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Trenberth can't account for the lack of warming

What the science says...

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More up-to-date measurements show warming is consistent within observational uncertainties. Heat is continuing to build up in the subsurface ocean.

Climate Myth...

Trenberth can't account for the lack of warming
in one e-mail, a top "warmist" researcher admits it’s a "travesty" that "we can’t account for the lack of warming at the moment." As it happens, the writer of that October 2009 e-mail—Kevin Trenberth, a lead author of the warmist bible, the 2007 Intergovernmental Panel on Climate Change (IPCC) report—told Congress two years ago that evidence for manmade warming is "unequivocal." He claimed "the planet is running a ’fever’ and the prognosis is that it is apt to get much worse." But Trenberth’s "lack of warming at the moment" has been going on at least a decade. (Michael Fumento)

Increased concentrations of greenhouse gases, from the burning of fossil fuels, slows the loss of heat from Earth's atmosphere to space. This creates an imbalance between incoming solar energy and outgoing heat. The Earth will continue to warm until the balance is restored. 

Because this planetary heat imbalance is tiny compared to the energy coming in from the sun, and the heat being radiated back out to space, it is too small to be measured directly by satellites. Earlier attempts to quantify this planetary heat imbalance were made in Hansen (2005) and Trenberth (2009) using earlier climate model-based estimates. Hansen (2005) had this planetary imbalance at 0.85 (±0.15) watts per square meter, and Trenberth 0.9 (±0.5) W/m2, in the earlier part of this century.

An apparent mismatch between the modeled estimate and the heat that could be accounted for on Earth, led to well-known climate scientist, Kevin Trenberth to lament that it was a travesty. Trenberth was, of course, referring to the inadequate state of global observations, such as the sparsely sampled deep ocean among other things, but his comment was predictably distorted by misinformers and spawned a fake-skeptic climate myth of its own.

Loeb (2012) takes an updated look at the issue and finds that, using observations rather than modeled estimates, the Earth's energy imbalance is consistent with heat building up with the Earth system. They have this imbalance at 0.5 (±0.43) W/m2, much smaller than previous estimates, but the error margins are huge. Not unexpectedly the authors confirmed that heat is continuing to build up in the sub-surface ocean, which agrees with other recent sudies on ocean heat. The persistent energy imbalance measured by this study is essentially future global warming, or "warming in the pipeline". It puts paid to wishful thinking-based claims that global warming has halted.

  

Figure 1: typical dive cycle of the ARGO submersible float system - the most detailed set of ocean heat observations yet obtained. Image from UK Met Office.

An exercise in accounting

Earth's energy budget is determined by measuring how much energy comes into the Earth system from the sun, how much is lost to space as heat, and accounting for the remainder on Earth.  Very little of this Earthbound energy goes into warming the atmosphere and land because they have a limited capacity to store heat. Likewise the energy required to melt ice is comparatively small.  

The oceans, however, cover over 70% of the Earth's surface and, due to their enormous heat capacity compared to that of the atmosphere and land, store over 90% of the excess energy from global warming. Quite obviously then, accurate measurements of ocean warming are crucial to balancing Earth's energy budget.

A little ocean heat content history

The ARGO float network consists of 3000 autonomous devices, distributed around the world's oceans, that sink down to depths of up to 2000 metres taking measurements of ocean temperature, as they ascend up through the water column. The system began to be rolled out in 2000, and by 2003 made up the majority of ocean heat measurements. The full roll-out of the 3000 floats was completed in late 2007. Although ARGO has not been without it's fair share of problems (as with any new technology), it represents a vast improvement over previous methods of sampling subsurface ocean temperature, such as the expendable bathythermographs (XBT's).

These are ship-launched devices that unfurl a trailing a copper wire as they descend down into the depths. It's through this wire which temperature information is transmitted back to a data collection system onboard the ship. Unlike the ARGO floats, XBT's don't have pressure sensors to measure depth, instead this is calculated by the rate at which the XBT falls. This calculation is carried out by software embedded in the XBT, and this timestamping of the temperature data is how depth is determined. Unfortunately this method has led to numerous problems in the ocean heat content record. See Abraham (2011).

From 1990 to 2002 these XBT's made up the bulk of ocean heat measurements, however because they were sparsely sampled in both time and space, numerous corrections and mapping strategies have had to be employed to remove errors and bias from the data set. From around 2002-2003, during the transition from XBT to ARGO, global ocean heating seems to decline. See figure 2.  

Figure 2: 0–700m upper-ocean warming rates. a, Annual global averaged upper-ocean warming rates computed from first differences of the Pacific Marine Environmental Laboratory/Jet Propulsion Laboratory/Joint Institute for Marine and Atmospheric Research (PMEL/JPL/JIMAR) 0–700m OHCA curve using data from Argo and theWorld Ocean Database 2009  the National Oceanic Data Center (NODC) 0–700m OHCA curve, and the Hadley Centre 0–700m OHCA curve. Uncertainties for all annual upper-ocean heating rates are given at one standard error and are derived from OHCA uncertainties. b, Means and uncertainties at the 90% confidence level for 1993–2003 and 2004–2008. Adapted from Loeb (2012).

The light green area I've highlighted (in figure 2[a]) is the time period where the XBT were the dominant source of ocean heat content data. During 2003, when ARGO takes over as the major source of data, it's clear that the large year-to-year fluctuations abruptly shrink - an indication that the large variation was not real, but most likely a result of errors in the less accurate XBT-based system. 

Also notable is the substantial variation in ocean heating rates between the three different ocean heat content data sets. In figure 2(b) are shown the ocean heating rates for the three data sets and their uncertainties. The period where ARGO data makes up the bulk of data (2004-2008 in red) has a greater uncertainty only because their period of observation is much shorter (5 years), versus 11 years for the interval where XBT data predominates (1993-2003 in blue). These uncertainties in ARGO will diminish as the length of the observational record grows, and indeed a decline in the scale of the annual fluctuation seems be occurring even within the 2004-2008 period.   

The authors state:

"Although the different estimates of OHCA (ocean heat content anomaly) produce seemingly different estimates of interannual ocean heating rate variability, these differences are all within the range of observational uncertainty. The same conclusion is reached when ocean heating rates for 1993-2003 and 2004-2008 are compared (Fig. 2b). The decline after 2004 is therefore not statistically significant 3 , nor does it show up in a previous analysis of the Argo data."

ENSO-induced changes in radiation flux at the top-of-the-atmosphere

As mentioned in the introduction, the satellites which measure incoming and outgoing radiation at the top of Earth's atmosphere (TOA) cannot measure the small planetary energy imbalance brought about by global warming. It is over a hundred times smaller than the energy coming and going from the Earth. But, despite lacking absolute precision, the measuring instruments aboard the satellites are very stable. Therefore the large fluctuations at the top-of-the-atmsophere during ENSO (El Niño/La Niña) present another approach to tracking changes in Earth's energy imbalance. 

El Niño and La Niña are not only intervals when heat within the system is distributed around the planet, but also periods which see a net loss of heat by the Earth (El Niño) and a net gain of heat (La Niña). Over the long-term these intervals balance out to zero. This net loss/gain of planetary energy during El Niño/La Niña is ishown in figure 3 for the tropics (a) and the global situation (b).

 

Figure 3: Variations in TOA radiation and ENSO during the past decade. a,b, Anomalies in net radiation (NET), absorbed solar radiation (ASR), the negative of outgoing longwave radiation (-OLR), and two-month averages of the Multivariate ENSO Index (MEI) for 30 S–30 N (a) and globally (b). Positive/negative anomalies correspond to a gain/loss of Earth energy. Positive and negative values of MEI correspond to El Niño (red shaded) and La Niña (blue shaded) conditions, respectively. TOA radiation anomalies are determined from monthly averages by removing the seasonal cycle then smoothing with a twelve-month running mean. Adapted from Loeb (2012).

Ocean Heat Content versus TOA flux observations

In order to compare these satellite-based observations with ocean heat content it is necessary to anchor the data to an absolute scale. Rather than use a model-based estimate, as did Hansen (2005) and Trenberth (2009), the authors achieve this by calculating it from observations of ocean heat content (down to 1800 metres) from the PMEL/JPL/JIMAR data sets over the period July 2005 to June 2010 - a time period dominated by the superior ARGO-based system.

By combining the ocean heating rates, TOA observations (figure 4) and other energy storage terms (land, atmosphere warming and ice melt), the authors calculated Earth's energy imbalance from January 2001-December 2010 to be 0.5 (±0.43) W/m2. 

Figure 4 - Comparison of net TOA flux and upper-ocean heating rates. a, Global annual average (July to June) net TOA flux from CERES observations and 0–700 and 0–1,800m ocean heating rates from PMEL/JPL/JIMAR. Uncertainties for upper-ocean heating rates are given at one standard error derived from OHCA uncertainties. b, Net TOA flux from CERES, ERA-Interim reanalysis and the one standard deviation about the 2001–2010 average of 15 CMIP3 models (grey bar) are anchored to an estimate of Earth’s heating rate for July 2005–June 2010. From Loeb (2012).

An obvious feature of the satellite TOA observations (figure 4) is that they do not show a sharp decline between 2002-2005 - the time of the transition from XBT to ARGO. Again this suggests that the scale of the 'slowdown' over that period is simply an artefact of the changeover from one system to the other, and may not be real. While the TOA observations show far less agreement with the NODC and Hadley Centre OHC data sets, after 2004 they demonstrate moderate agreement with PMEL/JPL/JIMAR data sets (as determined by statistical analysis).

The authors also note:

"Changes in CERES net TOA flux also show remarkable consistency with simulations from the European Centre for Medium-RangeWeather Forecasts (ECMWF) Interim Re-Analysis (ERA-Interim) (Fig. 4b, green line), which are completely independent of CERES."

And:

"The rise and fall in CERES and ERA-Interim net radiation and upper-ocean heating rates after 2007 (Figs 2 and 4) is entirely consistent with variability linked to ENSO (Fig. 2) and shows no evidence of a discrepancy between TOA net radiation and energy accumulating in Earth's climate system"

More warming in the pipeline

To sum up:

  • Global warming is the result of a greenhouse gas-caused imbalance between incoming solar energy and heat that the Earth radiates away to space. Heat loss is reduced causing the planet to warm.
  • Previous attempts to estimate this planetary imbalance relied on climate models rather than observations because sufficiently detailed observations were not available then.
  • Loeb (2012) combined ocean heat content data, top-of-the-atmosphere satellite observations, heat absorbed by the land and atmosphere, and the energy required to melt ice. They found the global energy imbalance was 0.5 (±0.43) W/m2, smaller than previous estimates.
  • The uncertainties are large due to the short length of robust observations, and because ARGO only samples down to 2000 metres - less than half the average depth of the global oceans.
  • The huge margin of uncertainty and the disparate heating rates between the three ocean heat data sets vindicate Kevin Trenberth's appeal that "we (the scientific community) must do better", but they will improve as the length of the observational record grows, and if proposed deep ocean observations, such as Deep Ninja, are put into place.   
  • And perhaps most crucially of all, the persistent energy imbalance at the top-of-the-atmosphere (TOA) is representative of future global warming, or warming "in the pipeline." The Earth will continue to warm until the balance at TOA is restored

Last updated on 3 March 2012 by dana1981. View Archives

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Further reading

Kevin Trenberth responds to the misrepresentation of his words in The truth about carbon dioxide, climate and the weather.

Comments

Comments 1 to 32:

  1. Thank you very much for the excellent explanation.
    One point still puzzles me, though, perhaps because I’m Italian: the word “travesty”. According to my good old Oxford Dictionary it means “a description that intentionally misrepresents the original e.g. burlesque poem etc.” etymology being the Italian verb travestire = disguise. It somehow conveys the impression that the whole thing is a farce, a dress up, an attempt to deceive.
    I understand in private informal correspondence one doesn’t care much about wording, but, why didn’t he use pity or shame or bad luck?
  2. Gianfranco: "Travesty" is one of those words a lot of English speakers commonly misuse. In fact, many people use it as a synonym for "pity", but with extreme emphasis.

    John: Terrific post and explanation, by the way. I think this is a nearly perfect example of the way such wholly accurate and innocent statements can be misconstrued by those looking for a good misconstruing.
  3. You may try to know what "the science" (whatever that is) says, or you may try to know what the different scientists say. In the later case, and unless you think Roger Pielke sr. is not a scientist, you may be interested in this debate:

    http://pielkeclimatesci.wordpress.com/2010/04/16/is-there-missing-heat-in-the-climate-system-my-comments-on-this-ncar-press-release/
  4. plazaeme,
    i find weird your contrasting between science and scientists. But anyway, i find even stranger that a skeptic like Pielke fail to recognize the limitations of our observing system, which is the mantra of the skeptic world including Pielke.
    Trenberth's point is quite simple, we can not close the energy budget and this can not be explained just by errors in satellite measurements. The obvious conclusion is that our observing system is not fully adequate to the task. I would have guessed that everyone could agree.
  5. by the way, here is Science Perspectives article and here UCAR press release.
  6. I have a few questions...

    Where in Ternberth 09 does it state that satellites indicate an energy gap? In fact it says '[the ceres data]were adjusted to an estimated imbalance'

    Also, what do you think the author meant when he says 'or the warming is not really present?'.

    Finally, if the 'climategate' emails were written on public computers, as part of publicly funded studies, how can the author's have any expectation of privacy? And what is the basis of your claim that the emails were stolen?
  7. RE #6 hu?
    You say:Where in Ternberth 09 does it state that satellites indicate an energy gap?

    Trenberth 2009 states it is the difference between satellite measurements and ocean heat content measurements from ARGO ocean floats. And Trenberth says:

    ..."Their sum should amount to the sea level from altimetry estimates from satellites, but substantial discrepancies betweentrends of 2 mm/yr were found..."

    You say: Also, what do you think the author meant when he says 'or the warming is not really present?'. He is referring to perhaps the satellite observations are incorrect, which is discussed more in the paper on page 24. (See also John's post here too)

    You say: ...public computers...how can the author's have any expectation of privacy? And what is the basis of your claim that the emails were stolen?

    They are stolen because they were hacked and the Police are investigating.

    You can very certainly expect privacy. Even though one might be a public servant, nobody should have ther private correspondences delved into anyone who could misquote it. You may be dealing with sensitive information including defense, patents and communication with industry. Universities and staff have the right to protect their intellectual property. If an official inquiry demands the information stored on public computers then yes of course you would have to disclose the contents but only then.
  8. Thank you for your response yocta, but your answer does not address my question. Where does Trenberth claim satellites indicate an energy imbalance? (not a sea level rise).

    There are two satellite data-sets discussed in the paper, CERES and GRACE. Which one does Trenberth refer to with this warming quote, in your opinion?
  9. 'If an official inquiry demands the information stored on public computers then yes of course you would have to disclose the contents but only then.'

    But didn't that happen?
  10. Where in Ternberth 09 does it state that satellites indicate an energy gap?
  11. Anyone?....Anyone?...Bueller?
  12. hu?
    the TOA imbalance come from satellite data. Trenberth has referred to these data several times, for example here.
  13. Riccardo,

    Thanks for your reply, but referring to data is not claiming it indicates an imbalance.

    In fact Ternberth says quite clearly that the CERES data is 'adjusted'.

    Seriously, what am I missing here?
  14. hu?
    "referring to data is not claiming it indicates an imbalance."
    What's wrong with referring to data that shows imbalance?
    In the section "dataset" they elaborate on this and on the necessary adjustment of the absolute value of the imbalance.
  15. But Trenberth says repeatedly the data is 'adjusted' to show an estimated imbalance...not that the imbalance is shown by the data.
  16. 'A comprehensive error analysis of the CERES mean budget(Wielicki et al. 2006) is used in Fasullo and Trenberth (2008a)to guide adjustments of the CERES TOA fluxes so as to match the estimated global imbalance.'
  17. "There is a TOA imbalance of 6.4 W m−2 from CERES data and this is outside of the realm of current estimates of global imbalances (Willis et al. 2004; Hansen et al. 2005; Huang 2006) that are expected from observed increases in carbon dioxide and other greenhouse gases in the atmosphere."

    This means that the imbalance is there but it's absolute value is inaccurate.

    "The TOA energy imbalance can probably be most accurately determined from climate models and is estimated to be 0.85 ± 0.15 W m−2 by Hansen et al. (2005) and is supported by estimated recent changes in ocean heat content (Willis et al. 2004; Hansen et al. 2005). A comprehensive error analysis of the CERES mean budget (Wielicki et al. 2006) is used in Fasullo and Trenberth (2008a) to guide adjustments of the CERES TOA fluxes so as to match the estimated global imbalance."

    So they choose to take the value from Hansen et al. 2005 and adjust the CERES TOA fluxes to match this value.
  18. "There is a TOA imbalance of 6.4 W m−2 from CERES data "

    I'm not sure what this means...but it does not say CERES data indicates an imbalance at all.

    Where is this 6.4 W m-2 figure coming from?
  19. The truth is out there guys:



    FIRST hu?: If I remember from undergrad the 6.4W/m^2 is the difference between the energy Earth receives from the Sun (solar flux 1365W/m^2 minus the CERES global measured flux of reflected sunlight) and that which is emitted back to space as thermal infra-red light (again a flux globally measured by CERES).



    SECOND: If I were a climatologist (which I am not) before worrying about the +6.4W/m^2 CERES imbalance I would take a look at the latest peer reviewed engineering analysis of the quality of current CERES data from 2009 G. Matthews, “In-flight Spectral Characterization and Calibration Stability Estimates for the Clouds and the Earth’s Radiant Energy System” Journal of Atmospheric and Oceanic Technology. Vol 26, Issue 9, pp 1685-1716. This explains how CERES solar wavelength calibration suffers un-directly detectable in-flight contaminant degradation and ultimately is based entirely on a reference radiometer on the ground which itself has never been measured and whose mirrors are >13 years old.
  20. Gianfranco at 20:14 PM on 31 January, 2010

    [. . .]One point still puzzles me, though, perhaps because I’m Italian: the word “travesty”.
    [. . .]
    I understand in private informal correspondence one doesn’t care much about wording, but, why didn’t he use pity or shame or bad luck?

    *************

    Trenberth was probably thinking of the word tragedy.
  21. Has there been any comments (here or elsewhere) on the paper by Knox & Douglass from 2010 regarding their findings refuting, apparently, Trenberth's analysis? I know there was some discussion on Curry's blog, but I prefer to not dive into the comment section over there. Thanks.
    Response: [Daniel Bailey] Pielke has a post up on it here. Trenberth is said to be preparing a takedown on it as well. An open access copy of the Knox & Douglass paper can be found here.
  22. Thanks Daniel (The Yooper).
    Response: [Daniel Bailey] You're welcome. And apologies; I forgot to mention there is discussion of the Knox and Douglass paper in this post here at Skeptical Science. My bad.
  23. So Ken, do I understand by "missing heat", that you mean that you will accept AGW if better measurements can close the energy budget, but in the meantime you will choose to believe that "missing heat" means that energy imbalance isnt real and we are not warming?

    I must it is refreshing for a skeptic to give an unequivocal statement of what data would persuade them to change their mind. Well done.

    (This is response to comment in another thread
  24. "So Ken, do I understand by "missing heat", that you mean that you will accept AGW if better measurements can close the energy budget, but in the meantime you will choose to believe that "missing heat" means that energy imbalance isnt real and we are not warming?"

    The energy imbalance is as real as the reality of our measurement.

    I have never argued that we have not had warming (0.75 degC surface since AD1750). The energy absorbed to produce that temperature increase is in the past.

    If surface temperature rise is flattening and heat increase in the oceans is also flattening with better measurement then a reasonable conclusion is that heat imbalance is reducing. The missing heat might stay missing because it was never there.
  25. Indeed. One of many things that would change my mind. 5-10 years on though, and with measurements improving, if the "missing heat" is accounted for, are you changing YOUR mind?
  26. If the facts change and the measurements are robust - of course I would change my opinion.

    We are all searching for the truth here. My constant theme is that the AGW case is not as strong as projected by the 'enthusists' precisely because the measurement is deficient. 'Correcting' the CERES imbalance to match the theory and calling that supporting evidence is not science.

    Elements of the theory also have wide error bars - eg. clouds and feedbacks.

    I am not claiming that there are not bogus arguments on the 'denier' side as well. Of course there are.

    However two wrongs don't make a right.
  27. Follow-up ...

    It looks like the missing heat in Earth’s energy budget has been found. Apparently, it’s in the deep ocean. The paper below concludes “the ocean has absorbed considerably more heat than reported by observations, particularly below 700 m”.

    Tracking Earth’s energy: From El Niño to global warming
    Kevin E. Trenberth and John T. Fasullo
    National Center for Atmospheric Research
    May 15, 2011

    Tracking Earth’s energy: From El Niño to global warming
  28. Well, the words before the start of the quotation you give are, "...analysis of model results suggests that...".

    Basically, they found that 'slowdowns' in upper ocean warming similar to what has been observed recently also show up in many model runs... and when they do the reason is consistently that the heat has been deposited deeper in the oceans. That is suggestive but certainly not definitive.
  29. It should be stressed, I think, that Trenberth's "travesty" is still not completely resolved: only a partial amount of the "missing" heat has been (likely) found; there is still some heat that we know for near certainty that Earth has accumulated (via radiative measurements "in" and "out"), but where it all is has yet to be determined. I am not convinced Trenberth Fasullo (2011) has accounted for the bulk of the "missing" heat, due to the error bars.

    The "breakfast napkin" sum I did with the 2011 paper shows some 0.13 w/m^2 to 0.28 w/m^2 missing if the ocean retention hypothesis is correct (which it almost certainly is, but it might not be). The median of the "missing" heat has not been observed (yet).

    There is a grant proposal being submitted to a few science organizations that seeks to measure the increase (and decrease) in oceanic heat in all four dimensions (i.e., cubic meters over time) to a depth of about 2000 meters. How to do this is a very difficult problem, and it would take an massive amount of money to do properly, and that money will never be provided; but the grant proposal is to perform a short term (minimal ten years) sampling every ten meters. Each buoy would have 200 temperature probes. The problem is that the expense is so great that only a few (30 or so) could be funded, and that is no where near as many as needed: the world's oceans take up a very large volume. The project may never be funded, even for the 30 hoped-for buoy systems.

    The bottom line is that humanity will never measure with confident accuracy all of the heat gain and loss going on in the oceans. We can at best measure surface and near-surface temperatures, and thereby infer heat, but the error bars will always be wide.
  30. Desertphile - see the advanced version of this rebuttal. The global energy imbalance observed in Loeb (2012) is 0.5 (±0.43) W/m2.

    Don't know where you get your information from, but it is not correct.
  31. Mods,

     

          Please note that the link to the Trenberth paper is broken and should point to 

    http://www.cgd.ucar.edu/staff/trenbert/trenberth.papers/EnergyDiagnostics09final2.pdf

  32. FOUND - Missing Global Warming from Science Magazine

    Major climate data sets have underestimated the rate of global warming in the last 15 years owing largely to poor data in the Arctic, the planet's fastest warming region. A dearth of temperature stations there is one culprit; another is a data-smoothing algorithm that has been improperly tuning down temperatures there. The findings come from an unlikely source: a crystallographer and graduate student working on the temperature analyses in their spare time.

    http://www.sciencemag.org/content/344/6182/348.summary

    Response:

    [JH] Hot-linked the url. 

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