I have truthfully never thought about how the world would end, I mean, it is such a gruesome topic don't you think? But if the world really was going to end, I think it would have something to do with electricity, oil, or natural gas running out and the society we know today collapsing. I think the world will end eventually, but not any time soon. The scientists know we will eventually run out of these energy sources, so they are searching for an alternative source/sources. Of course, I have heard of the 2012 theory, but, um, hello? It IS 2012! And just so you know, they found the end of that Mayan calendar, so that theory is out of the question. I dont consider global warming to be a big threat either, because the climate of the planet changes a lot. Why do you think giant reptiles (dinosaurs) roamed the earth in prehistoric times? And they just suddenly went extinct? Because of the earth changing! That is what the earth does, it changes constantly. Ever heard of Pangea anyone? Like I said, I never really thought about the end of the world. For most people, I think, It never really occurs to think that everything we know is going to end in catastrophe someday! It is the very pessimistic approach to life, but I guess someone has to do it otherwise the world would crumble under the first problem that is faced! So thank you all those pessimists out there! What would the world do without you?