Guest Post by Willis Eschenbach
In this post, I will both provide additional data, fix errors and claim in my post called Where is the top of the atmosphere?. Let me start by recapitulating the main point, which is the theory of why an increase in CO2 must lead to surface warming.
• The amount of CO2 in the atmosphere and other greenhouse gases (methane, CFCs, etc.) is increasing.
• This absorbs more of the longer-wave radiation, resulting in peak-atmospheric (TOA) unbalanced radiation. This is the TOA balance between incident sunlight (after some sunlight is reflected back into space) and outgoing long wave radiation (OLR) from the surface and atmosphere.
• To restore balance so that the incoming solar radiation equals the outgoing long-wave radiation (OLR), the surface force must heat up until enough long-wave lift is present to restore balance.
In my last article, I showed what I believe is the relationship between CERES and OLR surface temperatures. Here is that image:
Figure 1. Scatter plot, monthly top-atmosphere emission (TOA LW) versus surface temperature. Seasonal variations were removed from both data sets
Now, I mentioned above that I want to fix the errors and complaints in my previous post. The claim is that although the change in the tropospheric OLR from the CO2 doubling indicated by MODTRAN is about 3.7 W/m2, the change at the top of the atmosphere (TOA) is much smaller.
However, since then I have found an article titled “Force four times CO2 radiation” that says:
Note that the coercion and throttling in this paper are analyzed using radiative flux at TOA instead of temperature. However, it can be shown that after the stratosphere equilibrates, the adjustment forces in the stratosphere are identical at the two levels.
Unfortunately, they neglect to refer only to how or where “It can be displayed”. And I see no reason to assume that is true – why is the high-level long-wave radiation the same, both somewhere in the upper middle of the atmosphere and also at the top of the atmosphere? That would assume that the stratosphere does not contribute in any way to the OLR… ?? Seems doubtful.
But there is a very cautious view by which I would say that increase climate sensitivity, for the sake of this discussion I will assume that they are correct and that the OLR above the atmosphere (TOA) is reduced by 3.7 W/m2 from the doubling of CO2, the same as in temperature.
So that’s the claim… what about the fault?
Well, my mistake was that I used actual TOA OLR figures to calculate the relationship between surface temperature and OLR. But assuming that the prevailing theory is correct, those OLR values have been reduced by the effects of greenhouse gases. So, to get a real relationship between temperature and OLR, we need to add up the reduction in OLR due to greenhouse gases.
To get a more precise answer from a longer recorded time period, this time I used Berkeley Earth surface temperature data and NOAA OLR data. This gives us about twice the data we have from CERES satellite observations. Figure 2 shows that result.
Figure 2. Scatterplot, NOAA OLR adjusted for well-mixed greenhouse gases (WMGHG) relative to Berkeley Earth’s surface temperature. Seasonal variations were removed from both data sets
As expected, adjusting the OLR data to include the effect of WMGHGs increased the trend of the OLR relative to surface temperature.
When examining the Berkeley/NOAA data, I only take part of it on top of the CERES data, and I plot both. As you can see, the agreement between the two is better than what is usually found between different climate datasets.
Figure 3. Comparison of Berkeley/NOAA and CERES values. Seasonal variations were removed from both data sets
So… according to Figure 2, to offset the doubling of CO2, which would reduce the TOA OLR perhaps 3.7 W/m2, the temperature must increase by 3.7 W/m2 divided by 4.2 W/m2 per °C , that is, 0.9°C for each CO2 doubling.
Is this a “climate equilibrium sensitivity” in the long term rather than a “climate transient response” in the short term? I say yes because it doesn’t depend on the time it takes for the temperature to rise. Whether the temperature increases by 0.9°C in a month, a year or a decade, the above data shows that it will increase the OLR by 3.7 W/m2.
And that’s all I have for you for today.
Best regards to everyone,
w.
AS ALWAYS: I can defend and explain my words and I am happy to do so. I cannot defend or explain how you interpret my words. So when you comment, please QUOTE EXACT WORDS that you are discussing. This avoids endless misunderstandings.
MATH: As discussed in my previous post, Where is the top of the atmosphere?I used Deming regression instead of Least Normal Squares regression because of the presence of significant uncertainty in the x-axis of the graph.
DATA:
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