My neighbor who lurks here reports that her niece can't hear arguments against man-made climate catastrophe; she fends them all off with the assumption that they're funded by the Koch brothers. If she could listen, this would be a good place to start: a fair-minded fellow who tries to make basic, non-threatening points to a group of nice college kids. The Q-and-A session afterwards suggests that not much got through, but you never know. For every well-meaning question posed with a confused lack of rigor, there may have been several kids quietly wondering if the whole thing makes as much sense as everyone's been telling them it does all these years.
It's very discouraging to me that it's so difficult to concentrate anyone's attention on the failure of our climate models to make verifiable predictions, let alone on more difficult questions like "Even assuming you're correct about the probable severity of the problem, is the policy you're proposing to cure it actually likely to cure it?" and "If so, at what cost, and how does that cost compare to the benefit?"