I think you are right that you can't win a debate, not only about climate change, but about any reasonably complex scientific issue, with someone who knows what they're doing. I believe, for example, that it is unlikely life would be found on any planet orbiting a red dwarf star, because I have no reason to distrust the vast majority of astronomers. At the moment this particular scientific majority opinion is politically uncontroversial; but if some industry group were to find itself threatened by it and invested huge amounts of money in poking holes in tiny details of astronomy papers, accusing astronomers who talk about starspots of fearmongering and conspiracy, etc., I'd soon find myself out of my depth and unable to win the argument. So it's essentially a debate about trust in scientific authority, not about the science itself.Update: Here's a real world example for you to consider. Does exposure to the sun increase cancer risk? Of course there's no clear evidence of that, at least according to some people wearing white coats.
John McCarthy is right in identifying something he calls "lawyer's science", but he's wrong in identifying who most commonly uses it. Unlike those of us in the public sector, industry has a "bottom line".
This leaves them unconflicted about, well, if not actually lying, at least misrperesenting the balance of information within the limits of the law. You may imagine that a well ordered marketplace would impose consequences on this sort of behavior, but we are all too overwhelmed for that to happen effectively. I would imagine that they would at least be punished by sleep disorders, but apparently the population of sociopaths who sleep like angels is sufficient to overcome this.