CO2 Climate Sensitivity Vs. Reality

Anyone who has followed the climate debates on the internet knows that even most "skeptics" of runaway global warming (and all of those who ever make the news or have a large audience on their blogs) accept the consensus "greenhouse effect" and the idea of a "CO2 climate sensitivity", or theoretically expected global mean surface temperature (GMST) increase with increasing atmospheric carbon dioxide (CO2--due, everyone is brainwashed to believe, in increasing fossil fuel consumption by man). Anthony Watts has posted yet another article by one of his fellow-believers, arguing for a significant value of the CO2 climate sensitivity (albeit smaller than that claimed by the alarmist climate scientists). The following is my response, to any who are still capable of thinking for themselves on the subject, and who want definitive, quantitative proof of the truth of the matter.

Anyone who wants to keep worrying about the "CO2 climate sensitivity" needs to explain why, in the Venus/Earth temperature comparison I performed well over 2 years ago, there is none at all: Venus has 96.5% CO2 to Earth's less than .04%, yet the Venus/Earth temperature ratio is a constant due entirely and precisely to the ratio of their distances from the Sun and nothing else (no "greenhouse effect" contribution, no "difference in planetary albedo" contribution--no anything but the difference in the solar distance).

The precision with which the solar distance, by itself, explains the Venus/Earth temperature ratio--at points of equal pressure, over the range of Earth tropospheric pressures--is nothing short of amazing, in the present tattered intellectual climate, in which the greenhouse effect is adamantly, vehemently claimed to be "settled science", and even most "skeptics" smugly argue for SOME CO2 climate sensitivity. But the Venus/Earth comparison says that smug certainty is a lie, and there simply is no greenhouse effect, of increasing temperature with increasing atmospheric carbon dioxide, AT ALL.

If one is dense enough, after studying my Venus/Earth analysis, to demand what that analysis shows the CO2 climate sensitivity to be, here is what it says:

First, for over half of the range of Earth tropospheric pressures (between ~650 - 250 mb), the Venus temperature is COOLER, by about 5°K, than is predicted from the solar distances alone. But as indicated in my original analysis, in this pressure range lies the thick planetary cloud cover of Venus. Below that range--between 1,000 and 700 mb--the temperature ratio is essentially just that predicted from the solar distances alone; above the cloud layer as well (at 200 mb), the ratio again comes back to very near the "solar distances only" prediction, though not quite all the way (the Venus temperature there is only ~1.7K cooler than so predicted)

The best estimate of the climate sensitivity to changes in CO2 alone, then, is made with those points below the Venus cloud layer. For the 4 points in that pressure range, in my original analysis, the Venus/Earth temperature ratio varies between 1.172 (at 800 mb) and 1.178 (at 1,000 mb), with the average being 1.175.

(The uncertainty in that measured ratio is just the uncertainty in the Venus temperature (1.4K) divided by the corresponding Earth temperature (average 278.3K, for those 4 points), or +/-.005.)

Now 1.175 is just .001 less than the 1.176 predicted by the solar distances alone, and since that error is much less than the +/- .005 uncertainty, it should be immediately obvious that there is no greenhouse effect, without even bothering to calculate a "CO2 climate sensitivity". But let's do so anyway. That .001 "error" in the temperature ratio gives a possible error of only .001 x T_earth, or about -.3K, from the Venus temperature predicted by solar distances alone (that is, using 1.176 for the ratio). If one assumes that -.3K difference is due entirely to the "CO2 greenhouse effect", then the maximum CO2 climate sensitivity (in degrees K per doubling of CO2) is -.3K divided by the number of doublings, between ~353 ppm on Earth (in October 1991, when the Venus data was obtained) and 965,000 ppm (96.5%) on Venus--which is 11.4 doublings of CO2, so that -.3K/11.4 = -.026K/doubling of CO2, or about -.03K/doubling (a slight negative number, note), for the CO2 sensitivity.

But with an uncertainty of +/- 1.4K in the Venus temperature (see my original analysis), the uncertainty in the CO2 climate sensitivity is +/- 1.4/11.4 = .12K/doubling.

So my Venus/Earth comparison demands that the CO2 climate sensitivity must be less than

( -.026 +/- .12) K/doubling

and since the indicated sensitivity is much smaller than the uncertainty, the CO2 climate sensitivity revealed by my Venus/Earth comparison must be reported as

essentially zero (0),

...which is just a precise quantitative statement of the fact that has been obvious all along, that the Venus/Earth comparison shows there is NO greenhouse effect, period. Only solar distance counts in the detailed comparison of these two vastly different planet-plus-atmosphere systems. And the physical reason is because both atmospheres are fundamentally and globally warmed in precisely the same way: by direct absorption of the same physical fraction of the incident solar energy (and NOT from the planetary surface, as almost everyone--and certainly every mis-titled "expert"--believes is the case on Earth).

Added Note: In the above, there are in fact three different, but equivalent, quantitative statements to demonstrate that there is no greenhouse effect of increasing temperature with increasing CO2:

1) The error between measured Venus temperature and that predicted from Earth's Standard Atmosphere and the smaller solar distance of Venus = (-0.3 +/- 1.4)K,

2) The error between measured and predicted Venus/Earth temperature ratio = -.001 +/- .005,

3) The possible size of the CO2 climate sensitivity = zero (-.026 +/- .12)(K/doubling of CO2)

In all three quantitative statements, the (+/-) uncertainty is about 5 times the error, indicating the error is entirely negligible

Just Apologize, Climate Scientists

The wattsupwiththat site has yet another go at "constraining" the carbon dioxide "climate sensitivity", from a renowned member of the English peerage, to which I have responded:

The basic fact is, the global temperature record over the last century and more -- and many "skeptics" have pointed this out, with graphs -- shows global cooling from about 1880 to 1910, warming from about 1910 to 1940, cooling again from 1940 to 197(5), and warming again from 1975 to near 2000 (and now cooling again). There is even a well-known theory about this (involving multidecadal ocean oscillations, on top of an apparent recovery from the so-called Little Ice Age, since the 17th century). A good number of researchers have pointed out that the CO2 atmospheric concentration has gone up throughout that period, and have reasonably claimed that therefore CO2 cannot be blamed for the up and down temperature record. Believers -- and that is all they are, believers -- only muddy the debate with their attempts to distinguish between "forcings" and "feedbacks", in that up and down temperature situation.

The period 1960 to 2008, considered by Christopher Monckton here, is from the middle of a cooling period to a little past the end of a warming period, so temperatures have gone both up and down in that period, while CO2 has definitely continued to rise. Does he think this is an optimal test of CO2 "forcing"? In this, he is ignoring a basic fact in the longer temperature record that speaks against any CO2-driven "climate sensitivity" at all, and apparently finds what so many others have pointed out, simply from looking at those wider up and down periods: That the temperature is NOT driven by CO2, period. I think they did by simple observation better than Mr. Monckton has done here with the sorts of naive equations (dT = λ dF) favored by the incompetent consensus scientists. "Lukewarm" believers like him curry (whoa -- Judith Curry is another one) to the consensus theory, instead of decisively breaking with it, as they should.

If you ignore the simple evidence of the up and down temperature record vs. the monotonically rising CO2 -- solely in order to maintain there is, there MUST BE, a "greenhouse effect", of increasing temperature with increasing atmospheric CO2 -- then you are all too likely, in your fevered belief in that dogma, to dismiss any claims of definitive disproof of that effect. How could such disproof have been missed, by all of climate science, all these years? If, on the other hand, you don't ignore the ample, indeed overwhelming and simple, evidence just noted, against the greenhouse effect, put forward time and time again, then you probably already know by now that there is such definitive evidence. The only trouble is, you will have to admit that climate scientists have been, and stubbornly continue to be, fundamentally deluded by their (clearly) false theories, and that there is therefore -- and regretfully, considering the attention of the world is focused upon it -- no competent climate science in the world today.

We all make mistakes, even embarrassing ones like this one of mine. But people need to start learning from their mistakes, rather than stubbornly passing them down to the next generation. There is no greenhouse effect, of increasing temperature with increasing CO2.