Here is an enlightening article that explains how "consensus" is gained by the UN's Inter-Governmental Panel on Climate Change (IPCC). It's well worth reading in total, but here are some eye-raising snippets:
To better understand the “consensus” presented in the policymakers’ summaries, it is helpful to be aware of the structure of the IPCC. Those who compose the summaries are given considerable latitude to modify the scientific reports.... Here is a specific example: One policymakers’ summary omitted several important unequivocal conclusions contained in the scientists’ report, including, “No study to date has positively attributed all or part [of observed climate change] to anthropogenic [i.e., man-made] causes,” and “None of the studies cited above has shown clear evidence that we can attribute the observed changes to the specific cause of increases in greenhouse gases.” These significant revisions were made, according to IPCC officials quoted in Nature magazine, “to ensure that it [the report] conformed to a policymakers’ summary.”
The sponsors of the IPCC, the United Nations, and liberal American politicians all share the goal of reducing Americans’ wealth by capping our consumption of energy with a binding international climate change treaty. They are willing to resort to scientific fraud to further their goal. In the words of Al Gore’s ally, former Under-Secretary of State Tim Wirth, “Even if the theory of global warming is wrong, we will be doing the right thing” by reducing Americans’ consumption of fossil fuels. Keep that in mind whenever the IPCC is cited in support of a climate treaty.