Several experts familiar with the IPCC government approval process for the 'Summary for Policymakers' (SPM) reports – documents summarising the thousands of pages of technical and scientific reports for government officials – have spoken out about their distortion due to political interests.
According to David Wasdell, who leads on feedback dynamics in coupled complex global systems for the European Commission's Global System Dynamics and Policy (GSDP) network, "Every word and line of the text previously submitted by the scientific community was examined and amended until it could be endorsed unanimously by the political representatives."
In a detailed paper critiquing the WG1 Summary for Policymakers, Wasdell revealed that: "Greatest pressure to establish grounds for the highest possible budget came from those countries whose national economy, political power and social stability depend on sustaining the asset value and production revenue derived from exploitation of their resources of fossil energy. Additional pressure was applied to the political agents by those vested interests whose sustained profitability was based on the extraction, refining, marketing and use of fossil energy as the ground of the global economy."
As an accredited reviewer for the IPCC's 2007 Fourth Assessment Report, Wasdell had previously criticised the political approval process for playing down amplifying feedbacks which could accelerate climate change. That charge was strongly denied by the IPCC's lead authors at the time, although political interference amounting to "scientific vandalism" was alleged by other sources….