How to Moderate a Discussion of Global Warming?

As noted in the previous post, I’m supposed to be moderating a panel at Boskone the weekend after next, with the title:

Global Warming: Facts and Myths, (and all that jazz)

This is not my usual line, but then, I don’t have to provide expert commentary, I just need to steer the discussion. Still, it would be good to have some idea where to steer it, so I will throw this out to the larger ScienceBlogs community:

What should I make sure to talk about in a panel on global warming facts and myths?

Of course, there are some additional constraints:

1) I’m looking for general discussion topics, not PowerPoint slides. I’m not talking about global warming, I’m moderating a discussion in which other people are going to talk about global warming.

2) I would like to avoid having the discussion cycle through the same things everybody has heard a billion times before. Something new and preferably interesting would be nice.

3) I would like this panel not to be soul-crushing. If I wanted fifty minutes about how we’re all gonna diiiieeeee, I would just go in and say to the panel “Tell us how we’re all going to die.” And then take a cyanide capsule, because it’s not only depressing to hear about our inevitable doom, it’s boring as hell, and see point 2.

4) Some connection to science fiction would be nice. It’s not strictly necessary, but it would be nice.

So, suggestions?