As more and more people are squeezed economically, all existing tensions will be exacerbated. The biggy is when enough people start to struggle to consume enough calories that s** really starts to hit the fan. I would expect every geo-political problem, every cultural problem, every domestic problem to get worse.

Whatever is going to happen is going to happen soon. Such is the nature of exponential growth. Everything seems to happen all of a sudden at the end, despite the rate of growth potentially remaining constant. Then some period of radical adjustment, as all exponential growth of any system in the real world is unsustainable and must end.