understand that the circulation in the surface layers is not closed, there is transport/seepage.

    As for ENSO. See figure 5(a) & (b) in Stefan’s post. Imagine the left-hand side is the western tropical Pacific Ocean, and the right-hand side the eastern tropical Pacific. When the easterly trade winds strengthen during La Nina it pushes water along the equator from the east to west. This occurs because the Coriolis Force is zero at/near the equator. That isn’t the case as one moves further away from the equator. Anyway, much of the heat is forced down below the surface in the west. That is one reason why sea level rise in the western Pacific basin is much higher than the global average throughout the period of satellite-based observation (1993-to present) – the wind-driven circulation moved to a more intense phase throughout the duration of satellite altimetry. Based on past observations, dating back to the 19th century, this is unlikely to last.

    Comment by Rob Painting — 26 Sep 2013 @ 3:15 PM

  60. Think of the ocean heating during La Nina as removing $80 monthly from a deposit of $100 monthly for a net deposit of $20 . During El Nino, you are removing only $70 monthly, for a net deposit of $30. Alana Miller asks: how can a withdrawal add $10 a month?

    Comment by t_p_hamilton — 26 Sep 2013 @ 3:29 PM

  61. But isn’t the ocean heat storage far, far, smaller than the GHG forcing/net human-made forcing.

    The 0-2000 metre ocean is only absorbing 0.5 W/m2/yr but the net Human forcing is going to be reported by the IPCC tomorrow as 2.3 W/m2/yr.

    [Response: Just W/m2, no ‘per year’ involved. The 2.3 W/m2 number is radiative forcing with respect to atmospheric conditions in 1750, and it would be roughly the imbalance you would get instantly if you swapped in present day CO2 concentrations etc. Given that the planet has already warmed up, some of that forcing has already been responded to. Indeed, if the forcing increased slow enough (or the Earth responded faster – for instance, if there weren’t any oceans), the temperature rise would basically just follow the forcing and you’d be hard pressed to detect an imbalance. The ~0.5W/m2 is the *remaining* imbalance and thus an indication of how much more the planet needs to warm in order to come to equilibrium (at constant atmospheric concentrations). – gavin]

    Comment by Paulw — 26 Sep 2013 @ 3:46 PM

  62. Is there any reason to believe that after these La Niña dominated years climate warming will ‘play catch-up’?
    That is should we expect greater than normal warming until we reach the average warming of the last decades (revert to the mean)?
    Or does this pause mean that it will take approximately 15 years longer to reach the global temperatures projected for the end of this century?

    [Response: Depends on exactly what is going on. The portion associated with ENSO won’t delay anything – you’d get back to the long term trend once we have a few El Niños. The portion associated with short term forcings (solar, unaccounted-for volcanic aerosols, undercounts of Chinese pollution) will depend on their long term evolution – if they stabilise, you’d get a delay. Any portion associated with a model over-sensitivity would imply a lower trend in the future. – gavin]

    Comment by Martin — 26 Sep 2013 @ 4:03 PM

  63. “10^23 J in the ocean = 2.8 x 10^8 J/m2 = 1.4 x 10^5 J/m2 over 2000 m depth ~= 1.4 x 10^2 J/kg ~= 0.04ºC (averaged over the whole depth). Much bigger changes are near the top though. – gavin”

    What is the measurement uncertainty of the temperature data that underlies the heat content calculation?

    Are there even thermometers that can reliably measure a difference of 0.04ºC?

    [Response: See above – gavin]

    Comment by Russ R. — 26 Sep 2013 @ 4:16 PM

  64. Paulw – Net forcing changes since the Industrial revolution (about 1.6 W/m^2 in AR4) are not the same thing as the current top of atmosphere radiative imbalance (about 0.5-0.6 W/m^2 over the last 30 years based on OHC) as the climate has warmed over that time, and has already reacted to much of that net forcing change. You are confusing a rate with a summation.

    The only way for the TOA imbalance to be equal to the net forcing change would be for the Earth to somehow not warm over the last 250 years in the presence of that imbalance. And that’s not the case.

    Comment by KR — 26 Sep 2013 @ 4:29 PM

  65. Will the rate of sea level rise, due to ocean warming and thermal expansion, be somewhat faster than predicted in previous reports? Thus the fact of the heat being stored more in the deep oceans is NOT some sort of climatic get-out-of-jail-free card?

    Comment by Nick O. — 26 Sep 2013 @ 4:33 PM

  66. Ocean heat content

    Comment by prokaryotes — 26 Sep 2013 @ 4:46 PM

  67. Re hiatus cooling periods, from Meehl et al. (2013)

    From five climate model runs of the 21st century the authors derive 500 years worth of simulations. The hiatus decades were chosen based on a slight cooling trend in global surface temperatures of less than -0.08°C per decade. Eight decades match this criteria and the composite of their surface temperature trends are shown in Figure 1(a). If a zero decade-long temperature trend were chosen as well, then there are many more decades that fall under that criteria, including three instances where no warming lasts for 14 years, and one where this persists for 15 years.

    For the accelerated warming decades the authors choose decades where the global surface warming is at least 0.41°C per decade (around twice the observed warming over the last few decades based on GISTEMP). Like the hiatus decades, these large values for the accelerated warming decades were chosen so that the trends were obvious. The composite of the trends for these accelerated decades are shown in Figure 1(b).

    It is apparent in Figure 1, that the hiatus and accelerated warming decades are virtually the mirror image of each other. The warm sea surface temperatures in the gyres, during hiatus decades, indicate convergence of near-surface currents and strong downwelling of heat. With accelerated decades the vertical, and poleward, transport of heat by the gyres seems to shutdown, enabling strong sea surface warming in the tropics – where most solar radiation enters the ocean. The strong warming in the polar regions is related to changes in the thermohaline circulation.


    Comment by prokaryotes — 26 Sep 2013 @ 5:20 PM

  68. 58
    prokaryotes says:
    26 Sep 2013 at 2:44 PM

    “Not only does the climate model-based study, Meehl (2011), show heat is buried into deeper ocean layers when global surface temperatures stall, but it also presents plausible mechanisms in ocean circulation that transport heat down to the deep ocean. The general pattern of sea surface temperature during these hiatus periods is very reminiscent of a La Niña-like climate state.”

    It is fine to have a hypothesis but you need a physical mechanism to go along with it.

    The oceans are stratified, warmer water floats on top of the huge volume of deeper ocean that is at maximum density and minimum temperature.

    Whilst cold water can sink as its density increases, say as it is cooled at the poles, warm water cannot do this. Without significant up or down currents, heat can only be exchanged by convection and that is a heck of a slow process. There are significant horizontal currents even in the lowest layer but apart from places where these currents hit continental land masses there is no way to get much up or down currents.

    [Response: See above – gavin]

    So how does this increased heat get down there? It would have to be a fast process or we would see significant heating of the ocean surface, which I don’t believe we have seen this century.

    Comment by Alan Millar — 26 Sep 2013 @ 5:38 PM

  69. Nick O, #65: Will the rate of sea level rise, due to ocean warming and thermal expansion, be somewhat faster than predicted in previous reports?

    This is very likely, because El Nino years getting warmer and are tied to anomalously high sea levels.

    Patterns of anomalously high sea levels are attributed to El Niño–related changes to atmospheric pressure over the Gulf of Mexico and eastern Canada and to the wind field over the Northeast U.S. continental shelf.
    Climatologies of sea level anomalies (>0.05 m) and daily-mean storm surges (>0.3 m) are presented for the 1960–2010 cool seasons (October–April) along the East Coast of the United States. (Sweet & Zervas 2011) Link

    One finds that both the red El Niño years and the blue La Niña years are getting warmer, but given that we have lately experienced a cluster of La Niña years the overall warming trend over the last ten years is slower. This can be thought of as the “noise” associated with natural variability, not a change in the “signal” of global warming.

    This is consistent with the finding that reduced warming is not mainly a result of a change in radiation balance but due to oceanic heat storage. During La Niña events (with cold ocean surface) the ocean absorbs additional heat that it releases during El Niño events (when the ocean surface is warm). The next El Niño event (whenever it comes – that is a stochastic process) is likely to produce a new global mean temperature record.

    Comment by prokaryotes — 26 Sep 2013 @ 5:40 PM

  70. “The uncertainties due to sampling and measurement accuracy go into the error bars, and the trend is clearly significant.”

    Then shouldn’t the error bars be displayed?

    [Response: The graphs are I think direct pulls from the NODC website, but we show the errors in our own publications i.e. right hand panel here:
    – gavin]

    And you didn’t actually answer the question about the measurement accuracy of the thermometers being used. (If you don’t know, that’s perfectly acceptable… I’ve tried looking for the info on the ARGO website, and can’t find it.)

    [Response: CTDs measure at the thousandth of the degree level. Argo floats will be similar. Errors associated with sampling are the bigger issue. – gavin]

    Comment by Russ R. — 26 Sep 2013 @ 5:42 PM

  71. I obviously meant conduction not convection in my last post. Doh!!


    Comment by Alan Millar — 26 Sep 2013 @ 5:50 PM

  72. So how does this increased heat get down there?

    Rob Painting: The transport of heat down into the surface to deep ocean occurs via the subtropical ocean gyres. These are large rotating masses of water, in each ocean basin, where ocean currents converge at their centre and are forced downwards, taking warm surface water with them. Link

    Kevin Trenberth: We have just published a new analysis showing that in the past decade about 30% of the heat has been dumped at levels below 700m, where most previous analyses stop. The first point is that this is fairly new, it is not there throughout the record. The cause of the change is a particular change in winds, especially in the Pacific Ocean where the subtropical trade winds have become noticeably stronger, thereby changing ocean currents and increasing the subtropical overturning in the ocean, providing a mechanism for heat to be carried down into the ocean. This is associated with decadal weather patterns in the Pacific, which are in turn related to the La Niña phase of the El Niño phenomenon.

    The second point is that we have found distinctive variations in global warming with El Niño: a mini global warming, in the sense of a global temperature increase, occurs in the latter stages of an El Niño event, as heat comes out of the ocean and warms the atmosphere. There are also distinctive volcanic eruption signals in the ocean heat content record. So these affect the perceptions of global warming. Normal weather also interferes by generating clouds that reflect the sunshine, and there are fluctuations in the global energy imbalance from month to month. But these average out over a year or so. Another prominent source of natural variability in the Earth’s energy imbalance is changes in the sun itself, seen most clearly as the sunspot cycle. From 2005 to 2010 the sun went into a quiet phase and the warming energy imbalance is estimated to have dropped by about 10 to 15%.

    Some of the penetration of heat into depths of the ocean is reversible, as it comes back in the next El Niño. However, a lot is not: instead it contributes to the overall warming of the deep ocean that has to occur for the climate system to equilibrate. It speeds that process up faster than generally assumed. It means less short term warming at the surface but at the expense of a greater earlier long-term warming, and faster sea level rise. So this has consequences. Link

    Comment by prokaryotes — 26 Sep 2013 @ 5:53 PM

  73. 60
    t_p_hamilton says:
    26 Sep 2013 at 3:29 PM

    “Think of the ocean heating during La Nina as removing $80 monthly from a deposit of $100 monthly for a net deposit of $20 . During El Nino, you are removing only $70 monthly, for a net deposit of $30. Alana Miller asks: how can a withdrawal add $10 a month?”

    This is not the same at all. This heat is hypothesised to be going into the deeper ocean which is extremely cold and is stratified.

    How does it ever get back out to warm the troposphere?

    [Response: Please read the previous responses. (Clue: it doesn’t). – gavin]

    If somehow and I can’t possibly imagine how, there was a huge increase in circulation between the surface and the deeper layers of the ocean, that would be disastrous for global temperatures but not upwards but downwards!

    Be thankful that the we are insulated from the huge volume of cold waters that comprise the ocean, because if it ever became far more mixed with the surface layers we would plunge into permanent glaciation.

    [Response: No – they would just warm up (just like they do everywhere there is upwelling). – gavin]


    Comment by Alan Millar — 26 Sep 2013 @ 6:03 PM

  74. Alan Millar,
    OK, think about this. Heat is transferred into the deep by winds increasing mixing. If warm water is mixing down, then cold water is mixing up, right. Now the water down below warms. The next time there is mixing, the water above won’t cool quite as much.

    Comment by Ray Ladbury — 26 Sep 2013 @ 6:29 PM

  75. “[Response: No – they would just warm up (just like they do everywhere there is upwelling). – gavin”

    We must be at cross purposes here Gavin because a much more well mixed ocean would be disastrous for surface layer temperatures and the impact on the Troposphere.

    The average temperature of all the oceans water is about 4c compared to the average of 17/18c for just the surface layer.


    [Response: I am aware. But you are thinking as if this is a closed system. It is not. Water at the surface that is below the equilibrium temperature will be warmed mainly radiatively until it warms up again. If the ocean was completely well mixed this would take a long time, and the total heat content would roughly quadruple by the time it stabilized. It would be an easy experiment to try in a GCM. – gavin

    Comment by Alan Millar — 26 Sep 2013 @ 6:38 PM

  76. For the past two years I have offered a US$1,000 wager to anyone (denialists or sane people) that rejects the proposition that there will be a new global high temperature record set within five years. I have made the offer to many hundreds of denialists, and none of them will take the bet. Golly, it’s almost as if they do not believe what they claim to believe.

    Comment by Desertphile — 26 Sep 2013 @ 6:50 PM

  77. Response: “I am aware. But you are thinking as if this is a closed system. It is not. Water at the surface that is below the equilibrium temperature will be warmed mainly radiatively until it warms up again. If the ocean was completely well mixed this would take a long time, and the total heat content would roughly quadruple by the time it stabilized. It would be an easy experiment to try in a GCM”. – gavin

    I am aware it is not a closed system, that is my problem.

    How, is it managing to receive all this increased energy and not significantly heat up the Troposphere, for which there is a quick mechanism for doing so, yet at the same time can heat up the deep layers of the ocean, for which there does not appear to be a quick mechanism to do so?

    [Response: Sorry, I’m not getting your point. The energy comes from the sun, and the ocean is heated from the surface. You posited a well mixed ocean (which implies infinite diffusion) so that is your mechanism for warming the deep. In the real world there are the mechanisms I listed above. – gavin]

    Comment by Alan Millar — 26 Sep 2013 @ 7:17 PM

  78. AM is suggesting water is trapped at depth. I have read references to the Peru-Chile Trench that described it as the site of significant upwelling. The trench is very deep.

    If you watch animations of La Nina, the trench is clearly visible as the source of very cold water. You can watch it spread out all the way across the equator. One wonders if we were to fill the trench, would ENSO as we know it survive?

    From what depth is this upwelling coming? I cannot believe it is not coming from very deep in the trench, the bottom of which is some 20,000 feet below the surface.

    Comment by JCH — 26 Sep 2013 @ 8:21 PM

  79. Gavin, your response to my question is like the drunk man looking for his keys under the streetlight. Man: Where did you lose your keys? Drunk: Over there. Man: Why are you looking for them here? Drunk: It is bright here.

    Comment by KK Aw — 26 Sep 2013 @ 8:46 PM

  80. > I cannot believe it is not ….

    Depends on when you’re talking about. Poking around, as with

    turns up journal articles aplenty.

    Just e.g.

    Comment by Hank Roberts — 26 Sep 2013 @ 10:12 PM

  81. KK Aw,

    It is not unreasonable to focus on the “sphere” where we (and many other species) live. Just because 2% is small compared to 90% doesn’t mean the 2% is unimportant. Global warming would be a non-issue if it were occurring on a lifeless planet like Mars (not that the deep ocean is lifeless, but much of what we care about is at the surface).

    Scientifically, global warming is defined in terms of surface (or near surface temperature) change, and this extends throughout the troposphere too. It is also a better understood metric than the changes in OHC. People have interest in different things, and this is useful: there is no one metric that fully encompasses what is going with a changing climate.

    Comment by Chris Colose — 26 Sep 2013 @ 11:42 PM

  82. Gavin
    “[Response: Changing a unit to have a small sounding number doesn’t actually change anything; neither the significance nor the accuracy. But if you want to play rhetorical games, go right ahead – though perhaps not here. – gavin]
    Isn’t it temperature in Centigrade that is originally measured by the ARGO floats? And if so, why change the unit in the first place?

    [Response: The relevant phenomena is the heat flux and so it’s measured in Joules, J/m2 or perhaps better, W/m2 to get the rate of change. If you were talking about direct temperature effects on fisheries or corals or something, degrees C would be more appropriate. – gavin]

    Comment by Sven — 27 Sep 2013 @ 2:46 AM

  83. @ 73 – “This heat is hypothesised to be going into the deeper ocean…

    See figure 1 in Stefan’s post. The deep ocean warming has been measured. Even if readers don’t understand the principles of oceanography it doesn’t matter, the warming of the deep ocean is taking place regardless.

    which is extremely cold and is stratified.

    You have that backwards. It’s the surface oceans that are stratified. The deep-abyssal ocean is relatively well-mixed. If you think about it just a little it’s straightforward to work out why.

    If somehow and I can’t possibly imagine how, there was a huge increase in circulation between the surface and the deeper layers of the ocean, that would be disastrous for global temperatures but not upwards but downwards!”

    Science is not constrained by your inability to understand how the wind-driven ocean circulation works, or to ignore explanations provided earlier in this comment thread. Anyway, didn’t Stefan already cover this contrarian meme in his Star Trek (quantum teleportation) argument?

    And no, there is no huge plunge in tropical or global surface air temperatures when the ocean circulation spins up because there is a near-compensating decrease in poleward heat transport via the atmospheric circulation. As the ocean circulation takes up the role of transporting heat poleward the atmospheric circulation spins down. When the ocean circulation is sluggish the atmosphere spins up. A good explanation of the details is provided here: Koll & Abbot (2013) – Why Tropical Sea Surface Temperature is Insensitive to Ocean Heat Transport Changes. They conclude:

    The goal of this paper was to explain why tropical SST is not strongly affected by changes in OHT. We find that higher OHT weakens the Hadley circulation,which reduces reflective cloud cover and, to a lesser extent, reduces the surface winds that sustain evaporation, allowing SST to remain almost constant over a large range of OHT states

    Now I suspect this information will have no effect on you, but as always this is really written for the benefit of rational readers. Science may not have all the answers, but there is a great deal more known about the ocean circulation than contrarians try to insinuate.

    Comment by Rob Painting — 27 Sep 2013 @ 4:11 AM

  84. kk AW,
    Were I a Coelecanth, I might find your criticism valid.

    Comment by Ray Ladbury — 27 Sep 2013 @ 8:38 AM

  85. I believe that Alan Millar is engaging in the fallacy of
    Argumentum sine filo.

    Comment by Ray Ladbury — 27 Sep 2013 @ 8:39 AM

  86. Question: when ice melts, does that not result in the storage of large amounts of latent heat in the meltwater? If there has been an aceleration in ice melt in Greenland and Antarctica, the meltwater must contain latent heat that would otherwise have gone into the atmosphere. If this is the case, how much of the heat entering into the ocean system rather than into the atmosphere is this latent heat?

    Comment by mike — 27 Sep 2013 @ 8:43 AM

  87. Mike,
    The “latent heat” in water would only be released if it froze again.

    Comment by Ray Ladbury — 27 Sep 2013 @ 10:07 AM

  88. @39 — Bryson, no. “Heat”, the noun, is quite pedantically and standardly defined in physics as energy transferred due to a temperature differential. The energy you refer to, the kinetic energy of random atomic and molecular motions, is termed “thermal energy.” Reference any freshman physics text on this matter…

    Comment by robert — 27 Sep 2013 @ 10:44 AM

  89. 83
    Rob Painting says:
    27 Sep 2013 at 4:11 AM


    Ray Ladbury says:
    27 Sep 2013 at 8:39 AM

    “I believe that Alan Millar is engaging in the fallacy of
    Argumentum sine filo”

    I am well aware of ocean circulation that interchanges water to and from the deep oceans.

    Again it is the time scales that is the problem. These Thermohaline circulations take hundreds of years or longer. The wind driven coastal upwellings are a tiny fraction of the ocean surface and volume.

    If the surface layer of the ocean is not quickly exchanging energy with the troposphere, which it can do easily and quickly but retaining the energy, why is it not heating up far more rapidly, If you are saying it is getting rid of it to the deep oceans, how precisely is it doing this so quickly?

    Please be precise about the mechanisms, volumes and timescales, just saying ocean circulations is not good enough, given what we know about the very long timescales involved to move the water.


    Comment by Alan Millar — 27 Sep 2013 @ 10:48 AM

  90. Alan Millar, in the original post at the top of the page, your question was answered before you asked it.

    … the wind is turned on. The surface layer … becomes on average colder (less red), the deep layer warmer…. like La Niña (cold eastern tropical Pacific). The winds are the trade winds….

    Remember — “If the Earth was an apple … the water layer would be thinner than the fruit’s skin”

    You’re confused by being very small, seeing the ocean as deep, vast, and its depths unreachable.

    Look at some of what’s been described just in the last few years. If you don’t want to make the effort to use Scholar, just look at, for example, Science Daily and search there. You’ll find, just as examples:
    “… another — possibly substantial — source of energy for mixing that’s generated in the ocean where cold, heavy water collides with warm, light water. … turbulence at a front near Japan that is 10 to 20 times more energetic than what the wind could generate…. is likely an extreme example of a process that occurs much more widely in the ocean.

    “It’s not just wind at work on the ocean. The enhanced mixing at this front is drawing energy from the entire North Pacific. That’s what’s really new”


    “… sea water mixes dramatically as it rushes over undersea mountains in Drake Passage — the channel between the southern tip of South America and the Antarctic continent. Mixing of water layers in the oceans is crucial in regulating Earth’s climate and ocean currents.

    The research provides insight for climate models which until now have lacked the detailed information on ocean mixing ….

    Comment by Hank Roberts — 27 Sep 2013 @ 1:02 PM

  91. Oh, and just because this stuff is wonderful — I mentioned this when the study came out, but I don’t know if the modelers have enough information to add it in:

    From 2009: “Kakani Katija and John Dabiri at the California Institute of Technology have developed a way to estimate the extent of “biogenic” mixing. After conducting field measurements on swimming jellyfish, they built models of how animals mix the waters ocean-wide and concluded that the effect may be extensive.

    “Swimming animals may contribute to ocean mixing on the same level as winds and tides,” says Katija. “This necessitates the inclusion of biogenic mixing sources in ocean circulation and global climate models.”

    And where are those organisms active? Well, that changes day to day. Tough to model, but living organisms aren’t trivial in affecting how climate works, and changes in what’s alive where and when are feedbacks to climate change.

    Comment by Hank Roberts — 27 Sep 2013 @ 1:06 PM

  92. I tried posting this yesterday and for some reason nothing happened so here goes again…

    The critical point we must not forget is that an increase in GHG creates an energy flow imbalance by slowing down the rate of energy loss to space from outgoing radiation. The only way you can balance the equation is by a temperature increase to increase outgoing radiation (or by changing the atmosphere in the opposite direction). If there is a “pause” in temperature change while the oceans absorb the excess, this isn’t a good thing. We are just changing the order of events a bit because an increase in surface temperatures would in any case eventually increase the energy content of the oceans.

    I have an article on one of my blogs about why we need to focus on energy.

    Ideally we should measure this energy imbalance directly but I seem to recall reading a James Hansen paper where he quantifies the net flow and explains why we cannot measure the difference between inflow and outflow to sufficient accuracy using satellites. But I would have thought rather direct indications of an increase in net planetary energy like rapid loss of Arctic sea ice should be enough to convince anyone that there has been no “slowdown”.

    Comment by Philip Machanick — 27 Sep 2013 @ 1:33 PM

  93. @89 – You misunderstand. It’s not my job to educate you about oceanography, that’s your job. You don’t appear to have read the papers I have previously referenced, so it appears ideological blinkers are preventing you from accepting the scientific evidence. This was apparent earlier in the thread, when you claimed the deep ocean warming was hypothesized. This despite the fact that the first graph in Stefan’s post stands out like a sore thumb, and shows the observed warming of the ocean down to 2000 metres.

    Why exactly should the ocean behave according to a hypothesis you appear to have formulated whilst sitting on your sofa? My advice would be to undertake tertiary studies in oceanography, then you actually understand the topic you erroneously think you know so much about, and can make some of the basic calculations yourself. Here’s a hint though: Earth’s rotation, and the division of the ocean into basins by the continental land mass configuration, play a large role in Ekman pumping and suction.

    Comment by Rob Painting — 27 Sep 2013 @ 1:38 PM

  94. Alan, we aren’t talking thermohaline transport. We’re talking wind-driven mixing. Not the same.

    Comment by Ray Ladbury — 27 Sep 2013 @ 1:47 PM

  95. 94
    Ray Ladbury says:
    27 Sep 2013 at 1:47 PM

    “Alan, we aren’t talking thermohaline transport. We’re talking wind-driven mixing. Not the same”

    I figured that is the only probable mechanism but where is this taking place in the volumes necessary to rid the upper layer of the extra energy so quickly?

    The coastal wind driven upwellings are well known and they drive a good proportion of the world’s shipping industry. Has there been a change there?

    Even so the proportion and volumes involved, of the total volumes, look far to small to get rid of the surface layers excess energy, nowhere near enough interchange.

    Where is this change in wind driven interchange happening and in what volumes? If it was very significant it would surely have a noticeable regional affect on troposphere temperatures which we would become aware of.


    Comment by Alan Millar — 27 Sep 2013 @ 5:45 PM

  96. Doh!

    Mean ‘fishing’ industry obviously.


    Comment by Alan Millar — 27 Sep 2013 @ 5:47 PM

  97. Alan, read the papers in the recent literature section cited above.

    Comment by Ray Ladbury — 27 Sep 2013 @ 7:17 PM

  98. Alan, glancing at what’s readily accessible from where you’re sitting would help you — otherwise you’re asking us to go find the review articles in the field and summarize them for you. If you let people know how much you’ve found out by looking, experts may show up to fill in real gaps. Asking questions that way works better.

    “What is important about X” is a homework-help question.

    Comment by Hank Roberts — 27 Sep 2013 @ 7:17 PM

  99. I thought the comments up thread about coal aerosols in China were interesting. Is there a relationship between the cooling these aerosols cause and the increase in trade wind strength? Could this be estimated using a climate model?

    Comment by Michael Sweet — 27 Sep 2013 @ 9:11 PM

  100. Recently, there has been considerable discussion of increasing Antarctic ice pack caused by increased winds. Since the Eastern Tropical Pacific is not entirely decoupled from West Wind Drift given the general pattern of circulation in the SE Pacific, the question arises is the magnitude of the observed overall energy difference in the recently observed “extended” La Nina phase of ENSO condition relative to the the “more normal” ENSO comparable in magnitude to energy associated with the apparent increase in winds and potentially currents around the Antarctic? Could such a coupling or partial coupling explain where the energy for a more “normal” ENSO is going? That is could the energy “missing or delayed” be going instead into a modified current pattern in SE Pacific?

    Presumably, it does take a lot of energy to move that much water faster, with the heat potentially being redistributed into deeper ocean layers associated with perhaps poorly understood fluctuations of the Antarctic convergence at depth? Or is it that the wind phenomenon of such short/local scale or that the circulation systems are known to be so completely decoupled that this isn’t possible and that some other explanation for the delay in the “normal” ENSO pattern is required?

    Are there good overviews as to how much annual/decadal variation there is in world ocean currents and could unexpected aspects of “trends” in their coupling explain where all the additional trapped energy is going?

    Of course, all this is of interest to an ichthyologist potentially interested in understanding where to look for expected changes in fish distributions given the tremendous diversity of depths occupied by different groups of fishes.

    Comment by Stuart Poss — 27 Sep 2013 @ 9:15 PM

  101. 98 Hank R said, “otherwise you’re asking us to go find the review articles in the field and summarize them for you”

    I don’t think so. There are plenty of folks here who already know the answer (to whatever his question was). He’s asking for 30 seconds of help.

    Comment by Jim Larsen — 28 Sep 2013 @ 3:13 AM

  102. “No best estimate for equilibrium climate sensitivity can now be given because of a lack of agreement on values across assessed lines of evidence and studies.”
    Sorry? All previous IPCC reports have included this, why, after more years of work, can this not be done now?

    Comment by Adam Gallon — 28 Sep 2013 @ 8:37 AM

  103. > whatever his question was

    His question appears to sum up to:
    “If [heat is mixing into the] oceans, how precisely is it doing this…. Please be precise about the mechanisms, volumes and timescales …. Where … this change in wind driven interchange happening ….”

    The original post and references answer much of that, but “precisely … be precise”? Maybe not.

    Comment by Hank Roberts — 28 Sep 2013 @ 9:42 AM

  104. Seasonal sea surface cooling in the equatorial Pacific cold tongue controlled by ocean mixing

    James N. Moum, Alexander Perlin, Jonathan D. Nash & Michael J. McPhaden
    Nature 500, 64–67(01 August 2013)

    Here we show the existence of a distinctive seasonal cycle of subsurface cooling via mixing in the equatorial Pacific cold tongue, using multi-year measurements of turbulence in the ocean. In boreal spring, SST rises by 2 kelvin when heating of the upper ocean by the atmosphere exceeds cooling by mixing from below. In boreal summer, SST decreases because cooling from below exceeds heating from above. When the effects of lateral advection are considered, the magnitude of summer cooling via mixing (4 kelvin per month) is equivalent to that required to counter the heating terms. These results provide quantitative assessment of how mixing varies on timescales longer than a few weeks, clearly showing its controlling influence on seasonal cooling of SST in a critical oceanic regime.

    Comment by Hank Roberts — 28 Sep 2013 @ 9:56 AM

  105. Church and White 2011 showed the forcing as accumulating compared to the accumulating ocean heat content and land/atmosphere/ice-melt energy accumulation.

    Comment by Paul Williams — 28 Sep 2013 @ 12:44 PM

  106. 103 Hank R says, ” but “precisely … be precise”?”

    LOL. So much depends on word choice. Back on topic, I’ve always been under the impression that a La Nina makes global warming worse as more energy gets stored in the system. Does that mean that the spike we’ll get when El Nino comes back will be a bit worse than without the recent La Ninas?

    Comment by Jim Larsen — 28 Sep 2013 @ 12:48 PM

  107. Hank @98, you may regret referring Mr. Millar to Eric S. Raymond. ESR’s advice to software hackers is excellent, but he apparently hasn’t applied it to his own understanding of climate science:

    I’ve written before about scientific error cascades and the pernicious things that happen when junk science becomes the focus or rationale of a political crusade.

    The worst example of this sort of thing in my lifetime, and arguably in the entire history of science, has been the AGW (anthropogenic global warming) panic. Now that the wheels are falling off that juggernaut, I’m starting to hear ordinary people around me wonder how I knew it was bullshit and hot air so much in advance…

    It seems that knowing how to ask questions doesn’t necessarily lead to enhanced apprehension of reality.

    Comment by Mal Adapted — 28 Sep 2013 @ 5:05 PM

  108. > ESR

    Doesn’t matter.
    Personality doesn’t matter.
    Science isn’t an admiration society.
    What matters is that the article gets cited.

    It’s a method for getting advice; it’s been cited, it’s instructive, worth reading and worth reading about.

    Comment by Hank Roberts — 28 Sep 2013 @ 6:28 PM

  109. “Depends on exactly what is going on. The portion associated with ENSO won’t delay anything – you’d get back to the long term trend once we have a few El Niños. The portion associated with short term forcings (solar, unaccounted-for volcanic aerosols, undercounts of Chinese pollution) will depend on their long term evolution – if they stabilise, you’d get a delay. Any portion associated with a model over-sensitivity would imply a lower trend in the future. – gavin”

    Several studies in recent years have shown an acceleration in the rate of heat accumulation in the oceans. I believe sea level rise has also accelerated a little. I know you have to be cautious but isn’t this a strong indication that the lower rate of surface and lower troposphere warming in recent years is due to natural unforced variability rather than climate forcings? It indicates that there has been no decline at all in the rate of heat accumulation in the climate system as a whole… if I understand things correctly.

    Comment by Icarus — 28 Sep 2013 @ 7:25 PM

  110. Heh. In the climate science context, Raymond’s best advice may be this:

    Don’t rush to claim that you have found a bug error in math or logic

    When you are having problems with a piece of software data analysis, don’t claim you have found a bug an error unless you are very, very sure of your ground. Hint: unless you can provide a source-code patch correct argument that fixes the problem, or a regression test against a previous version cite reliable evidence that demonstrates incorrect behavior clearly contradicts the analysis, you are probably not sure enough.

    Comment by Mal Adapted — 28 Sep 2013 @ 8:49 PM

  111. Isaac Held’s blog #41. The hiatus and drought in the U.S. mentions among other work

    Kosaka and Xie 2013, in which a climate model is manipulated by restoring temperatures to observations in the eastern equatorial Pacific.  I find the excellent fit obtained in that paper compelling, having no free parameters in the sense that this computation was not contemplated while the model, GFDL’s CM2.1, was under development, and the model was not modified from the form in which it was frozen back in 2005.   The explanation for the hiatus must, in appears, flow through the the equatorial Pacific. (I have commented on this paper further here.) These authors mention briefly an important  implication of this connection – the extended drought in the Southern US and the hiatus in global mean warming are related.
    Read the rest …

    Comment by Hank Roberts — 29 Sep 2013 @ 3:54 PM

  112. I have read the post twice but, as a non scientist, I am still struggling.

    Basic questions:

    1. What’s the margin of error on the .04 degree increase.

    2. Is the warming of the oceans only a modern phenomenon? If so, why?

    Comment by James — 1 Oct 2013 @ 4:26 AM

  113. James (#112) asks:

    “1. What’s the margin of error on the .04 degree increase.”
    Following the link to the source of the article’s figures leads you to figures including error bars:
    Also, the article states: “The 2-sigma uncertainty for 1980 is 2*10^22J and for recent years 0.5*10^22J”
    And 10^22J~=0.004C (assuming the energy is spread over the whole of the oceans) according per Gavin Schmidt (#11 response). Of course the energy is not uniformly spread and neither is the uncertainty. But that’s the assumption that got you 0.04C in the first place…

    “2. Is the warming of the oceans only a modern phenomenon? If so, why?”
    Of course not.
    It stands to reason that the oceans haven’t been that warm in a while but since the average temperature of the whole mass of water is so dependent on circulation (it’s only the surface temperature that’s constrained by its interactions with the atmosphere and space), I suppose a plausible history of that particular value would be very hard to reconstruct. But maybe someone knows better…

    Comment by Anonymous Coward — 1 Oct 2013 @ 5:34 AM

  114. @112 – the current long-term ocean warming is a result of increased greenhouse gases in the atmosphere. See this Real Climate post: Why greenhouse gases heat the ocean. Of course an increase in output of solar radiation could also warm the surface ocean, however there has been a slight decrease over the last few decades, so that can be ruled out.

    You may now understand why global temperature, i.e. ocean heat content, shows such a strong correlation with atmospheric CO2 over the last 800,000 years – as shown in the ice core records.

    Short-term variations in ocean heat uptake, such as the anomalous deep ocean warming of late, are due to changes in the vertical & horizontal distribution of heat in the ocean – mostly the wind-driven ocean circulation. Much of this is likely natural, however changes in aerosol forcing (say increased sulfate pollution from China up until 2007 – Klimont [2013], and increased emissions from tropical volcanoes) would also be likely to affect the ocean circulation too.

    Comment by Rob Painting — 1 Oct 2013 @ 2:22 PM

  115. Rate of change makes a difference; we’re causing change far faster than any natural event short of a supervolcano or asteroid impact, and we’re persisting at doing it. The changes include changes in wind patterns — so those are going to change how, where, and when and how much changes about how the upper ocean waves mix surface water. A quick glance for 2013 papers in Scholar:

    try skimming a few of the abstracts in the first few pages and remember you can refine the search as you figure out better words to look for or exclude.

    Comment by Hank Roberts — 1 Oct 2013 @ 5:02 PM

  116. #96 Lauri, Limit to Growth

    Unfortunately the hoped for decoupling of economic growth and use of materials seems an illusion:

    Part of the abstract:
    Metrics on resource productivity currently used by governments suggest that some developed countries have increased the use of natural resources at a slower rate than economic growth (relative decoupling) or have even managed to use fewer resources over time (absolute decoupling). Using the material footprint (MF), a consumption-based indicator of resource use, we find the contrary: Achievements in decoupling in advanced economies are smaller than reported or even nonexistent.

    Comment by Dick Veldkamp — 3 Oct 2013 @ 7:11 AM

  117. @59 (Rob Painting) My comment was regarding the equatorial Pacific, for which the second part of your post is relevant, not the first. As you will note from my initial post (@23), I speculated on what the effect would be if an aspect of climate change turns out to be a shift in the circulation with more frequent La Niñas and less frequent El Niños. But, as implied in my initial post, I really have no good reason to extrapolate the recent clustering of La Niñas into the future. So I absolutely consider your assumption that this clustering is unlikely to last to be much more likely than my thought experiment.

    Regarding the first part of your post, I’m well aware that dynamical forcing can shift the vertical position of isopycnals in the subtropical gyres. But in the absense of a global trend in the surface heat flux, wouldn’t this be a regional phenomenon that would be compensated by a lifting of the isopycnals in other regions? Alternatively, if a deepening of the subtropical gyres gives rise to an increase in the heat stored in this water mass, with a corresponding non-zero trend in the surface heat flux; then I should think that a restoration towards conditions of the past must somehow give rise to a delayed warming of the atmosphere (if the surplus is not somehow lost to space).

    Comment by Arne Melsom — 3 Oct 2013 @ 3:32 PM

  118. Gail, if you are reading Motl, then there is no point responding to you.

    Good luck, you’ll need it.

    Comment by Thomas Lee Elifritz — 4 Oct 2013 @ 5:39 AM

  119. Arne@117 – Sorry, my bad. My previous comment wasn’t addressed at you, but comment @51.

    Comment by Rob Painting — 4 Oct 2013 @ 5:39 AM

  120. Gail @118.
    You certainly have linked to a blogger who makes a serious error in judgement. He is way out of his depth. He has problems even with the concept of “average depth of ocean,” which is a worry given he is happy to wield mathematics involving integral calculus. Luckily he doesn’t attempt to use such equations but his reliance on a chum tweeting him the answer he wants suggests his chum is also a bit challenged on the subject of Ocean Heat Content.
    In truth, you don’t have to look very far on the web to stumble upon the answer the blogger was trying to obtain all ready completed for you. If you look, your will note there the bloggers second error (that is before he dissolves into incoherence). He calculates the warming over just the oceans and not the full globe. He is also oblivious to his comparison of a forcing (3.7 W/m^2) with an energy imbalance averaged over many decades. Indeed, he is oblivious to what a fool he makes of himself.

    The value that is perhaps more relevant than that addressed by your innumerate blogger is the present rate of increase in humanity’s positive climate forcing which was running at 0.43W/m^2 per decade to 2010. Comparing such an accumulative rate of increase with the 3.7W/m^2 for a doubling of CO2 – that is worth contemplating.

    Comment by MARodger — 4 Oct 2013 @ 7:44 AM

  121. Here’s another number for consideration. Ice mass loss in Greenland 2003-2009 as measured by GRACE amounts to 223 +/- 29 Gt/yr. If I did my latent heat calculations right, that’s 10^19 J per year just to melt that much ice. If I did my sums right, that’s about 100 Hiroshimas per second.

    Maybe we should just stick to nuking each other. Can we do a whole lot more harm?

    Comment by Philip Machanick — 4 Oct 2013 @ 8:07 AM

  122. Gail, if you average everything out, you get the average.

    Point is, with ocean heating, when the warm layer not disturbed so much by the wind, that layer stays on top, heat transfers to the atmosphere; when the warm layer is being mixed in more by the wind, less stays in the atmosphere.

    Motls seems to be describing something that doesn’t happen and saying that wouldn’t be a problem.

    Comment by Hank Roberts — 4 Oct 2013 @ 9:39 AM

  123. As I understand it the ARGO float program kicked off in 1999, only started to give meaningful ocean wide data by 2003 and was completed to planned 3000 ocean wide floats by 2007. My question relates to where ocean temperature data came from pre 2003? And what is its standard deviation? As we are talking about tiny hundredths of a degree measurements I am finding it very difficult to place any significance on pre 2003 data. If someone could please cover this off and explain how pre 2003 data was sourced I’d much appreciate it.

    Comment by John T — 16 Oct 2013 @ 8:06 AM

  124. for John T.: Revisiting Historical Ocean Surface Temperatures

    (I put your question in the Google search box and it led me to the RealClimate discussion about that, among other links)

    Comment by Hank Roberts — 16 Oct 2013 @ 11:17 AM

  125. I have a pair of questions and comments.

    I understood the mechanism related to the change in winds in the
    subtropical Pacific as driver for larger heat storage in the deep ocean
    vs. the upper layers described in the post; in Balmaseda et al. paper
    (doi:10.1002/grl.50382); and discussed several times along the comments
    of this post. -By the way, very interesting summary, as usually here.-
    What worries me is whether this mechanism also works during previous
    hiatus decades (as the 1960s) or not. In Balmaseda et al. paper, they
    show very nicely the changes in the ocean heat content (OHC) since the
    late 1950s and how during the last decade the OHC has substantially
    increased in the deep ocean while in the first 300 and 700 meters it has
    stalled. They relate the current hiatus period at the surface and a
    deeper penetration of the warming into the ocean with changes in the
    trade winds on the subtropical Pacific (intensification). However, these
    changes in the trade winds are only shown from 1970s onwards. Does
    someone known if a similar intensification of the trade winds took place
    during the 1960s explaining then that hiatus period too? And another
    question, why is the hiatus period during the 1960s not reflected in a
    larger heat storage in the deep ocean? Meehl et al., 2011
    (doi:10.1038/NCLIMATE1229) show that with a similar radiative imbalance,
    hiatus periods and non-hiatus periods can occur, and that in the first
    case larger heat storage in the deep ocean takes place. Unfortunately,
    the paper goes into future decades and not into previous decades. I have
    tried to find some radiative forcing time-series to check if during the
    1960s the radiation was balanced, but I haven’t found anything.

    These are my questions, and now just a comment. I agree with
    KrishnaAchutaRao that is inaccurate to say that “deeper than 2000 m not
    much happens”. It’s true that there are less observations and that they
    have received less attention. However, significant warming is being
    observed now not only in the Southern Ocean (Purkey & Johnson 2010), but
    also in the North Atlantic (Kouketsu et al., 2011 (doi:
    10.1029/2010JC006464); ICES Report on Ocean Climate 2011) and in the
    Arctic region (doi: 10.1002/grl.50775).

    Comment by Raquel Somavilla — 16 Oct 2013 @ 9:03 PM

  126. Raquel wrote: “What worries me is whether this mechanism also works during previous hiatus decades (as the 1960s) or not.”
    You shouldn’t generalize. Volcanism is thought to have made a comeback in the early 60s after 60 years of relative inactivity (at least as far as the volcanic forcing is concerned).
    Figure 9.17 of the AR5 draft doesn’t show much modelled OHC change in the 60s. Some models have a small increase, others a decrease.

    “I have tried to find some radiative forcing time-series to check if during the 1960s the radiation was balanced”
    Such a time-series would have to be a reconstruction.
    If you mean radiative disequilibrium, I guess this is would be highly model-dependent (like the OHC change).
    If you’re talking about the forcing compared to a preindustrial baseline, you might have a negative forcing during and shortly after the Agung eruption but the decade as a whole of course had a significant positive forcing compared to such a baseline due to the much higher GHG levels.
    There’s a difference because of preindustrial and 1960s temperatures were different.

    Comment by Anonymous Coward — 17 Oct 2013 @ 12:18 AM

  127. John T., see the XBT Network.

    Not to sound nasty but I’m in the same boat with you; my expertise doesn’t permit me to conclude that there is no significance to pre-2003 data. Same basic deal as if my radiologist says that tiny little black spot in the x-ray is something significant. I’m going to disagree? How? Way more importantly, why?

    Comment by Doug Bostrom — 17 Oct 2013 @ 3:20 PM

  128. There is one denialist argument that I hear but is not discussed in this post and that is “Only solar energy can warm the oceans.” Perhaps it’s so silly it’s not worth bothering with but it does point to holes in my knowledge. I’ve read the guest post from Peter Minnet but as far as I know the experimental data, while interesting, is not yet part of a peer reviewed study.So I’m not aware of solid evidence that CO2 directly warms the ocean.
    Can someone confirm or correct some things for me? It seems to me that a period where solar energy was entering and then quickly circulated into the depths would leave less IR radiation entering the atmosphere. That would mean less surface warming. Would the lack of cooling be evidence for the additional influence of CO2 et al?
    But as the sun has been been flat in the long term and cooling slightly recently how could it cause a consistent rise in temp if it does act alone? Are there other ways energy can enter the oceans? I’ve seen people say because of the energy imbalance it is obvious GHGs are causing the warming but I still don’t understand how.
    I appreciate any insight that can be provided. Thanks

    [Response: This whole issue is a complete red herring. Energy fluxes into the ocean are a combination of radiative (LW + SW), sensible and latent (and a bunch of small terms associated with rivers, icebergs, sea ice etc.). CO2 changes the LW fluxes directly and the other fluxes indirectly – and the net effect is to increase surface air temperatures over the ocean over what they would have been. That leads to a net heat flux into the surface ocean where it anomalously heats the mixed layer (and circulation slowly diffuses and advects that heat into the deeper ocean). It has almost nothing to do with any ‘direct’ heating of the oceans by CO2 directly, but rather follows from basic conservation of energy once the surface fluxes are modified by the higher CO2. – gavin]

    Comment by Wayne — 18 Oct 2013 @ 12:23 AM

  129. @126 (Anonymous Coward) Many thanks for your answer. I had some problems uploading my comment (125) to this post, and by the time you saw and answered my comment I had also already found the information that you provide me concerning the radiative forcing. Good to see that I am not missing anything important.

    Comment by Raquel So-mavilla — 18 Oct 2013 @ 4:37 AM

  130. @response to 128
    Thanks Gavin. Much appreciated.

    Comment by Wayne — 18 Oct 2013 @ 10:04 AM

  131. Could someone please offer an accepted definition of the term CAGW?

    [Response: An imaginary concept that is brought forth as an incantation whenever there is a need to ward off the possibility of serious discussion. – gavin]

    Comment by Radical Rodent — 21 Oct 2013 @ 4:50 AM

  132. Radical Rodent

    CAGW–the last refuge of the lukewarmer after they have exhausted all delusions that the planet isn’t warming or that it is due to anything but CO2. This is when they download the recording from the mothership that says: “Yes we are warming the planet, but it will all be good. La-la-la-la-la…”

    Comment by Ray Ladbury — 21 Oct 2013 @ 9:13 AM

  133. As I understand it, CAGW is an acronym for catastrophic anthropogenic global warming.

    Given that multiple catastrophes driven partly if not entirely by anthropogenic global warming have already occurred, I don’t see what is “imaginary” about it.

    Of course, ANY idea about what may happen in the future is, by definition, “imaginary”.

    But given that we have every reason to expect AGW-driven catastrophes to esacalate in both severity and frequency, it doesn’t take much “imagination” to expect that to occur, particularly if business-as-usual consumption of fossil fuels continues for many more years. Indeed, it would take a very active and determined “imagination” to come up with scenarios in which that will NOT occur.

    And if someone insists that the word “catastrophic” in that acronym can only properly refer to GLOBAL catastrophe, not “merely” a multitude of local, national or regional catastrophes, well, there are a number of readily “imaginable” scenarios for AGW-driven global ecological collapse and the mass extinction of most life on Earth that are well within the bounds of scientific plausibility.

    Comment by SecularAnimist — 21 Oct 2013 @ 3:41 PM

  134. > readily “imaginable” scenarios

    Imagination is a wonderful thing.
    It’s gotten us where we are now.

    Comment by Hank Roberts — 21 Oct 2013 @ 5:40 PM

  135. … the “Earth 2100” movie seemed CAGW enough to me (and plausible) – OTOH, if one is thinking of turning Earth into Venus, they’ll have to wait through some serious geologic time before that kind of C becomes likely, so far as I know (see Chris Colose’s info on that) (though I’d really still prefer it to be even later than that, frankly).

    Comment by Patrick 027 — 21 Oct 2013 @ 7:18 PM

  136. Hank Roberts wrote: “Imagination is a wonderful thing. It’s gotten us where we are now.”

    And it’s the only thing that has any hope of getting us out of the mess we are in now.

    I reject the idea that it is somehow inappropriate to acknowledge that catastrophic anthropogenic global warming is not only possible but plausible if we continue with anything close to business as usual consumption of fossil fuels and the other activities that are contributing to ever-increasing GHG emissions.

    And I also reject the notion that “it ain’t catastrophic” unless we are talking about some kind of “Venus effect”. The collapse of human civilization, the agonizing die-off of a large majority of the human population, and even the mass extinction of most life on Earth, are all quite plausible outcomes, and plenty catastrophic enough.

    Comment by SecularAnimist — 22 Oct 2013 @ 10:04 AM

  137. SA illustrates why the PR folks love the word “catastrophe” — when you use it to describe events covering the span from bad weather to extinction, it’s a rather broad brush claim

    > multiple catastrophes … have already occurred
    > …
    > The collapse of human civilization,
    > the agonizing die-off of a large majority …
    > the mass extinction of most life on Earth,
    > are … catastrophic enough.

    The deniers _love_ this language, because their target — selfish shortsighted readers — will think “Hey, we’ve seen a catastrophe and I feel fine — if that was catastrophe, what, me worry?” and they label people as alarmists.

    Bad weather a climate catastrophe, extinction a catastrophe: used that way, the word loses its significance.

    I’m reminded of earthquake magnitudes.

    So far we’ve seen magnitude 2.0 climate consequences.
    Those can’t be distinguished from natural weather extremes.
    Attribution takes hard scientific work.

    Just you wait.

    9.0 and above — Causes complete devastation and large-scale loss of life.
    8.0 — Very few buildings stay up. Bridges fall down. Underground pipes burst. Railroad rails bend. Large rocks move. Smaller objects are tossed into the air. Some objects are swallowed up by the earth.
    7.0 — It is hard to keep your balance. The ground cracks. Roads shake. Weak buildings fall down. Other buildings are badly damaged.
    6.0 — Pictures can fall off walls. Furniture moves. In some buildings, walls may crack.
    5.0 — If you are in a car, it may rock. Glasses and dishes may rattle. Windows may break.
    4.0 — Buildings shake a little. It feels like a truck is passing by your house.
    3.0 — You may notice this quake if you are sitting still, or upstairs in a house. A hanging object, like a model airplane, may swing.
    2.0 — Trees sway. Small ponds ripple. Doors swing slowly. But you can’t tell that an earthquake is to blame.

    Comment by Hank Roberts — 22 Oct 2013 @ 10:39 AM

  138. But I digress. My apology, Gavin, I’ll try to stay on topic.
    Mmmm, herring …

    Comment by Hank Roberts — 22 Oct 2013 @ 10:39 AM

  139. Back to CAGW, which isn’t about science or policy so much as it’s about language manipulation. It’s a cynical conflation of what the science says (AGW) with policy implications ( C ) implying that the science is driven by a political agenda. It’s a term of dog whistle art usually presented with sneering stridency so that there’s no missing the all the implied stock associations (ridiculous dirty hippy, chicken little, elitist, blah blah blah) and their pejorative, supposedly self-evident, intent.

    Comment by Radge Havers — 22 Oct 2013 @ 11:31 AM

  140. Radical Rodent says:
    ”Could someone please offer an accepted definition of the term CAGW?”

    CAGW or Catastrophic Anthropogenic Global Warming is the acronym used (mostly by those that don’t support taking immediate action on climate change) for the theory (or collection of hypotheses) that attribute most of the observed modern warming to human activities and warn that continuing similar activities (mostly emitting CO2) could result in warming that is dangerous to both civilization and a number of ecosystems. Those that don’t support immediate action on climate change are attempting to get the point across that it’s the “Catastrophic” part that supports the need for “immediate action”. After all, who’s going to expend a large amount of time and effort to curb IAGW (Inconvenient Anthropogenic Global Warming) or BAGW (Beneficial Anthropogenic Global Warming)?

    Personally, I don’t consider the use of the word “catastrophic” as an unfair characterization of the science as communicated by many reputable organizations such as NASA GISS:

    Research Finds That Earth’s Climate is Approaching ‘Dangerous’ Point

    “Based on climate model studies and the history of the Earth the authors conclude that additional global warming of about 1°C (1.8°F) or more, above global temperature in 2000, is likely to be dangerous.”

    However, there is no universal or a scientific criterion that I know of that specifically defines what would constitute a global catastrophe. Certainly most everyone would probably agree that a mass extinction would be a global catastrophe, but what % increase in weather/climate related disasters would constitute a global catastrophe? The answer to that question is probably considerably different among people of differing points of view.

    Comment by John West — 23 Oct 2013 @ 4:45 PM

  141. Wayne says:
    “There is one denialist argument that I hear but is not discussed in this post and that is “Only solar energy can warm the oceans.”

    That’s like saying only the furnace can warm the interior of my home. But adding insulation also increases the temperature inside my home even with the same furnace input. Akin to adding insulation to a home, enhancing the GHE is about retaining more heat in the system not adding more heat input.

    Comment by John West — 23 Oct 2013 @ 6:41 PM

  142. > there is no universal or a scientific
    > criterion that I know of that
    > specifically defines what would
    > constitute a global catastrophe.

    Flood stories. Every culture has at least one great one, sometimes more than one.

    Pacific Northwest for example.

    Comment by Hank Roberts — 23 Oct 2013 @ 10:36 PM

  143. I was going to say that “CAGW” is the squeaking sound emitted by somebody as they are dropped down the bore hole but others handled the question better.

    Comment by Doug Bostrom — 24 Oct 2013 @ 1:52 AM

  144. In response to John in 140, it seems to me that it may not necessarily be easy to answer the question as posed because of the preponderance of systems driven to conditions of self-organised criticality (SOC). SOC, particularly across interconnected systems, is perhaps not sufficiently addressed in many analyses, even though such phenomena (e.g. avalanche-type phenomena) are ubiquitous. There could, for example, be SOC events reflected in ice sheet dynamics, as oceanic heat transfer destabilises the Antarctic circulation, leading to acelerated ice sheet destabilisation. It would be interesting if those using climate models could clarify if they do observe SOC effects in their simulations, and particularly in simulations in which climate-ocean-ice sheet systems are integrated (if such are available today). This would help clarify (e.g. for policy makers) the degree to which coastal infrastructure (e.g. sewerage systems, petro refineries, nuclear fleet), all of which in themselves could give rise to serious issues under compromise conditions, may require SOC-informed protection strategies. The existence of SOC events in ecological systems, e.g. the ‘avalanche’ spread of wheat fungus (now affecting wheat crops), tree diseases, bat fungus (affecting the insect control services they provide), forest fires, etc, speak to the inherent nonlinear nature of the systems around us, and whose stability and resilience most of us take for granted.

    What is the degree to which SOC is addressed and/or revealed by the extensive, but often thematically-siloed, studies being carried out? Is there a chunk of the climate-change-radar-screen (concerned with nonlinear systems and their interconnections and coupled responses) missing?

    Comment by Michael — 24 Oct 2013 @ 8:50 AM

  145. By the way, John West’s hammering on the vagueness of ‘catastrophe’ gives an excellent example of someone in difficulty with the meaning of the word — just the kind of thing I was describing at 22 Oct 2013 at 10:39 AM. Thank you for that.

    Comment by Hank Roberts — 24 Oct 2013 @ 10:21 AM

  146. So I take it that the consensus view is that according to our best current scientific understanding, there is no possibility whatsoever of any catastrophic consequences of anthropogenic global warming; therefore to use the word “catastrophic” is irresponsible alarmism;, and therefore the deniers are actually quite right to accuse anyone who suggests that such outcomes are possible of being an irresponsible alarmist.

    Comment by SecularAnimist — 24 Oct 2013 @ 11:04 AM

  147. SA, no.

    ‘Catastrophic’ is not scientifically defined in this context, so it’s not a science word. Either you’re missing the resonance in the way this language is used and misused, or you’re making it more difficult than it needs to be. I’m not sure which.

    To put it into perspective for you, contrary to what you may imagine, I think it’s quite possible that the gauge on my internal catastrophe meter has a higher percentage of area marked as a red zone than yours, and that my indicator needle moves up faster and in bigger increments.

    There are no manufacturers’ specs for this, and no reputable climatologist is going to waste good grant money on monitoring my personal catastrophe meter in order to understand the physics of ice shelf collapse, for example.

    Comment by Radge Havers — 24 Oct 2013 @ 4:24 PM

  148. Radge,
    Actually, catastrophe does have a mathematical meaning

    Comment by Ray Ladbury — 24 Oct 2013 @ 6:23 PM

  149. Ray,


    Come to think of it, since you brought it up, it seems a fair question to ask: How integral to current understanding of climate is catastrophe theory?

    Comment by Radge Havers — 24 Oct 2013 @ 9:00 PM

  150. > So I take it that

    Only if you limit your choice to between black and white.

    You can do that, in many languages — pick two extremes, limit the words used to one from each end, and you’ve got it.

    In German: it’s either gemütlich or Götterdämmerung.

    In English, it’s either copacetic or catastrophic.

    But language is _so_ variegated.

    You could really do better, I think, with a scale at least as expressive as Richter’s.

    The real point is that the damage to the world isn’t just around a 1 or a 2 and it’s going up to 10 (or 11!)

    The point is that the damage to the world is beginning to be detectable — and it’s going up by orders of magnitude, not simple additive steps.

    Catastrophe, catastrophe, catastrophe, catastrophe …

    Inconvenience, life-threatening, massively damaging, catastrophic. There’s four steps for you. Find a few more.

    Words. They are more useful, the more you use (within reason)

    If you get the right words, people may begin to understand.

    Don’t misunderstand me.
    That would be rhetoric.

    We have real problems to deal with. And none of us are likely to live to see the worse half of the consequences we’re helping produce; we’ve barely had hints yet. Inconvenient, troublesome, nasty hints, so far.

    Comment by Hank Roberts — 24 Oct 2013 @ 9:16 PM

  151. Radge,
    I don’t think there are too many singularities one must deal with in climate studies. .

    Comment by Ray Ladbury — 25 Oct 2013 @ 8:37 AM

  152. Hank Roberts wrote: “Inconvenience, life-threatening, massively damaging, catastrophic.”

    Perhaps the effects of global warming have, so far, been merely “inconvenient” for you, Hank.

    For many, many thousands of people they have already been massively damaging and catastrophic, and not only life-threatening, but life-ending.

    Not everyone can sit in an ivory tower and intellectualize that it’s “alarmist” to call anything short of the Venus effect catastrophic. Not when their homes, livelihoods and communities — and even entire nations — are being destroyed.

    Hank Roberts wrote: “And none of us are likely to live to see the worse half of the consequences we’re helping produce.”

    Probably that’s true. Most likely, most human beings now living will be dead from AGW-driven famine and mega-drought and mega-fires and the collapse of infrastructure under the onslaught of weather of mass destruction, not to mention the ensuing wars and violent socio-political upheavals, before the “worse half” — the mass extinction of most life on Earth — occurs.

    We are playing with fire. But it’s considered too “alarmist” to use the word “fire”. And since it’s all-important to avoid being labeled an “alarmist” by the deniers, let’s just say we’re playing with, well, a little “inconvenience”. That’s more nuanced.

    Comment by SecularAnimist — 25 Oct 2013 @ 10:32 AM

  153. Hank:

    Inconvenience, life-threatening, massively damaging, catastrophic. There’s four steps for you. Find a few more.

    Too, a catastrophe for some may be unnoticed by others. The blizzard that killed tens of thousands of cows in South Dakota this month was arguably a consequence of AGW. It was certainly Catastrophic for the cows; somewhat less so for the cow’s owners, with federal aid (ah, irony). For me, it was just another sad headline, with no direct impact on my life whatsoever.

    Comment by Mal Adapted — 25 Oct 2013 @ 11:41 AM

  154. Sometimes it’s not what you say but how you say it. Right now I’m thinking that CFMF (Catastrophic Free Market Fundamentalism) might be an appropriate term. Anyway, if people are shooting at you, you have to be aware of your surroundings and the changing situation; and you have to be creative enough to adapt and flexible enough to both duck and stay out of the crossfire.

    Not that language can’t be appropriated, but it’s a tricky proposition — especially in a scientific forum. You want a firewall between the science side and the policy side that lets info flow to the policy side and keeps the politics, garbage, blow-back, whatever out of the science side.

    “Stark:This is my side, that’s your side! This is my side – stay on your side! My side, your side! My side! Your side! My side! Your side!” ~ Farscape

    On to the UV thread.

    Comment by Radge Havers — 25 Oct 2013 @ 4:17 PM

  155. Taking into account knock-on effects, something as seemingly mundane as being forced to move from a domicile in a relative hurry could be termed catastrophic. Not much imagination needs to be exerted to spin up a scenario. Catastrophe can sneak up on cat feet:

    — Couple nearing retirement have solidly established and financed plans covering remaining life-expectancy;

    — Marginal statistical shortcomings of couple’s home situated on floodplain or shoreline are revealed by weather event significantly exaggerated by climate effects;

    — Home is no longer useful;

    — Home is replaced by emergency expediencies including substantial destruction of retirement savings;

    — Effect on couple’s finances and hence future plans is for all practical purposes catastrophic.

    No portentous music or screaming or immediate excess mortality need accompany a catastrophe.

    Comment by Doug Bostrom — 25 Oct 2013 @ 4:22 PM

  156. Sanguine adaptationists should bear in mind that without consequences having catastrophic outcomes when examined and evaluated in detail, adaptation is neither required nor necessary.

    Picture an adapated versus unadapted New York City 100 years from now.

    To endorse adaptation is to endorse a catastrophic view of global warming.

    Comment by Doug Bostrom — 25 Oct 2013 @ 4:36 PM

  157. #156–Great link, Doug–thanks for that.

    Your point in #155 is a good one, too; we had a disaster (though not a catastrophe) back in 2011, when a tree–toppled by the 60-mph winds of a derecho–dealt our shack a $100,000 blow. Our insurance was good, luckily, which was what made it disastrous but not catastrophic for us personally.

    It also was much easier because of the scale involved: the destruction (and reconstruction) of the house was amazingly disruptive, yet we still had a fully functional community around us. We could still work and earn as before, we could visit the same friends, we could access all the usual services. And though finding a suitable rental home was a big pain, it was much easier than if we had been in the middle of a crush of refugees trying to do the same thing. (Truth be told, it was mostly a pain because we were picky.)

    But, like your hypothetical couple, there was no fanfare whatever. Our friends, neighbors and colleagues knew (and were supportive in various ways), but that was it. Did it have anything to do with climate change? We won’t know unless and until there’s a lot more known about the links (if any) between climate and such (relatively) small-scale features. From what I read in AR5, any such future attribution figures to be quite a ways off yet.

    Comment by Kevin McKinney — 25 Oct 2013 @ 8:21 PM

  158. Kevin, I shouldn’t have buried that NYT article in a link because it is indeed terrific. NYT allows a certain number of free reads/month; this one’s worth a token. Beyond the geekish details, watery drama underground tells us how blanket disparagement of government workers is equally as worthless as many other generalizations. They’re not called “civil servants” for nothing.

    Could New York City Subways Survive Another Hurricane?

    The short answer is yes, many, if attention is paid and we’re not hypnotized into engineered ignorance.

    People living in statistical margins will be [are] the first affected by climate change. Numbers will begin piling up as outcomes in particular contexts eat through margins and deeper into distributions. A lot of invisible catastrophes will eventually get the official imprimatur, later than optimum.

    Comment by Doug Bostrom — 25 Oct 2013 @ 10:46 PM

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