I think the most fascinating part of the future of our planet to speculate on is the carrying capacity. At what point will our planet experience a catastrophe due to sheer populations numbers? Or more likely, when will a catastrophe be made much worse because of overpopulation? I'm pulling this figure off the back of my brain, but I want to say the predicted max world population in 2050 is 12 billion. How the hell are we going to support all these people? Existing programs in developed countries are already under stress, and developed countries are experiencing civil unrest due to large unemployed youth cohorts. I personally think a strict population control program along the lines of China is required to mitigate these problems, but they will never be enacted. Instead, the world will just be bogged down by an excess number of people and will settle around a miserable number of people. perhaps 9 or 10 billion.