Der Spiegel has done a nice job assembling the history of the politicization of climate science. The article concludes:
(…) However, it seems all but impossible to provide conclusive proof in climate research. Scientific philosopher Silvio Funtovicz foresaw this dilemma as early as 1990. He described climate research as a “postnormal science.” On account of its high complexity, he said it was subject to great uncertainty while, at the same time, harboring huge risks.
The experts therefore face a dilemma: They have little chance of giving the right advice. If they don’t sound the alarm, they are accused of not fulfilling their moral obligations. However, alarmist predictions are criticized if the predicted changes fail to materialize quickly.
Climatological findings will probably remain ambiguous even if further progress is made. Weingart says it’s now up to scientists and society to learn to come to terms with this. In particular, he warns, politicians must understand that there is no such thing as clear results. “Politicians should stop listening to scientists who promise simple answers,” Weingart says.
Roger Pielke Jr. is engaging readers on some of the contentious points, such as “hide the decline”. There is more detail and background in Climategate: Steve McIntyre examines The “Trick” in Context:
Roger looks at Steve McIntyre’s examination of the “trick”. It does not tell us that the warming trend is false. But it does reveal that the IPCC inner circle put a lot of energy into spin.