The public tends to think that scientists, particularly Nobel Laureates, are knowledgeable about all facets of science. The truth is that, while they tend to be highly intelligent, they are truly expert in only one or two rather narrow fields. The whole business of global warming (or climate change) involves a multitude of scientific disciplines all of which it is impossible for one person to have mastered. The result is a collaboration of a great many people, all of whom are trusting that the others are correct in their assessments which are necessarily deficient because of the authors incomplete knowledge of the entire system. Here is an article that discusses this issue that the UN IPCC has not addressed.