From an interview by David Roberts with Al Gore on his forthecoming film "An Inconvenient Truth":
There's a lot of debate right now over the best way to communicate about global warming and get people motivated. Do you scare people or give them hope? What's the right mix?
I think the answer to that depends on where your audience's head is. In the United States of America, unfortunately we still live in a bubble of unreality. And the Category 5 denial is an enormous obstacle to any discussion of solutions. Nobody is interested in solutions if they don't think there's a problem. Given that starting point, I believe it is appropriate to have an over-representation of factual presentations on how dangerous it is, as a predicate for opening up the audience to listen to what the solutions are, and how hopeful it is that we are going to solve this crisis.
Over time that mix will change. As the country comes to more accept the reality of the crisis, there's going to be much more receptivity to a full-blown discussion of the solutions.