IPCC: the dirty tricks climate scientists faced in three decades since first report
Published: August 27, 2020 6.57am EDT

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Shortly afterwards the US delegation "tabled a catalogue of attempted emasculations” of the text. Along with the Saudi and Soviet delegations, representatives of the richest and most powerful country in the world “chipped away at the draft, watering down the sense of alarm in the wording, beefing up the aura of uncertainty”.

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The accumulation of carbon dioxide in the atmosphere, caused primarily by the burning of fossil fuels, had been worrying scientists since the 1970s. The discovery of the “ozone hole” above Antarctica had given atmospheric scientists enormous credibility and clout among the public, and an international treaty banning chlorofluorocarbons, the chemicals causing the problem, was swiftly signed.

The Reagan White House worried that a treaty on CO₂ might happen as quickly, and set about ensuring the official scientific advice guiding leaders at the negotiations was under at least partial control. So emerged the intergovernmental – rather than international – panel on climate change, in 1988.

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Some scientists, including Columbia University professor James Hansen, argue that the agonising efforts of scientists to avoid provoking accusations of alarmism have led to an innate optimism bias. The official science reported by the IPCC may in some cases be a cautious underestimate. It’s likely worse – much worse – than we think.

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How does the IPCC approve reports?

IPCC reports are developed through multiple rounds of drafting and review. (See IPCC Factsheet – How does the IPCC review process work?) As the culmination of a report’s development, IPCC member governments endorse the report. The endorsement process is based on a dialogue between those who will use the report – the governments – and those who write it – the scientists. Endorsement by governments acknowledges that the report is a definitive assessment that has been developed following the IPCC’s defined procedures, underpinning the report’s authority. The IPCC has different levels of endorsement, including “approval”, “adoption” and “acceptance”1
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“Approval” is the process used for IPCC Summaries for Policymakers (SPMs). Approval signifies that the material has been subject to detailed, line-by-line discussion, leading to agreement among the participating IPCC member countries, in consultation with the scientists responsible for drafting the report. This process strengthens the SPM by ensuring that SPM statements are as direct, clear and unambiguous as possible in summarizing the material contained in the corresponding Working Group Assessment Report or Special Report. Participation of assessment authors ensures that any changes to the SPM are consistent with the underlying report and are scientifically robust.

“Adoption” is the process used for IPCC Synthesis Reports. Adoption is a section-by-section discussion leading to agreement among participating governments in consultation with the authors. This process ensures that the Synthesis Report effectively integrates material from the underlying Working Group Assessment Reports and Special Reports. The SPM of a Synthesis Report is approved line by line, as described above.

“Acceptance” is the process used for the full underlying report in a Working Group Assessment Report or a Special Report after its SPM has been approved. Acceptance by governments signifies that the Technical Summary and chapters of the underlying report present a comprehensive, objective and balanced view of the subject matter. Acceptance does not involve line-by-line discussion and consultation between the scientists and the governments. Changes (other than grammatical or minor editorial changes) after acceptance are limited to those necessary to ensure consistency with the Summary for Policymakers, and are identified in writing after SPM approval.

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