Levitus data on ocean forcing confirms skeptics, falsifies IPCC

The IPCC, in the AR4 working group one, stated what could be called the central claim of global warming, the estimate of the net radiative forcing.

“The understanding of anthropogenic warming and cooling influences on climate has improved since the TAR, leading to very high confidence that the effect of human activities since 1750 has been a net positive forcing of +1.6 [+0.6 to +2.4] W m–2.”

Remember a forcing is an imbalance that causes heating, like a hot plate heating a saucepan of water. While the forcing continues, the temperature of the water will continue to rise. Global warming is the theory that increases in anthropogenic CO2 in the atmosphere are producing a radiative imbalance, or forcing, causing the earth to warm dangerously.

The IPCC level of forcing equates to the stated estimates for doubling of CO2 from around 1.5 to 6C per doubling, and the central estimates of warming to the end of the century from increasing CO2 of about 3C.

The paper by Levitus et al. uses the array of ARGO floats, and other historic ocean measurements, to determine the change in the heat content of the ocean from 0 to 2000m, and so derive the actual net radiative forcing that has caused it to warm over the last 50 years.

“The heat content of the world ocean for the 0-2000 m layer increased by 24.0×1022 J corresponding to a rate of 0.39 Wm-2 (per unit area of the world ocean) and a volume mean warming of 0.09ºC. This warming rate corresponds to a rate of 0.27 Wm-2 per unit area of earth’s surface.”

To compare these figures, say the continuous top-of-atmosphere forcing is 1Wm-2, a figure given by Meehl and Hansen and consistent with the IPCC estimates. The forcing of the ocean from a TOA forcing of 1Wm-2 is a lower 0.6m-2 due to losses, estimated by Hansen.

The best, recent measurements of the forcing 0f 0.3Wm-2 are half these IPCC estimates. The anthropogenic component of the forcing is even less, as a large part of the 0.3Wm-2 in the last 60 years is due to increased solar insolation during the Grand Solar Maximum.

This mild forcing is right in the ballpark that skeptic scientists such as Lindzen, Spencer, Loehle and Idso (and myself) have been consistently saying is all that is justified by the evidence. It appears that Levitus et al. confirms the skeptics, and the IPCC has been falsified.

What commentary on Levitus do we hear from the alarmists? Skeptical Science ignores that the IPCC has been exaggerating the net forcing, and attempts to save face:

“Levitus et al. Find Global Warming Continues to Heat the Oceans”

Skeptical Science “Put this amount of heat into perspective”, in a vain attempt to sound an alarm by quoting a scenario that is almost insane, having a infinitesimally small probability of happening.

“We have estimated an increase of 24×1022 J representing a volume mean warming of 0.09°C of the 0-2000m layer of the World Ocean. If this heat were instantly transferred to the lower 10 km of the global atmosphere it would result in a volume mean warming of this atmospheric layer by approximately 36°C (65°F).”

To do this, heat would have to defy all known physics and move backwards, from the boiling water to the hot plate.

The ocean is a big place. The best evidence is that its heating very slowly, much slower than the IPCC projected, and just as the skeptics predicted. The ARGO floats are arguably the most important experiment in climate science. It is all about good science: directly measuring the phenomenon of interest with sufficient accuracy to resolve the questions.

UPDATE: data1981 explains.

It’s definitely a confusing issue. What we’re talking about here is basically the amount of unrealized warming, whereas the radiative forcing tells you the total net energy imbalance since your choice of start date (the IPCC uses 1750). So they’re not directly comparable figures.

The unrealized warming has been fairly constant over the past ~50 years whereas the radiative forcing increases the further back in time you choose your initial point. So if you look at the unrealized warming starting at any date from 1950 to 2010, it will be a fairly constant number. But the radiative forcing from 1950 to 2010 is larger than the forcing from 1990 to 2010, for example.

Hopefully I got that right.

No he didn’t.

UPDATE: Roger Pielke Sr has a post on this topic.

55 Comments

  1. Ftomas April 26, 2012 4:53 pm

    This is nonsense. The radiative forcing is a metric with respect to 1750, but is not an estimate of the historical imbalance at the TOA. It is beyond obvious that any warming of the surface (which there clearly has been) will reduce the actual imbalance even as the forcing is constant. Indeed, at equilibrium the forcing is unchanged, but the imbalance will be zero and the surface temperature will be at the new higher amount.

    Why do climate models have imbalances much less than the forcing if this is such a contradiction to the IPCC?
     
    Why Roger Pielke Sr thinks this makes sense is also a complete mystery.

    • Pielkesr April 26, 2012 6:22 pm

      Ftomas – The figure in the 2007 IPCC Statement for Policymakers for WG1 is contadictory. In the caption it reads

      Global average radiative forcing (RF) estimates and ranges in 2005 ………yet in the footnote they write

      “In this report, radiative forcing values are for 2005 relative to pre-industrial conditions defi ned at 1750….”
      They do not actually present the 2005 forcing but the caption implies they do. In the new assessment, they need to estimate the current forcings.

      Using the ocean heat content, one can ignore surface temperatures as a diagnostic of global warming and cooling as the ocean diagnosis is more robust, particularly since 2003. However, it is a measure of the radiative imbalance with respect to a selected base time.

      Please also see my new post  http://pielkeclimatesci.wordpress.com/2012/04/26/comment-on-levitus-data-on-ocean-forcing-confirms-skeptics-falsifies-ipcc-at-niche-modeling/

      • Pielkesr April 26, 2012 8:16 pm

        Tom Curtis                     

        If one could measure the heat content changes of the climate system (which is mainly in the oceans) with an accurate enough spatial resolution, one can obtain the climate imbalance at that time. Monthy (or annual) averages are used because the data do not have a fine enough temporal (and likely spatial) resolution for shorter time periods.

        The use of heat in Joules as the metric avoids any need to focus on a global average temperature trend at one x-y level (e.g. the surface).

        Please refer to these papers for more information on why the ocean heat content as the global warming/cooling diagnostic (the radiative imbalance) is the most appropriate metric;

        Pielke Sr., R.A., 2003: Heat storage within the Earth system. Bull. Amer. Meteor. Soc., 84, 331-335. http://pielkeclimatesci.wordpress.com/files/2009/10/r-247.pdf

        Ellis et al. 1978: The annual variation in the global heat balance of the Earth. J. Geophys. Res., 83, 1958-1962. http://pielkeclimatesci.files.wordpress.com/2010/12/ellis-et-al-jgr-1978.pdf

    • Anonymous April 26, 2012 9:31 pm

      Ftomas: Roger does know what he is talking about. This is basic physics. Watts per square meter is not a metric, is a rate of energy flow like the output of a light bulb. A light bulb will heat a surface until equilibrium is reached. At equilibrium the forcing is zero.

      The AR4 (and Hansen’s figure http://data.giss.nasa.gov/modelforce/NetF.gif) shows the forcing with respect to a baseline. Its increasing because the effect of CO2 is increasing. If you want the overall forcing from 1750 you would take the average, about 1Wm2. Thats the IPCC estimate.

      Its directly comparable to the observed warming of the system, which is the mostly due to heat in the ocean. Its 0.3Wm2. Big difference.

  2. Tom Curtis April 26, 2012 7:14 pm

    Pielke Snr assumes not only that the TOA energy imbalance is not reduced by the change in temperatures, but also that the feedback is instantaneous.  It is not.  Feedback is a response to changed temperatures, so it increases incrementally from zero at the time of the initial forcing to its full value once the equilibrium temperature response is achieved.

    Taking the forcing since 1750 as our base, the expected TOA energy imbalance will be approximately

    Forcing + feedback response to the temperature difference between 1750 and current – the change in OLR due to the temperature difference between 1750 and current.

    Because the feedback does not lead to runaway warming, as the temperature approaches the equilibrium temperature response, the TOA energy imbalance will approach zero.

  3. anthony April 26, 2012 11:05 pm

    Forcing is not a product of time; with a temperature response to a sustained forcing over time, as is supposed by increases in CO2, the temperature response is itself a negative feedback to the continued forcing via Stephan Boltzmann effects. This would mean a measure of the effect of a forcing after that forcing has been active for some time should show a lessor temperature response which would be reflected in turn by a reduced forcing.

    In this respect Levitus’s finding seem to be confirmatory.

    The other ramification is that this decline in forcing will mean that the predicted Equilibrium Climate Sensitivity temperature response in a few centuries time will not occur.

  4. Tom Curtis April 27, 2012 3:12 am

    Hansen et al 2005 find a TOA imbalance of 0.85 +/-.15 W/m^2 in 2003 from their model, giving a range from 0.6 W/m^2 to 0.9 W/m^2.  That range shows conclusively that Stockwell and Pielke have mistated the predictions of standard climate science with regard to the TOA energy imbalance.  Stockwell’s formula is simply an error.  

    The upper limit is the energy imbalance estimated by Trenberth and Fasullo.  In constrast, the TOA energy imbalance estimated only from the ocean heat content from 0-2000 m is 0.27 W/m^2 from 1955-2006 by Levitus et al.  Given that Levitus et al indicate that the 0-2000m OHC represents 93% of total heating, that 0.27 represents a 0.29 W/m^2 energgy imbalance over that period.  Still substantially less than the Hansen et al estimate estimate for 2003.

    The major cause for the discrepancy is the fact that the 2003 estiimate is for one year, not the full period.  In 1955, the Hansen et al estimate was approximately 0.1 W/m^2 and has increased approximately linearly since, ignoring the three large volcanic eruptions.  That means the average estimate over the period should be closer to 0.5 +/- 0.15 W/m^2 excluding the influence of the volcanoes, and significantly less than that including the volcanoes.  Calculating the exact average is beyond me.  In other words, any discrepancy between Levitus et al and model predictions is minor at most, and Stockwell and Pielke have certainly not demonstrated that it exists.

    The mistake Stockwell  makes, and which Pielke accepts is, however, much grosser than taking the peak TOA imbalance and assuming it is the time averaged TOA imbalance.  They actually take the net radiative forcing relative to 1750 in 2006 and treat it as the TOA energy imbalance, ignoring the evolution over time.  Rather than accept the predictions of climate science as determined by GCM’s, they have demonstrated very poor understanding of the theory the criticize, and manufactured a strawman to find an opponent within their capabilities.

    • Anonymous April 27, 2012 3:52 am

      The effectve forcings used in GISS by Hansen are shown here http://data.giss.nasa.gov/modelforce/ to be around 1.6Wm2 as of 2010, giving an average over the last century of around 0.8Wm2. Anyway, you acknowedge there may be a difference. How long will you deny the evidence that models have been exaggerating warming?

      • Tom Curtis April 27, 2012 4:27 am

        The effective forcings your link to are the radiative forcing in 2000 relative to 1750. Once again, the TOA imbalance does not equal the radiative forcing relative to a particular time period plus the feedbacks.  That equation is grotesquely wrong. Given that the choice of 1750 as the baseline for radiative forcing is a convenience only, taking Stockwell’s equation literally would mean that the TOA imbalance could as easilly be determined from the radiative forcing relative to the last glacial maximum, and be approximately 8 W/m^2 plus feedbacks.

        Finally, I do not deny that some unspecified models overestimate the warming, just as some underestimate the warming.  What you are wanting me to do, however, is to assert that the IPCC multi-model mean is over estimating warming without bothering with that trivial detail of showing that they actually do.  Hint:  to show that you need to show both that forcings have matched model projections, and that the observed rate of warming robustly (ie, is not sensitive to choice of an start and end points) and statistically significantly fails to meet the model projection.  Self described “skeptics” don’t bother with ensuring a match on forcing projections, persistently choose data that is very sensitive to end points (cherry pick) and ignore the fact that even so, the warming trend does not differ in a statistically significant way from the IPCC projections.

        • Anonymous April 27, 2012 5:20 am

          I take your point that the “effective” forcing in the figure has a different intended meaning to an actual, measured forcing, the effective forcing being a model-based hypothetical and not an actual measurable imbalance (and note Pielke’s reference to IPCC confusion). However, the time frames of the IPCC and Levitus appear to be comparable, as the effective forcing in Hansens figure is zero both at 1880 (the start of the figure) and at 1960, the start of Levitus’ figure and putative start of man-driven warming. In that case the Hansen continuous forcing be the time-weighted average of around half the peak value – would it not – which is 0.8Wm2 and still considerably above the Levitus figure of 0.27Wm2.

          A typical debating tactic of alarmists to dismiss someone’s observation if it has not been written up in a paper. Experience shows it would be ignored anyway if possible.

          • Tom Curtis April 27, 2012 6:22 am

            davids99us, by calculating an average of the forcing over time you correct one of Stockwell and Pielke’s two most egregious errors.  Or I should say partially correct, as the effect of major volcanoes reduces the time averaged forcing to less than half of the average of the start and end points.  But you are still not correcting for the false assumption that the TOA imbalance at a time, t, is alt least equal to the forcing at t relative to some earlier time.  

            In fact, it will always be less.  It will be less because the temperature has increased since 1750 (the reference time for the radiative forcing) thereby reducing the imbalance.  But it also less because the feedback only increases incrementally as the surface temperature approaches the equilibrium temperature.  That is an obvious consequence of the fact that feedbacks are a response to change in temperature, not a direct response to changes in radiative forcing.

          • Pielkesr April 27, 2012 8:26 pm

            TomCurtis     

            Please list succinctly your two claimed egregious errors           

        • Alex Harvey April 27, 2012 5:26 am

           Tom,

          So you are saying that Prof. Pielke’s formula

          global radiative imbalance =  global radiative forcing + global radiative feedback

          is just plain wrong?

          • Tom Curtis April 27, 2012 6:13 am

            Yes.  The correct formula is given in Winton et al, 2010, who writes:

            “”This model represents the time-varying global-mean net TOA radiative flux N, as the sum of a forcing R and a term proportional to the global mean surface temperature anomaly T: 
            N (t) = R(t) – lambda*T(t)

            Here N is positive down and lamda is the climate feedback parameter.”

            Using this formula, it is important to include feedback induced changes in albedo as negative terms in lambda.  Lambda, of course incorporate both the feedback and temperature response used in my earlier formula.

            http://www.gfdl.noaa.gov/bibliography/related_files/mw1002.pdf 

            I

          • Ldlasldlas April 27, 2012 11:06 am

             And lambda is to be adjusted to fit the models.

          • Tom Curtis April 27, 2012 1:07 pm

            It really annoys me when people’s sole contribution to a debate is simple sloganeering.  If you have nothing intelligent to say, do the intelligent thing and say nothing.

          • Ldlasldlas April 27, 2012 3:06 pm
          • Pielkesr April 27, 2012 8:23 pm

            Tom Curtis – You are actually the one who is in error if you are dismissing the formula for radiative imbalance that I present. It is just a statement of the conservation of heat in Joules. The radiative imbalance is a result of a difference in the heat input and heat output of the climate system system. The components of the heat input and output can be expressed as direct and indirect radiative forcing as we did in the report

             National Research Council, 2005: Radiative forcing of climate change: Expanding the concept and addressing uncertainties. Committee on Radiative Forcing Effects on Climate Change, Climate Research Committee, Board on Atmospheric Sciences and Climate, Division on Earth and Life Studies, The National Academies Press, Washington, D.C., 208 pp

            e.g. see http://www.nap.edu/openbook.php?record_id=11175&page=98

            What you are presenting is another way to obtain the radiative imbalance using the surface temperatures. The way we propose doing this is more robust as the ocean itself does the integration. Even Jim Hansen agrees with this approach.

          • Pielkesr April 28, 2012 12:54 am

            Tom Curtis – To make sure I am clear, the indirect radiative forcings as I wrote above include both non-immediate radiative forcings and other radiative feedbacks.  Other radiative feedbacks are discussed in Understanding
            Climate Change Feedbacks (2003)

  5. Tom Curtis April 27, 2012 3:23 am

    I have responded to anthony on Skeptical Science where I first saw his comment:

    http://www.skepticalscience.com/news.php?n=1413#79242 

  6. Alex Harvey April 28, 2012 5:58 am

    Tom,

    “But you are still not correcting for the false assumption that the TOA
    imbalance at a time, t, is at least equal to the forcing at t relative
    to some earlier time.”

    Okay.  Since humans increase CO2 monotonically, then averaged over some time period that exceeds ENSO variability, the TOA imbalance for such an interval ought to be > the TOA imbalance over an earlier interval – if temperature is somehow held artificially constant.

    You mention that temperature has increased, and this should have partially restored the TOA energy balance.  The increase in T since 1750 is about 0.8 K, and since 1960 about 0.3 K (from memory).  0.3 K is certainly small relative to the 3 K per 2xCO2 that is expected.

    At the same time, though, the CO2 forcing has increased, and this creates more imbalance.

    One would think that as an approximation, the additional forcing might cancel the effect of the temperature increase.  Thus, one would think that David’s comparison is reasonable.

    So, I think I understand the point you’re making, but lack the mathematical skills to quantify it.  Is it possible that someone could put numbers to it?

  7. anthony April 30, 2012 12:23 pm

    This needs to be clarified; Tom is saying that Levitus’s forcing figure is less than Hansen’s and indeed AGW theory because it is later into the forcing period after the system has already responded to the earlier forcing by producing a greater temperature and therefore there is less forcing to be had because there is less future temperature change to produce further forcing.

    A couple of things about this:

    1 The temperature since 1750 is MUCH less than would be expected from the AGW forcing; which is, I suppose, why so much interest is in the ‘hidden’ heat in the ocean.

    2 If forcing is to be expected to be less, as explained in the 1st paragraph, as the system gets closer to the higher equilibrium temperature then, as an unavoidable consequence, the future temperature must be less too.

    This final point makes a mockery of the notions of future, MUCH higher, equilibrium temperatures; unless the heat can be found to be in the oceans. BUT Levitus shows that heat is not in the oceans; or at least sufficient heat to produce the equilibrium temperatures predicted by AGW theory.

    At least that is my understanding; please feel free to critique.

  8. anthony April 30, 2012 1:25 pm

    And another thing,
    Tom has seen fit to lampoon at John Cook’s site my reference to Stefan
    Boltzmann as a limit to temperature increase by extra CO2;

    Tom Curtis at 13:21 PM on 27 April, 2012

    “anthony @16, predictions of the equilibrium
    climate response include the Planck feedback function which you describe (and
    which is explained in more detail by Chris Colose here). So your argument amounts to the claim that
    a prediction which incorporates the Planck feedback cannot be realized because
    of the Planck feedback.

    I still remain mystified as to why self describe “skeptics” think
    that simply citing a well known physical effect which is incorporated into all
    Global Circulation Models (GCMs) (as both the Planck feedback and Beer’s Law)
    will show the predictions of those GCMs to be false, without any need of
    calculation on their behalf. It is as though they thought yelling “But
    E=mc^2″ would disprove the special theory of relativity.”

    Tom has linked to Colose’s piece on climate
    sensitivity; Colose says this:

    “Note that the logarithmic relation suggests
    that the fractional change in CO2 is what is important, since every doubling
    produces the same effect.”

    This is not correct; for example by AGW’s own
    criteria:

    280ppm to 560ppm = 1.2c rise
    (on average each 100 ppm results in a .4 C rise)
    560ppm to 1120 ppm = 1.2c rise
    (on average each 100 ppm results in a .2 C rise)
    1120 ppm to 2240 ppm = 1.2c rise.
    (on average each 100 ppm results in a .1C rise)Colose uses an amount of 1C but the point is the
    same.

    The reason why this negative feedback to heating occurs is because of
    Stefan Boltzmann; as the temperature increases the radiation emitted increases
    in a non-linear fashion as I explained:

    From
    200K-250K radiated energy increases from 91-222 W/m^2 – an increase of 131
    W/m^2.

    From 300-350K
    radiated energy increases from 459-851 W/m^2 – an increase of 392 W/m^2.

    But Colose states:

    “The temperature response can then be linearly
    related to a forcing”
    How can that be when the radiation emitted does not have a linear
    response to temperature?

     

      
     

  9. Bjorn Hallberg May 24, 2012 4:26 pm

    This worries me a lot. Are we 100% sure that we can rule out natural variations, we have seen some significant changes in the past.
    English technical translator at http://www.native-translator.co.uk/

    http://www.facebook.com/bjorn.hallberg.1

  10. peter2108 June 5, 2012 5:00 pm

    It’s dana1981

  11. BenPal October 1, 2013 10:10 pm

    “and so derive the actual net radiative forcing that has caused it to warm”. What radiative forcing are we talking about? CO2, sun?