World population hits 7 billion

Today will go down in history as the day the world's seven billionth human was born, at least symbolically, because it's impossible to accurately identify the truly seven billionth baby, and whether indeed today was the day. What's worrying is the speed with which the population is growing - we crossed from six to seven billion in less than 13 years and most of this growth is in the developing world, where there is already a struggle for scarce resources.