an incorrect claim that 55% of the Netherlands is below sea level. (on p303 Plimer says
In addition, an interagency report into the IPCC processes and procedures has identified a need for greater consistency in the terminology used for uncertainty across the three IPCC working groups.
Ian Plimer’s claim that the human influence on climate can be ignored, relative to natural vari- ations seems to rest on three main strands of argument:
a: the extent of natural variability is larger than considered in ‘mainstream’ analyses;
b: the effects of changes in radiative forcing are smaller than values used in ‘mainstream’ analyses;
c: the IPCC uses a range of misrepresentations to conceal points a and b.
The most obvious point to note is that if there was a valid case to be made for any of these claims, then there would have been no need for Plimer to resort to systematic misrepresentation.
a: The extent of natural variability is being misrepresented, particularly through an exaggerated emphasis on the Medieval Warm Period (MWP). The cited references for large-scale Medieval warming fail to support the claim and in several of these cases seem not to mention Medieval warming at all — [items 21, 23, 123]. The one reference that seems most relevant to global-scale changes (at least over land) is the paper on the borehole data [footnote 256]. The quote from this paper is selective and inaccurate [see item 24]. The main results of the paper indicate MWP temperatures higher by 0.1 to 0.5◦C, rather than the 2 to 3◦C claimed by Plimer [item 24].
b: The effect of radiative forcing is being misrepresented by repeated claims of a climate sen- sitivity of 0.5◦C [items 69, 73, 120] even when Plimer’s own examples show climate sensitivities of 1.5◦C to 1.6◦C [item 104], his denial of an effect beyond 400 ppm [items 74, 75] even when he acknowledges the logarithmic relation [page 338] and presents a graph [figure 50] consistent with that relation [item 75].
The human contribution to changes in the Earth’s radiation balance are extensively mis- represented through misrepresentation of CO2 measurements and misrepresentation of carbon exchanges.
c: For the IPCC there is extensive misrepresentation of:
the content of the IPCC reports [items 10, 11, 29, 32, 93, 97, 100, 109, 110, 111, 118];
the operation of the IPCC assessment process and the authorship of reports [items 150,
the characteristics of climate models that form the basis of some of the science pre-
sented in the IPCC reports [items 49, 68, 121].