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RE: [cdn-nucl-l] The tragedy of science; Climate Change and Nuclear Energy
Jerry Cuttler and Jeremy Whitlock wrote:
From: firstname.lastname@example.org.McMaster.CA on behalf of Whitlock, Jeremy
Sent: Sat 3/24/2007 11:54 AM
To: Canadian Nuclear Discussion List
Subject: RE: [cdn-nucl-l] The tragedy of science; Climate Change and Nuclear Energy
> Does the hypothesis (humans are causing global warming) pass the
> many scientific tests that have been presented?
I think the IPCC said it best in its 1996 draft report:
"None of the studies cited above has shown clear evidence that we can
attribute the observed climate changes to increases in greenhouse gases."
"No study to date has positively attributed all or part of the climate
change to man-made causes"
Unfortunately these were two of the statements deleted from the final text,
in the name of consensus.
Jeremy's observation about the IPCC 1996 draft report betrays a lack of knowledge about how the IPCC goes about writing and reviewing its reports.
Each section of the report will have (a) Lead Author(s), who will parcel out the drafting of specific subsections to contributing authors. The contributing authors will produce drafts of their section and an overall draft will be produced from the pieces by the Lead Author(s). Up till this point, everything has been done by working climates scientists with expertise specific to the (sub)sections they are responsible for. The draft is put out for comment by a group of climate-scientist reviewers and by the immediate world, that is, by anyone who has expressed interest in reviewing and commenting the draft. Some of the registered commentors may be non-climate-scientists. I registered as a commenter on the 2000 draft that eventually became Volume 1 (The Scientific Basis) of the 2001 Third Assessment Report. I can't remember whether I commented, but lots of people did. Resolutions are proposed by the original authors for all comments. At this point, the authors and climate-scientist reviewers meet to review the comments and the proposed resolutions and to make changes to the draft, as needed. A similar process is used for the overall Volume 1 Technical Summary (which ran to 50 pages in the TAR) and for the Summary for Policy Makers (around 20 pages in the TAR and in this year's FAR). The only significant involvement of non-climate scientists is in the final review of the Summary for Policy Makers, where the scientist authors and representatives of the 150 or so governments that are involved in the IPCC process get together in a several-day meeting to beat out the final draft of the SPM.
As this process has worked in the past, the deletion Jeremy describes would have occurred during the scientist review, because changes at the stage of the governmental review of the SPM have almost all involved softening of the scientific assertions. Typically these changes have been required by Saudi Arabia or China or, in recent years, by the US, countries interested in downplaying the evidence for anthropogenic global warming. In the current issue (April 2007) of Scientific American, David Biello writes that Saudi Arabia and China insisted on the removal from the FAR SPM of a sentence that stated that the impact of human activity on the earth's heat budget exceeds that of the sun by a factor of five. Biello quotes the Lead Author Piers Forster of the University of Leeds: "The difference is really a factor of 10".
What were the bottom lines in the 1996 SAR, the 2001 TAR, and in the current FAR Summary for Policy Makers?
In the 1996 SAR:
"the balance of evidence suggests a discernible human influence of global climate"
In the 2001 TAR:
"The warming over the past 100 is very unlikely to be due to internal variability alone, as estimated by current models." and "There is a wide range of evidence of qualitative consistencies between observed climate changes and model responses to anthropogenic forcing." and "All simulations with greenhouse gases and sulphate aerosols that have been used in detection studies have found that a significant anthropogenic contribution is required to account for surface and tropospheric trends over at least the last 30 years."
In the 2007 FAR SPM:
"The understanding of anthropogenic warming and cooling influence on climate has improved since the Third Assessment Report (TAR), leading to a very high confidence  that the globally averaged net effect of human activities since 1750 has been one of warming, with a radiative forcing of +1.6 [+0.6 to +2.4] Watts per meter squared. (see Figure SPM-2)"
"Warming of the climate system is unequivocal, as is now evident from observations of increases in global average air and ocean temperatures, widespread melting of snow and ice, and rising global average sea level (see Figure SPM-3)."
"Most of the observed increase in globally averaged temperatures since the mid-20th century is very likely due to the observed increase in anthropogenic greenhouse gas concentrations . This is an advance since the TAR's conclusion that 'most of the ovserved warming over the last 50 years is likely to have been due to the increase in greenhouse gas concentrations'. Discernible human influence now extend to other aspects of climate, including ocean warming, continental-average temperatures, temperature extremes and wind patterns (see Figure SPM-4 and Table SPM-2)."
The TAR and the FAR explicitly define the terms "likely", "very likely", and "very high confidence", etc.
All four volumes of the TAR and the FAR SPM are available online for download (as PDFs) from the website of the IPCC at www.ipcc.ch . The TAR Technical Summary and Spencer Weart's book, History of Global Warming, (both available for download on the Internet) are good places to start for technically-educated non-climate-scientists interested in learning about climate science and the current state of knowledge. Those uninterested can get their ideological ears scratched by the Wall Street Journal editorial board and Rush.
Pacific Northwest National Laboratory
These comments are mine and have not been reviewed and/or approved by my management or by the U.S. Department of Energy.