In the January/February edition of Foreign Affairs, Jack Goldstone has a cover story [The New Population Bomb], which warns that population growth and other population trends pose a significant challenge to efforts to end global hunger and eliminate severe poverty. He suggests, among other things, that high food prices will pose a special challenge to the world's urban and the international relief agencies working to end global hunger. Goldstone also warns that countries "with younger populations are especially prone to civil unrest and are less able to create or sustain democratic institutions."
http://www.foreignaffairs.com/articles/65735/jack-a-goldstone/the-new-population-bomb