Overpopulation is bound to happen at some point. Many say it already is at that point. The Chinese even institute a one child policy (ironically leading to there being too few girls in China because people start messing with Gaussian distribution to continue their family lineage).
Land and resources are limited. What will be the consequences for economy, land, etc? Who will suffer first, how and why? What's next? How can you prevent it? How can you prolong the inevitable? Is there any point in food-aid if the next food shortage is only going to be worse?
Some questions to get you started.
