IPCC reports, and particularly their Summaries for Policy Makers (SPM), are noted for their bias in support of the political goal of control of fossil fuels in order to fight alleged anthropogenic global warming AGW).
The most blatant example is the Second Assessment Report (SAR), completed in 1995 and published in 1996. Its SPM contains the memorable phrase “The balance of evidence suggests a discernible human influence on global climate.”
This ambiguous phrase conveys a mental picture of climate scientists, preferably with gray beards, sitting around a table judging both human and natural influences, looking at published scientific research, and carefully weighing their decision. Nothing of the sort has ever happened. The IPCC has consistently ignored the real natural influences on climate change and has focused almost entirely on human causes, especially GH gases -- and more especially on carbon dioxide, which is linked to industrial activities and therefore bad almost by definition.
How then does the IPCC-SAR arrive at this “balance?” It was done by carefully removing references to any doubt that human influences are the major or almost exclusive cause of warming. I will quote here from the WSJ (August 13,1996) article, written by the late Professor Frederick Seitz. He compared the draft approved by the authors of IPCC-SAR Chapter 8 (Detection and Attribution) and the final printed text. He noted that key phrases had been deleted from the approved draft before printing.
This IPCC report, like all others, is held in such high regard largely because it has been peer-reviewed. That is, it has been read, discussed, modified and approved by an international body of experts. These scientists have laid their reputations on the line. But this report is not what it appears to be--it is not the version that was approved by the contributing scientists listed on the title page. In my more than 60 years as a member of the American scientific community, including service as president of both the National Academy of Sciences and the American Physical Society, I have never witnessed a more disturbing corruption of the peer-review process than the events that led to this IPCC report.
A comparison between the report approved by the contributing scientists and the published version reveals that key changes were made after the scientists had met and accepted what they thought was the final peer-reviewed version. The scientists were assuming that the IPCC would obey the IPCC Rules--a body of regulations that is supposed to govern the panel's actions. Nothing in the IPCC Rules permits anyone to change a scientific report after it has been accepted by the panel of scientific contributors and the full IPCC.
The participating scientists accepted "The Science of Climate Change" in Madrid last November; the full IPCC accepted it the following month in Rome. But more than 15 sections in Chapter 8 of the report--the key chapter setting out the scientific evidence for and against a human influence over climate--were changed or deleted after the scientists charged with examining this question had accepted the supposedly final text.
Few of these changes were merely cosmetic; nearly all worked to remove hints of the skepticism with which many scientists regard claims that human activities are having a major impact on climate in general and on global warming in particular.
The following passages are examples of those included in the approved report but deleted from the supposedly peer-reviewed published version:
“None of the studies cited above has shown clear evidence that we can attribute the observed [climate] changes to the specific cause of increases in greenhouse gases."
* "No study to date has positively attributed all or part [of the climate change observed to date] to anthropogenic [man-made] causes."
* "Any claims of positive detection of significant climate change are likely to remain controversial until uncertainties in the total natural variability of the climate system are reduced."
The reviewing scientists used this original language to keep themselves and the IPCC honest. I am in no position to know who made the major changes in Chapter 8; but the report's lead author, Benjamin D. Santer, must presumably take the major responsibility.
IPCC reports are often called the "consensus" view. If they lead to carbon taxes and restraints on economic growth, they will have a major and almost certainly destructive impact on the economies of the world. Whatever the intent was of those who made these significant changes, their effect is to deceive policy makers and the public into believing that the scientific evidence shows human activities are causing global warming.
If the IPCC is incapable of following its most basic procedures, it would be best to abandon the entire IPCC process, or at least that part that is concerned with the scientific evidence on climate change, and look for more reliable sources of advice to governments on this important question.
In addition to these text changes there are also two key graphs that were doctored in order to convey the impression that anthropogenic influences are dominant.
You may recall that this dishonest 1996 IPCC report played a key role in the political deliberations that led to the 1997 Kyoto Protocol. The persons responsible for making these alterations bear a heavy responsibility for misleading the Kyoto conference and for the subsequent economic damage.
