Maybe not slow learners but perhaps need a little more evidence & rigour before changing the economic dynamics of the World. Don't think for one moment that computer simulations programmed by people who think there may be climate change pass for rigour.
The fact that you state the debate is "no longer about whether we are contributing to climate change..." is typical of an approach that eschews intelligent discussion and just accepts a prima facie case. The whole debate has now been hijacked by so many self-serving interests I'm not sure we will ever get the bottom of it. Maybe when someone notices that the World has started to cool again then they'll all bugger off on another "vital" topic!
You make it sound as if the climate change debate just popped up in the last couple of years. It has been going on for such a long time that the overwhelming majority of scientists have accepted the reality of the situation. Opinions differ as to the likely effects, but the notion that human activity does not play a role is no longer taken seriously. Most would agree that the "world is round" discussion doesn't really need a little more discussion, although I'm sure there if you looked hard enough you'd find a differing opinion.