Unbalanced At The Top

Guest Post by Willis Eschenbach

The “CO2 Roolz Temperature” theory goes like this:

    • The amount of atmospheric CO2 increases.

    • This absorbs more upwelling longwave radiation, which leads to unbalanced radiation at the top of the atmosphere (TOA). This is the TOA balance between incoming sunlight (after some is reflected back to space) and outgoing longwave radiation from the surface and the atmosphere.

    • In order to restore the balance so that incoming radiation equals outbound radiation, the surface perforce must, has to, is required to warm up until there’s enough additional upwelling longwave to restore the balance.

Now, I’ve mentioned before that this theory is untrue because there are several other ways that the TOA radiation balance can be changed or restored. These include:

    • Increased cloud or surface reflections can reduce the amount of incoming sunlight.

    • Increased absorption of sunlight by the atmospheric aerosols and clouds can lead to greater upwelling longwave.

    • Increases in the number or duration of thunderstorms move additional surface heat into the troposphere, moving it above some of the greenhouse gases, and leading to increased upwelling longwave.

    • A change in the fraction of atmospheric radiation going upwards vs. downwards can lead to increased upwelling radiation.

    • Increased advection (horizontal movement) of heat from the tropics to the polar regions can increase the amount of upwelling longwave radiation

When you think of a top-of-atmosphere (TOA) radiation balance, it’s normal to imagine that all over the earth, the TOA is pretty much in balance everywhere. However, nothing could be further from the truth … here’s the TOA imbalance as shown in the CERES satellite data.

Figure 1. Top-of-atmosphere (TOA) average radiation balance, March 2000 to February 2021. Positive values show an imbalance where there is an excess of incoming solar radiation compared to outgoing longwave (thermal) radiation, and vice-versa regarding negative values.

As you can see, the only place where incoming and outgoing radiation are equal is shown by the black/white lines. In the tropics, there’s much more net incoming solar radiation (after reflections) than outgoing longwave radiation. And outside of that region towards both poles, there’s much more outgoing longwave radiation than incoming solar radiation.

This is the result of the “advection” mentioned above, the polewards horizontal transfer of energy via ocean currents and atmospheric movements. And this is a gigantic movement of energy. It is a constant flow of about 15 petawatts (1015 watts) across the black/white lines above.

How much energy is that? Well, if you put a 1-gigawatt nuclear power plant every three meters along the black/white lines above that circle the earth at about 40°N/S of the Equator … that’s how much energy they’d generate in total.

Or to look at it another way, it’s more than a thousand times the ongoing total primary energy consumption of all the people on the planet.

With that as background, let me return to the question of the TOA balance. Increasing CO2 absorbs more upwelling longwave, leading to less outgoing longwave at the TOA. This makes the TOA balance more positive.

And in theory, increasing surface temperature should increase the amount of outgoing longwave at the TOA. This would make the TOA balance more negative. In short, when the surface temperature goes up, the TOA balance should go down

In considering this, I realized I’d never actually looked at this relationship. Here, again from the CERES dataset, are the two variables in question—surface temperature and TOA imbalance.

Figure 2. Change in surface temperature, March 2000 – February 2021

This is in good agreement with other global surface temperature reconstructions, such as Berkeley Earth and HadCRUT, although each of these global temperature datasets differs slightly from the others.

Next, I looked at the change in the TOA imbalance.

Figure 3. Change in TOA radiation imbalance, March 2000 – February 2021

When I saw that, I said something that sounded very much like “YIKES!!”.


Well, if you recall from above, as temperature goes up, TOA imbalance is supposed to go down … but it’s not. The TOA imbalance not even staying level. It’s going up.

To investigate this further I created a scatterplot of the TOA imbalance versus surface temperature … and here’s that chart.

Figure 4. Scatterplot, top-of-atmosphere (TOA) radiation imbalance versus surface temperature, March 2000 – February 2021

Same problem, only worse—there is NO statistically significant relationship between surface temperature and the TOA radiation imbalance.

Curious … clearly, the conclusion from this has to be that the other factors that affect the TOA balance have much more effect than the change in surface temperature.

To me, this isn’t a surprise. I see the climate system as a giant natural heat engine that is ruled by the Constructal Law discovered by Adrian Bejan. According to the Constructal Law, flow systems far from equilibrium must constantly change and evolve in order to persist … and as a result, as in this case, the simplistic assumptions of modern climate science simply don’t pan out. Here’s Figure 1 of an analysis of the climate by Bejan and Reis entitled “Thermodynamic optimization of global circulation and climate” …

Note how the climate system naturally evolves to have a high-temperature area AH and a low-temperature area AL … compare that to Figure 1 at the top of this post. The Bejan/Reis paper is most fascinating. I cannot recommend it enough to anyone seriously interested in climate. The Constructal Law is the first new law of thermodynamics in over a century, and it applies to a wide variety of natural systems. Further information on the Constructal Law is available at constructal.org, along with an excellent article on the subject in Forbes magazine here.

Further thoughts on the matter gladly accepted …


Como De Costumbre: When you comment please quote the exact words you are referring to. This avoids much of the misunderstandings that plague the intarwebs. I can and am happy to defend my own words. I can’t defend your interpretation of my words.

A Technical Note: Over the 21-year period, the upwelling LW from the surface has increased by ~1.5 W/m2, of which about 1 W/m2 makes it to space without being absorbed by GHGs and redirected back downwards. This should have decreased the TOA imbalance by about 1 W/m2.

And over the same period, the increase in CO2 forcing should have increased the TOA imbalance by about 0.6 W/m2. The net result should have been a 0.4 W/m2 decrease in the TOA imbalance over the period.

Instead, we’ve seen a 0.8 W/m2 increase in the TOA imbalance … which is why I said “YIKES!”.

via Watts Up With That?


December 14, 2021 at 12:24PM

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