On October 31, 2011, a particularly special person will be born—the seven billionth human alive, according to United Nations demographers. He or she could be delivered by a starving mother in the growing wastelands of Somalia, a failed-state gripped by famine and war. The best odds are that the child will be born in India, which has the highest rate of births per minute in the world. She may even be an American girl, heiress to a complex legacy that is in no small part responsible for the fact that, for better or worse, people are shaping the destiny of the planet that engendered humanity.
Regardless, the seven billionth person raises the question: How much is too much? "Can Earth support seven billion or nine billion or 10 billion people in a good life for a long time?" asked demographer Joel Cohen of Columbia University's Earth Institute at itshuman population event on October 17. "The addition of four billion people in five decades has no precedent. That is an exceptional event and will probably never be repeated within human history."