"Just 12 years after the arrival of the 6 billionth individual on the planet in 1999, humanity will greet the 7 billionth arrival this month. The world population continues its rapid ascent, with roughly 75 million more births than deaths each year. The consequences of a world crowded with 7 billion people are enormous. And unless the world population stabilizes during the 21st century, the consequences for humanity could be grim," warns Jeffrey Sachs of Columbia University in a CNN story.

"So the arrival of the 7 billionth person is cause for profound global concern. It carries a challenge: What will it take to maintain a planet in which each person has a chance for a full, productive and prosperous life, and in which the planet's resources are sustained for future generations? How, in short, can we enjoy "sustainable development" on a very crowded planet?"