The IPCC is not a self-selected group of scientists with a political agenda. [...]
The IPCC is too big an organisation to be captured by an ideological cabal or fall foul of group-think. It draws in scientists from every discipline from many different nations. Climatologists from Benin rub shoulders with scientists from the West, and from Saudi Arabia and other petrol-states for whom belief in global warming is against their immediate interests.Firstly Prof H fails to point out that the IPCC's scientists are all nominated by governments and that governments are not always the neutral bodies some would like to think they are. More seriously he ignores the evidence that certain IPCC lead authors and section editors certainly did attempt to force through one particular viewpoint despite complaints from those who disagreed. See comments by Pielke Sr, Pielke Jr and McKitterick to name just three off the top of my head.
The IPCC process also makes it impossible for green propaganda to be slipped in. The IPCC has published four reports — in 1990, 1995, 2001 and 2007. Each contains three volumes covering science, impacts and mitigation; in 2007 each volume was about 1,000 pages long. Their main content is a detailed review of thousands of peer-reviewed scientific papers. But a report from Greenpeace or any other campaigning body would not be included because the science would not be considered robust enough.This is in fact a bare faced lie. Some of the more alarmist chunks of sections 2 and 3 appear to have been sourced from the WWF, Greenpeace and so on. It is true that the main contesnt is a review of thousands of scientific papers but the bits that get the coverage - the reported imminent melting of glaciers, starvation in Africa, desertification of the Amazon rain forest etc. seem to have not come from such a rigorous process but to have come from "Greenpeace or [...] other campaigning bod[ies]"
A further myth is that the IPCC is alarmist. In truth, it’s far easier to find what now looks like excessive caution in IPCC reports. For instance, the 1990 report stated that increases in greenhouse gases were causing global warming but added that, because of natural climate variability, this warming could not be clearly detected in the observed record. As warming has continued at about the rate projected by the reports, each subsequent report has in general shown increasing confidence in its conclusions.[...]
A third myth is that the IPCC has refused to recognise that there has been no significant increase in global average temperature in the past decade or so. Sceptics cite this as evidence against human-induced global warming. But the level of natural year-to-year variability in the temperature record shows that a decade is too short a time to establish a change in the long-term trend.This section seems a tad over optimistic. I'm not sure what warming rates the IPCC itself put down but from the work by Lucia it is clear that the models used by the IPCC and others have, since around 2000, significantly overestimated heating. Indeed Prof Phil Jones himself said temps since 1995 had increased only at 0.12C/decade which is just 60% of the 2C/century that I've seen quoted in many places as the IPCC projected increase.
Perhaps there is a criticism that can be made of IPCC scientists: they have been too slow publicly to defend their integrity. They have not been willing or able to hit the airwaves or make their case in newspapers. But scientists are now faced by powerful lobbies who are working to distort and discredit the science behind climate change. We scientists have facts on our sides — we must not be afraid to deploy them.I would say that if the IPCC scientists have failed to defend their integrity then that is perhaps because every time they seem to have tried they have been shown to have been somewhat economical with the actualité. Furthermore it is worth pointing out that the really powerful lobbies have, until recently at least, been solidly on the side of the IPCC and its band of alarmists. Politicians and government funding have all leant heavily towards the AGW is a danger side of the equation and funding of the skeptics has been minimal. Despite such minimal funding skeptics have demonstrated significant weaknesses in a number of IPCC sponsored claims regarding global warming. If anyone has been distorting the science it is the environmental lobbyists.