It’s reasonable, and even expected, for educated people to disagree with one another on this issue in the way described above. I think this back-and-forth exchange is common historically, and often occurs when science is operating as it should.
Where many AGW believers abandon the scientific method is when they revert to various logical fallacies to manipulate the average person’s emotions in order to gain support for AGW and its associated anti-fossil-fuel political program. AGW advocates commit the fallacy of ad hominem when they call researchers who disagree with their assessment of the strength of the case for AGW “deniers” — an obvious attempt to link them in the public’s mind with despicable Holocaust deniers. That is not science, it’s rhetoric. I know of no one who denies the fact that climate changes, but there are legitimate disagreements concerning the extent of humanity’s role in present climate change and whether it will be disastrous. Scientists who refuse to admit that highly regarded scientists disagree with AGW are the ones who should be labeled “deniers,” and thus suffer the opprobrium rightfully attached to that label.
AGW proponents also commit the fallacy of appeal to numbers, when they say the case for dangerous human-caused climate change is settled because some high percentage of a subset of scholars agrees humans are causing dangerous climate change. Consensus is a political, not a scientific, term. The world once thought Earth was flat. Galileo said he disagreed and that he believed it was round (and he suffered for saying so). And you know what? He was right and the consensus of the time was wrong. At one time, the people, including the intellectual elite, believed Earth was the center of the universe and the Sun revolved around it. Copernicus said just the opposite. He was right, and everyone else was wrong.