join me next time for conversation with demian bichir and jonathan butler. that's next time.ee you then. >> announcer: tonight on quest, the climate is changing. it's not a question of if or when, it's happening now. scientists already have clear evidence that california is warming, affecting everything from water supplies to wildlife. and looking into the future, what kind of state will our children inherit? most experts agree that the decades ahead will be very different from the california we've all been used to. >> we've dubbed the phenomena that we're looking at the "four horsemen of the apocalypse." >> the world of 2050 is already in the pipeline. and the question is, if we're going to be smart enough to avoid the worst of it. >> those people that are still skeptics that don't believe, that think that we ought to just wait, let nature take its cose