The environmental movement has developed many tools to communicate within and without their own systems and societies. Or probably is better to say that as many other groups environmentalist have been using the tools developed by the general society at large for communication. Such is the case for the internet.
One important avenue has been "Youtube"! And here you will find a link to one of those "activists" that has done a lot to promote a discussion related to global warming. One of those links is to an Oregon science teacher that has been using youtube to enhance the discussion. This is one of those links: http://www.youtube.com/watch?v=kOjCcL1PN_Y