Medary.com

I've spent an afternoon reading the July 2008 issue of Physics and Society--the one where, perhaps, the scientific community begins, ever so slowly, to inch away from jumping off of the political and economic cliff which is "anthropogenic global warming."

The paper by Lord Monckton (which, of course, the publication goes out of its way to say is not peer-reviewed) is of great interest, I think.  He raises a number of specific questions regarding the United Nations' IPCC political group's climate publications.  I've taken the liberty of copying the entire Discussion section of Monckton's paper, which you can read in the Read More section below.  I look forward to discussion, refutation, or validation of Monckton's observations (as opposed to arguments from authority focusing on his lack of a relevant Ph.D., that is.)

We have set out and then critically examined a detailed account of the IPCC’s method of evaluating climate sensitivity. We have made explicit the identities, interrelations, and values of the key variables, many of which the IPCC does not explicitly describe or quantify. The IPCC’s method does not provide a secure basis for policy-relevant conclusions. We now summarize some of its defects.

The IPCC’s methodology relies unduly – indeed, almost exclusively – upon numerical analysis, even where the outputs of the models upon which it so heavily relies are manifestly and significantly at variance with theory or observation or both. Modeled projections such as those upon which the IPCC’s entire case rests have long been proven impossible when applied to mathematically-chaotic objects, such as the climate, whose initial state can never be determined to a sufficient precision. For a similar reason, those of the IPCC’s conclusions that are founded on probability distributions in the chaotic climate object are unsafe.

Not one of the key variables necessary to any reliable evaluation of climate sensitivity can be measured empirically. The IPCC’s presentation of its principal conclusions as though they were near-certain is accordingly unjustifiable. We cannot even measure mean global surface temperature anomalies to within a factor of 2; and the IPCC’s reliance upon mean global temperatures, even if they could be correctly evaluated, itself introduces substantial errors in its evaluation of climate sensitivity.

The IPCC overstates the radiative forcing caused by increased CO2 concentration at least threefold because the models upon which it relies have been programmed fundamentally to misunderstand the difference between tropical and extra-tropical climates, and to apply global averages that lead to error.

The IPCC overstates the value of the base climate sensitivity parameter for a similar reason. Indeed, its methodology would in effect repeal the fundamental equation of radiative transfer (Eqn. 18), yielding the impossible result that at every level of the atmosphere ever-smaller forcings would induce ever-greater temperature increases, even in the absence of any temperature feedbacks.

The IPCC overstates temperature feedbacks to such an extent that the sum of the high-end values that it has now, for the first time, quantified would cross the instability threshold in the Bode feedback equation and induce a runaway greenhouse effect that has not occurred even in geological times despite CO2 concentrations almost 20 times today’s, and temperatures up to 7 ºC higher than today’s.

The Bode equation, furthermore, is of questionable utility because it was not designed to model feedbacks in non-linear objects such as the climate. The IPCC’s quantification of temperature feedbacks is, accordingly, inherently unreliable. It may even be that, as Lindzen (2001) and Spencer (2007) have argued, feedbacks are net-negative, though a more cautious assumption has been made in this paper.

It is of no little significance that the IPCC’s value for the coefficient in the CO2 forcing equation depends on only one paper in the literature; that its values for the feedbacks that it believes account for two-thirds of humankind’s effect on global temperatures are likewise taken from only one paper; and that its implicit value of the crucial parameter κ depends upon only two papers, one of which had been written by a lead author of the chapter in question, and neither of which provides any theoretical or empirical justification for a value as high as that which the IPCC adopted.

The IPCC has not drawn on thousands of published, peer-reviewed papers to support its central estimates for the variables from which climate sensitivity is calculated, but on a handful.

On this brief analysis, it seems that no great reliance can be placed upon the IPCC’s central estimates of climate sensitivity, still less on its high-end estimates. The IPCC’s assessments, in their current state, cannot be said to be “policy-relevant”. They provide no justification for taking the very costly and drastic actions advocated in some circles to mitigate “global warming”, which Eqn. (30) suggests will be small (<1 °C at CO2 doubling), harmless, and beneficial.