Matt Ridley on the IPCC

Matt Ridley: The Perils Of Confirmation Bias. Read it at GWPF [updated at 12.25pm to prevent confusion]

The modus operandi of the Intergovernmental Panel on Climate Change (IPPC) has been to accumulate evidence to champion rather than challenge a hypothesis, namely that rising carbon dioxide levels will in future cause dangerous climate change.

A good example is the IPCC’s claim that only models that incorporate high-sensitivity carbon dioxide-induced warming countered by aerosol induced cooling can match (or “hindcast”) the recent upward progress of global average temperatures. The problem with this is that different models use different values of assumed cooling from aerosols. That is to say, the cooling effect of aerosols has been picked so that it fills the gap between observed and expected warming. The modellers are therefore in effect saying: we observe warming of X, we predicted warming of X+5, so there must have been cooling of 5, therefore our prediction is correct.

Read more here

http://www.thegwpf.org/matt-ridley-the-perils-of-confirmation-bias/

Shub and the IPCC renewables report

Shub Niggurath has been looking at the nitty-gritty of the IPCC's renewables report and, in AGW parlance, "it's worse than we thought".

...the situation is analogous to a biological experiment where some of the control cases also appear in the study group or the use of a new experimental methodology where a fraction of the target subjects are themselves used in the training set. An even more accurate analogy would be like attempting to compare two clinical studies: the first one, where a small number of patients with good outcomes are selected and the study examines patient records retrospectively to see that such patients received quality healthcare at substantial healthcare costs, and a second prospective study which aims to attain the same for all included patients, with the exact same good outcomes operating as constraints. Healthcare costs (akin to CO2) in the second study would necessarily be high! The result is circularity of inference, and the root of the problem lies in the cross-inheritance of input parameters between scenarios of fundamentally opposite types.