Just to throw my input into here, I would like to say to Pamela and Fraser that it is a great idea to throw a good half-hour to the global warming issue for its effects on the biosphere and composition of the atmosphere in era's to come. It would be extremely interesting to have an astronomical viewpoint on the matter which i have not had the pleasure of experiencing yet. I like the Idea, and I can't wait to see if anything comes out of this!