Guest post by Rud Istvan
A few days ago, I posted another Lindzen Bode ECS reconciliation. It should have been controversial, stimulating many comments because of the divergence to higher climate models and also to Monckton’s often here posted much lower estimates. It was only mildly so, most about my penetration f/(1-f) versus Bode 1/(1-f) one phrase in one sentence goof, which did not affect the post’s conclusions since it only used Lindzen’s correct curve posted here decade ago.
Recently, Dr. Wentworth posted a ‘mathematical proof ‘ that the GHE must exist, even though misnamed (because real greenhouses retard local convective cooling, while greenhouse gases retard radiative cooling to space). This misnomer is no different than the equivalent ocean acidification misnomer we are also forced to live with in popular discourse. Warmunists long ago picked their definitional terms of debate, and WUWT skeptics are mostly stuck with them. Definitional quibbling may satisfy some, but probably isn’t an effective tactic.
I was very surprised at the number of negative comments at WUWT (now well over 600) to this rigorous post with an obviously verifiable conclusion. They spanned the gamut from epistemological (really a proof, or something else?), to the old Venus/Mars ‘analogies’, to the new ignores convection (true, but convention only moves heat around in the atmosphere; it cannot not make it go away like radiation to space does), to even the very old gravitational density heating canard (ignoring that since Earths atmosphere got densified (aka ‘pumped up’) by gravitational consolidation about 4.5 billions years ago, unlike a newly pressurized bicycle tire it has had a LONG time to cool back down). I chose not to name names; this possible guest post is only a general rebuke.
The surprisingly controversial post’s conclusion is also easily personally verified by simple observation. Tyndall proved in 1859 that both CO2 and H2O were GHG, while N2 and O2 are not. So a personal experiment can be conduced in any desert (mine was a summer day in the Mohave outside Palm Springs during a boring conference). The dry desert heats up a lot from insolation during the day, and cools down a lot at night thanks to desert low specific humidity, so not much GHG except well-mixed CO2, and therefore not much GHE at night. Burrr!
There are only two even semi-rational (but still erroneous) arguments why the CO2 GHE might not exist despite Tyndall’s experimental GHG evidence.
- The CO2 window overlaps the H2O window. Note, this does not say the GHE does not exist; only that CO2 ‘cannot’ be a contributor so IPCC is wrong. This assertion is frequently found on the internet in graphical form, but erroneously portrayed for two reasons (both errors are present in negative WUWT comments). The usual stuff omits radiation intensity; and while some windows do overlap, others don’t. Fine IR scale matters. The actual overlaps/windows plus their radiative intensities were provided in essay Sensitive Uncertainty in ebook Blowing Smoke. The essay’s illustration is reproduced below. Forgive the unfortunate insolation extra zero K typo, which I just caught myself. Absorption is a metric of the degree of a gas GHE effect at some frequency (wavelength), from 0 (none) to 100% (full).
Reality has to do with radiation intensity and window ‘shoulders’.
- GHG are saturated, so can have not have any further effect. This misunderstands saturation, since it depends on the effective radiative level (ERL). As CO2 increases, the ERL rises unconstrained, since CO2 is unaffected by the lapse rate, while H2O is and so decreases. This also reduces their mid troposphere’s overlapping radiative windows. More CO2 raises the ERL. As Callendar’s 1938 curve reproduced below (from Climate Audit) first showed, the GHE never saturates.
Also note that over the region of Callendar’s curve of present interest, the curve is approximately linear, which is why in my comment to UAH’s most recent report, I did not bother to make the log correction correctly suggested in subsequent comments to my back of the envelope implied 1.7C ECS fraction that Roy’s new update nicely implicitly brackets. ‘Good enough for government work’.
To summarize without any math, the GHE exists. It experimentally must, and easily provably does. The GHE issues are how much when (ECS), not if. Any ‘skeptical’ arguments to the contrary are fairly easily rebutted, as done here.