Despite acknowledged selectivity of data, the role asked of IPCC nations expands with every meeting. Such a role goes far beyond assessment, but is perhaps unavoidable, given the necessity to think that we know what might scientifically be happening as a result of human activity. Participants at COP6 are depending on IPCC work. The process appears to divide IPCC scientists and not seek their collaboration in the end result. Politicians write the policy summaries, not the scientists.
Politicians leave much out of the final reports.
Rarely is underlying work in total agreement. IPCC chapters may actually disagree with each other and may have reached different conclusions, but final reports are cleansed to present one supportive position. All data agree that the climate warmed up until about 1940, but not between 1940 and 1980. Its column of Nov 27 reports the work of an obscure German biogeochemist on CO2 storage in forests and soils. Significantly, the story is under the rubric of Politics rather than Science.