Are polar bear populations shrinking or not is the question at hand. A scientist checks to see if that's happening. A true believer asks what the priests say. At one point it was settled science by consensus that the earth was flat.
Actually, no.
All the way back to the Ancient Greeks, scientists knew the world was round. So did most sailors. Your piss-ignorant peasant who never traveled more than 50 miles from where he was born thought it was flat..
We have a lot of evidence that the globe is getting warmer... dying coral reefs, melting permafrost, shrinking glaciers, and so on.
What we have is what credible scientists - 97% of them- realize, and what the Koch Brothers pay for to confuse the issue to prevent serious action from being taken.
Okay, if you don't like the flat Earth idea, there are plenty more. It was settled science by consensus that the Earth was the center of the solar system, that flies sprang spontaneously from rotting meat, and mice from straw. The point is, using "the science is settled by consensus" to silence dissenting voices is not science, it's politics and cult belief.
Again the question is whether polar bear populations are shrinking, growing, or remaining constant. It's not a political issue, it's a measurable one. If the professor is correct that populations are increasing, he not only doesn't suck at his job, he deserves a big payout from a wrongful termination lawsuit.
A professor's job is to pursue truth, not regurgitate orthodoxy.