Skeptics 1, Fanatics 0. That’s the final score.
The corrected mid-range estimate of Charney sensitivity, which is equilibrium sensitivity to doubled CO2 in the air, is less than half of the official mid-range estimates that have prevailed in the past four decades. Transient sensitivity of 1.25 K and Charney sensitivity of 1.45 K are nothing like enough to worry about.
This third article answers some objections raised as a result of the first two pieces. Before I give some definitions, equations and values to provide clarity, let me make it plain that my approach is to accept – for the sake of argument only – that everything in official climatology is true except where we have discovered errors. By this acceptance solum ad argumentum, we minimize the scope for futile objections that avoid the main point, and we focus the discussion on the grave errors we have found.
Definitions
All definitions except that of temperature feedback are mainstream. I am including them in the hope of forestalling comments to the effect that there is no such thing as the greenhouse effect, or that temperatures (whether entire or delta) cannot induce feedbacks. If you are already well versed in climatology, as most readers here are, skip this section except for the definition of feedback, where climatology is at odds with mainstream feedback theory.
Greenhouse gases possess at least three atoms in their molecules and are thus capable of possessing or, under appropriate conditions, acquiring a dipole moment that causes them to oscillate in one of their vibrational modes and thus to emit heat.
Carbon dioxide (CO2), being symmetrical, does not possess a dipole moment, but acquires one in its bending vibrational mode on interacting with a near-infrared photon. To use Professor Essex’s excellent analogy, when a greenhouse gas meets a photon of the right wavelength it is turned on like a radiator, whereupon some warming must by definition occur.
The non-condensing greenhouse gases exclude water vapor.
Water vapor, the most significant greenhouse gas by quantity, is a condensing gas. All relevant changes in its atmospheric burden are treated as temperature feedbacks. Its atmospheric burden is thought to increase by 7% per Kelvin of warming in accordance with the Clausius-Clapeyron relation (Wentz 2007).
Emission temperature would obtain at the Earth’s surface if there were no non-condensing greenhouse gases or feedbacks present. Emission temperature is a function of insolation, albedo and emissivity (assumed to be unity), and of nothing else. As non-condensing greenhouse gases and feedbacks warm the atmosphere, the altitude at which the emission temperature obtains rises.
Radiative forcing (in W m–2) is an exogenous perturbation in the net (down minus up) radiative flux density at the top of the atmosphere. Forcings become warmings via –
The Planck sensitivity parameter (in K W–1 m