Changes

{{Show badges| Climate change}}The [[Fraser Institute]]'s '''Independent Summary for Policymakers''' (ISPM) was published on Feb. 5, 2007, just after the release of the [[Intergovernmental Panel on Climate Change]] (IPCC) Summary for Policy Makers, part of the Fourth Assessment Report on Climate Change (AR4). Economist and Fraser Institute Senior Fellow [[Ross McKitrick]] served as co-ordinator of the ISPM. The Fraser Institute's [http://www.fraserinstitute.org/commerce.web/publication_details.aspx?pubID=3184 ISPM overview page] contains an executive summary as well as a link to [http://www.fraserinstitute.org/COMMERCE.WEB/product_files/Independent%20Summary5.pdf download the current version of the ISPM]. The [http://www.fraserinstitute.org/COMMERCE.WEB/product_files/Independent%20Summary2.pdf original version of the ISPM] is also available (see section on errors and discrepancies below). For comparison, the various chapters of the IPCC WG1 AR4 report are available at the [http://ipcc-wg1.ucar.edu/wg1/wg1-report.html IPCC AR4 download page]. The full citation of this IPCC report is: Climate Change 2007: The Physical Science Basis. Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change [Solomon, S., D. Qin, M. Manning, Z. Chen, M. Marquis, K.B. Averyt, M. Tignor and H.L. Miller (eds.)]. Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA.

The ISPM also states: "Adjusting T2 data to remove an estimated contribution from the stratosphere yields tropospheric trend coefficients ranging from about 0.12 oC to 0.19 oC per decade, '''depending on the method.'''" [ISPM 2.1c] In fact, But the method employed makes little difference. The difference between UAH and RSS results is almost entirely appears to be mainly due to the different T2 differing tropospheric data filtering and adjustments calibrations '''priorindependent''' to of adjustments to remove spurious stratospheric cooling, as seen in ; a comparison of the "Troposphere" T2 and TMT (RSS stratospheric removal methodmid-troposphere) trends also show similar differences in trends between the UAH and "Lower troposphere" (UAH removal method) panelsRSS. [AR4 Fig. 3.18] For example, RSS adjusted trend is 0.19 if the RSS method is employed, and 0.18 if the UAH method is employed.

However, this would appear to be an imprecise summary of the NRC recommendations. The NRC stated that "[U]sing proxies sensitive to hydrologic variables ... should be done only if the proxy–temperature relationship has climatologic justification." (NRC, p. 116-7) It should be clarified as well that the NRC did not recommend against the all use of bristlecones and foxtails as proxies, but rather stated that "'''strip-bark samples'''" of these proxies should be avoided [emphasus emphasis added].

The ISPM goes on: "However, none of the IPCC reconstructions for the past millennium observe the National Research Council recommendations."There is no citation or detail given for this assertion, but it is important to note that this finding is not contained in the NRC report itself (which did review all of the reconstructions cited in the IPCC). Indeed, in a live online discussion of the "hockey-stick" controversy, Gerald North, chairman of the NRC report panel stated: "I feel certain that the most recent studies by Cook, d'Arrigo and others do take this [strip-bark problem] into account." [http://chronicle.com/live/2006/09/hockey_stick/] ===Attribution studies===According to the IPCC, attribution of observed climate change to anthropogenic forcings such as greenhouse gases can be established through the use of computer models. [IPCC 9, ISPM 6] The ISPM summary states: "These attribution studies do not take into account ... potentially important influences like aerosols, solar activity, and land use changes." This would appear to be an error, as even the ISPM itself states: "Studies have concentrated on what are believed to be the most important forcings: greenhouse gases, direct solar effects, some aerosols and volcanism."  The ISPM generalizes as follows: "Attribution studies to date do not take into account all known sources of possible influence on the climate." [ISPM 6.3c] This is true of most, but certainly not all, of the cited attribution studies, as even the ISPM admits that some studies do take into account forcings such as black carbon and land use. Moreover these studies "continue to detect a significant anthropogenic influence on 20th century temperature changes." [ISPM 6.3c; see also AR4 9.4.1.8 and Table S9.1]

[[categoryCategory:Global warmingClimate change]]