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Earth’s Energy Balance

August 13, 2014

By Paul Homewood 

 

David linked to a study of the Earth’s energy balance by Richard Allan. I was going to comment, but decided it was worth a quick post.

Here is Ed Hawkin’s summary of Allan’s paper.

 

Global surface air temperatures have risen less rapidly over the past 15 years than the previous few decades. The causes of this ‘hiatus’ have been much debated. However, just considering surface temperatures does not tell the whole story – a new analysis using satellite & ocean observations confirms that the Earth is still gaining energy overall.

Understanding how Earth is currently heating up helps us to gauge how much the planet is going to warm in the future. The bottom line is that Allan et al. (2014, open access) find that the Earth gained 0.62 ± 0.43 Wm−2 (uncertainties at 90% confidence level) between 2000-2012. This amounts to 320 ± 220 TW of energy, which is:

  • about 20x the total global energy generated by humans1
  • about half a day’s worth of solar energy every year2
  • equivalent to every person worldwide using 20 kettles each to heat the oceans continuously3

In addition, atmospheric model simulations using observed sea surface temperatures and radiative forcings are able to capture variations in this heating rate due to natural factors such as volcanoes (which cool the planet) and changes in the ocean relating to El Niño/La Niña (which have both cooling and heating effects) – see Figure below.

It was also found that heating of the planet increased from the 1985-1999 period (0.34 ± 0.67 Wm−2) to the 2000-2012 period (0.62 ± 0.43 Wm−2), despite slowing in the rate of surface warming. This suggests that the extra energy is warming deeper layers of the ocean.

Changes in Earth’s yearly average heating rate in observations and simulations 1985-2013. All lines were adjusted to match the observed average heating rate over the 2005-2010 period. [Taken from factsheet about Allan et al. (2014)]

1 20 ± 14x global energy generation of 16TW in 2006
2 16 ± 11 hours based on solar constant of 1360Wm−2
3 23 ± 16 kettles of 2kW each

http://www.climate-lab-book.ac.uk/2014/earths-energy-imbalance/

 

I would comment:

 

It seems to me that the most telling statement is

This suggests that the extra energy is warming deeper layers of the ocean.

In other words, they have no evidence that it is, but it must be somewhere so it must be somewhere they cannot measure it.

 

Don’t just take my word for this. In the Guardian last year, Professor Ted Shepherd, a leading atmospheric scientist and recently installed as Grantham Chair in Climate Science at Reading University, was quoted as saying:

The heat is still coming in, but it appears to have gone into the deep ocean and, frustratingly, we do not have the instruments to measure there.(My bold)

18 Comments
  1. Otter (ClimateOtter on Twitter) permalink
    August 13, 2014 9:27 am

    And of course NONE of it could POSSIBLY be radiating back out into space…..

    • David permalink
      August 13, 2014 11:27 am

      If it is, then satellite observations aren’t picking it up.

      If you click on the study link and view chart 2, in particular chart 2a, you will see that there’s been a distinct fall in observed outgoing long-wave radiation OLR since the early 2000s. Note: figure 2a shows ‘observations’, not modelled data (which is figure 2b).

  2. August 13, 2014 9:35 am

    Is it possible that the ocean heating, if any, is coming from inside the earth?

    • David permalink
      August 13, 2014 11:39 am

      Heat continuously enters the ocean from volcanic vents and especially mid ocean ridges. As far as I know this heat is mostly localised and tends to be rapidly dissipated. Also, I’m not aware of any study that claims there has been sufficient undersea volcanic activity to warm the global oceans to the extent observed over the past couple of decades.

      The observation that down-welling long-wave radiation (DLR) in the atmosphere has increased over the same period that outgoing long-wave radiation (OLR) has reduced (Allan et al. 2014 above) provides more than enough heat energy to warm the oceans to the extent observed. But the problem here is ‘what’s happened to the ‘more’ from the ‘more than enough’ bit?

      Geothermal activity doesn’t provide sufficient heat energy to explain the warming oceans and the observed radiation imbalance provides too much of it!

  3. David permalink
    August 13, 2014 11:24 am

    “In other words, they have no evidence that it is, but it must be somewhere so it must be somewhere they cannot measure it.”
    ____________________________________

    It’s true to say that all of the extra heat that *should* be in the earth’s ocean/atmosphere according to this study isn’t accounted for (‘the missing heat’!).

    However, there is some evidence of increased ocean heat content in the 0-2000m range between 1985 and the present and that (see in particular chart 2 here: http://www.nodc.noaa.gov/OC5/3M_HEAT_CONTENT/ )

  4. August 13, 2014 11:36 am

    I am surprised that Allan et al could be published. The paper does not come near the quality of the papers by Loeb et al on the same topics.

    In 2009, a group led by NASA’s Norman Loeb reported their study, “Toward Optimal Closure of the Earth’s Top-of-Atmosphere Radiation Budget” based on satellite observations. (J.of Climate, AMS, V.22, p.748.) This group found that the parameters used for the classical method cannot account for satellite observations.

    Loeb and his team demonstrated that the errors of calibration of the satellite instruments are greater than the flux imbalance calculated by Allan et al 0.62 Wm−2. Allan’s error bars of +/ 0.43 Wm-2 suggest spurious precision.

    Click to access 2008_JC_Loeb.pdf

    In 2011, Hansen and others revised the earlier estimates of energy imbalance to be +0.58 W/m3. (Earth’s energy imbalance and implications, Atmos. Chem. Phys., 11, 13421–13449, 2011)

    Hansen’s error bars were +/-0.15 Wm-2 indicating spurious precision.

    In 2012, Loeb and other published the paper, Observed changes in top-of-the-atmosphere radiation and upper-ocean heating consistent within uncertainty. (NATURE GEOSCIENCE j VOL 5 j FEBRUARY 2012)

    Click to access Loeb12NG.pdf

    Loeb’s two papers effectively demolish the work of Hansen et al (2005, 2011) by showing that the satellite energy estimates are more certain than the estimates based on ocean temperature data.

    Allan et al do not advance our knowledge beyond the work of Hansen and others prior to 2011 and do not take us as far forward as Loeb et al (2009, 2012). .

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

    The statement in the blog, “…the Earth gained 0.62 ± 0.43 Wm−2…” is misleading. Watts measure power representing energy FLUX imbalance, not a quantum of energy gained,

    http://www.energylens.com/articles/kw-and-kwh

    The statement “This amounts to 320 ± 220 TW of energy,..:” is therefore non-physical because watts measure power not energy. Power X time = energy

    To get the energy produced you should multiply the flux per square meter by the surface area of the earth (4*Pi*r2) in meters and divide by 1000. That will give you the number of KW-hours of energy.

    Keep up the good work but proofread a little more carefully..

    • August 13, 2014 2:28 pm

      The latter comments are Ed Hawkin’s, Frederick.

    • David permalink
      August 13, 2014 3:59 pm

      Fred,

      You say that Loeb’s two papers demolish the work of Hansen et al., yet the summary of Loeb et al. (2008) ‘Toward Optimal Closure of the Earth’s Top-of-Atmosphere Radiation Budget’ cites the estimate of Hansen et al. (2005) stating (my emphasis): “Our *best estimate* of the average global net radiation at the top of the atmosphere (TOA), defined as the difference between the energy absorbed and emitted by the planet, is 0.85 +/- 0.15 W m^2”. The Loeb et al. (2008) paper seems to be mostly concerned about calibration issues with the satellite data rather than with contradicting Hansen et al.

      Allan et al. actually cite Loeb et al. (2012) in this paper. They use it to ‘support’ their estimates of uncertainty (see 3. Methodology). Given the above, I don’t see how these two Loeb et al. papers contradict Allan et al. in any way.

  5. Paul2 permalink
    August 13, 2014 1:08 pm

    It’s obvious – not enough money is being spent tackling this problem:

    http://www.bloomberg.com/news/2014-08-12/europe-s-green-energy-rules-cost-u-k-156-billion.html

  6. Doug Brodie permalink
    August 13, 2014 7:41 pm

    Ed Hawkins uses the usual warmist trick of describing the energy imbalance with apparently humungous numbers in an attempt to scare and bamboozle the general public. However the energy balance gain between 2000-2012 of 0.62Wm−2 reported by Allan et al is only 0.18% of an effective Total Solar Irradiance of 340Wm−2, and as little as 0.06% allowing for the quoted uncertainties. This doesn’t seem very scary to me, even assuming it is correct. As already noted, the Ed Hawkins article is careless as he uses units of Watts for energy, e.g. “320 ± 220TW of energy”.

  7. David permalink
    August 14, 2014 8:51 pm

    Doug Brodie

    I find Hawkins to be one of the least ‘alarmist’ of the climate scientists who try to engage in the public debate.

    For instance, I know he challenged the SkepticalScience bunch on Twitter for their ‘4 Hiroshima bombs per second’ widget. Why make such a a comparison when the extra energy is mostly going into the ocean and may not resurface for centuries, and even then in a phased way? He was effectively accusing them of using ‘alarmist’ tactics, and I agree.

    And I think Hawkins’ comparison of “about half a day’s worth of solar energy every year” is pretty non-alarmist and apt.

  8. David permalink
    August 15, 2014 8:55 pm

    One final comment from me on this.

    Frederick Colbourne commented above regarding two papers by Loeb et al. that apparently contradicted the view expressed in the Allan et al. (2014). (As I commented above, I don’t believe that to be the case.)

    Loeb has just clarified his position on ‘The Pause’ in a recent presentation: http://climate.nasa.gov/news/1141/

    I like the last quote of Loeb’s from the article, paraphrased as:

    ‘It’s okay to be sceptical, as long as you are also reasonable.’

  9. winter37 permalink
    August 15, 2014 9:28 pm

    David,at 13.8.14,11:39am;by DLR,if you mean down welling long wave infra red radiation from the troposphere,it has no heating effect.Heat does not travel from cold to hot,or am I misunderstanding you .

    • David permalink
      August 15, 2014 10:21 pm

      winter37

      The heat energy coming from DLR is not something that is coming from outside known heat sources. It’s just a recycling of heat in the atmosphere.

      If you cover yourself with a blanket in bed at night you warm up. You haven’t introduced new heat to your bedroom. You’re just recycling heat energy that has already been generated and released (by you).

      Heat is not travelling from cold (the air in your bedroom) to hot (you). It’s being intercepted from its source (you) and being recycled. The effect is one of ‘warming’ (for you).

      No heat is being introduced from cold to warm. No scientific laws are being broken.

  10. winter37 permalink
    August 16, 2014 6:13 pm

    David.
    I assume then that your DLR is same as DWLWIR which originally was radiated from the Earth.You cannot use the same heat twice.Doesnt.happen,cant happen,otherwise our clever engineers would have produced a little gizmo to capture this cold radiation,and our energy problems would be over.
    Also a blanket does not warm you,that is,add heat to your body,it merely slows down the loss of heat by means of an insulator,the blanket.As your metabolism slows,you slowly cool,there are no perfect insulators.
    Heat only travels from hot to cold period.Which reminds me,I must ask Ed Davey how many ice cubes I need to wrap my kettle in to enable it to boil.

    • Phlebas permalink
      August 22, 2014 2:50 pm

      David is correct, and you are not. To use your ice-analogy, imagine you are in the vacuum of space. Then cover yourself in ice. You will get warmer. Now add a second layer of ice. Warmer still.
      No Laws of Nature have been molested in this thought-experiment. Insulation works. You are surrounded by examples in your everyday life.

  11. winter37 permalink
    August 23, 2014 6:18 pm

    Phlebas. I think that you misunderstand me. I was trying to use the ice not as an insulator,but simply to show that heat can not be transferred from a cold system(the atmosphere) to a warmer system(the earth),or as I attempted to illustrate to Mr. Davey in a simple way,back radiation from the ice will not warm the water in the kettle.

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