Honestly I think the world will end in war, or nuclear weapons. America will soon run out of fresh water along with most of the world. Canada has most of the worlds fresh water, so America will at one point take it by force or another place will. After that we may run out of oil causing the world to go into the amish. Global war will soon break out for need of water, and oil not to mention most of the population dieing from lack of water. Then when you think it's all over we have to worry about gobal warmming. Will polution ice will melt causing floods all over the world. So the world will end because of humanity's mistakes, and miscares about finding better resources. (Fresh water we can't really fix).
The whole Mayan calender thing has already been denied by those who believed in it, cause another calender found went past 2012. LOL