Gavin Schmidt and some other climate scientists debated some Denialists (Lindzen, Chrichton,...) the other day and apparently got their asses kicked. This is not a surprising result to anyone who has ever observed a scientist debate a creationist. Most scientists are lousy debaters, because they think it's all about the evidence, and want to be careful to frame their arguments clearly and precisely. Lawyers, politicians, and preachers realize that public debate is about rhetorical skill, demonstrating weakness in the enemy, and sowing confusion. For people like that, debating a scientist is a bit like shooting fish in a barrel.
Complex issues, like evolution or climate change are perfect for the merchant of doubt. An analogous situation is often seen when somebody confronts a TV pundit in debate. The victim shows up with an argument they want to talk about, but the host has an agenda. Moreover, he has a domineering personality, the crew, plenty of primetime experience, and three makeup girls.
The erstwhile debater's position isn't helped by people going around predicting that anthropogenic climate change will make world war "look like a picnic." That kind of scare mongering just discredits more thoughtful analyses.
My guess is that the doubters will manage to obstruct meaningful action until the evidence becomes obvious - until the effects start hurting people directly. That is already occurring for a small number of people, but many more will need to affected first.
Thus, it might not be too soon to start building your virtual ark. Find someplace predicted to remain habitable and stock up on gold and ammunition.
If you really do want to have a debate, pick a spokesperson (probably got to be a spokesman) who is pretty, well-groomed, and rhetorically skilled. And have him practice for weeks against some skilled litigators. Or just let the litigators do the talking.