Update: see further discussion here NOAA has a webpage on radiative forcing here, which includes a list of equations relating GHG concentrations to radiative forcing, substantially identical to the expressions in TAR. Below is a figure showing, on the left, the graphic at NOAA illustrating their calculation and, on the right, my emulation of this […]
In the various disputes over Hansen et al 1988, Roger Pielke Jr and NASA apologist Eli Rabett (who has been said to be occasional NASA contractor Josh Halpern) have each attempted to disentangle the forcing projections implied by Hansen et al 1988 – Pielke here and Rabett here for CO2 and here for other gases. […]
Over the last week or so, I’ve reported on my efforts to locate the provenance of the functional forms for the relationship between levels of CO2 and other greenhouse gases and temperature. Lubo has also chipped in on the topic from a different perspective proposing a derivation of a log formula from first principles. We’ve […]
Reader DAV raised the following interesting question: The strange thing about 6..3.5 Simplified Equations that gets me is why should CO2, CH4 and N2O have different equational forms? And what would be the physical basis for raising something to the 0.75 or 1.52 power? The whole thing looks ad hoc as if someone was insistently […]
Yesterday I collated IPCC AR3 and AR4 “expositions” of the enhanced greenhouse effect, observing that, in my opinion, they were so baby food as to be essentially useless to a scientist from another discipline. Today I’m going to drill a little deeper in the expositions, going to a 1995 journal comment by Houghton and to […]
One of the fundamental questions for someone interested in the impact of doubled CO2 is exactly how (1) the greenhouse effect works; and (2) how the “enhanced” greenhouse effect works. AR4 FAQ 3.1 poses the question: I’m going to show their answer to this question in full because the answer does not rise about a […]
Chapter 1 of AR4 has some surprisingly interesting comments about models that, to the extent that the points are disclosed in the body chapters, are disclosed so opaquely that they would be undecipherable to anyone other than a few. Here are some interesting comments about flux adjustment – an issue that must surely raise civilian […]
In our review of IPCC AR1 (1990) on radiative forcing, I noted that the logarithmic relationship and 4 wm-2 values were attributed to: Hansen et al (1988), which in turn cited Lacis et al 1981; and Wigley (1987) which is not presently available to me (or to Wigley himself) and appears not to have been […]
AR4 (chapter 1 on the History of Climate Science) contains the remarkable statement: The strong effect of cloud processes on climate model sensitivities to greenhouse gases was emphasized further through a now-classic set of General Circulation Model (GCM) experiments, carried out by Senior and Mitchell (1993). They produced global average surface temperature changes (due to […]
As an innocent bystander to the climate debates a couple of years ago, I presumed that IPCC would provide a clear exposition of how doubled CO2 actually leads to 2.5-3 deg C. The exposition might involve considerable detail on infra-red radiation since that’s relevant to the problem, but I presumed that they would provide a […]
