You originally said that to be consistent, if I shout down someone who says X is true, I should also shout down someone who says X is false. I didn't need to bring up "authority" at all to point out what a dumb statement that was.
OK, I should have written my comment from Nye's perspective not mine. If these "farmers" and "programmers" aren't qualified to speak then neither are democrat politicians nor green campaigners, regardless what opinion they hold. Only the high priests of science should be allowed to say anything. If Nye is going to apply appeal to authority then he should, at least, apply it consistently. You are making the mistake of assuming that a conclusion is all there is to an argument.
Consensus is part of the scientific method. You come up with a theory, test it with an experiment, publish your conclusion, and subject it to peer review where it may or may not gain consensus
No, consensus is part of the way science is done today (and not part of (formal) peer review, btw). The essential scientific method is observation > (falsifiable) hypothesis > experiment to test > review hypothesis > repeat. Now there is a LOT of research published today, no individual could ever review all the data and hypotheses and form their own conclusions on everything: that's where scientific consensus comes in - it's a shortcut made of pragmatic necessity.
As for the peer review process the reviewers are assessing your paper for scientific integrity, reasonableness and originality (and whether it meets the journals standards of "importance"), nothing more. Now, in utopia, there exists an informal review process where others try and repeat your experiments, add to your conclusions, test your reasoning and so on; ultimately your work will be discarded or accepted. The reality is that this never happens for most papers, but even when it does that process in itself does not lend validity to the conclusions, only the additional data and reasoning provided do so.