The human population will reach 7 billion by the end of the month, according to United Nations, and that's no milestone to celebrate, says Jeffrey D. Sachs, director of The Earth Institute.
Instead, we need to be concerned, he says. It's been only 12 years since we welcomed the 6 billionth human, and Sachs predicts it's likely only another 13 or 14 years before the population adds another billion people.
"This is a crowded planet," says Sachs. "This is trouble, frankly, for the planet." With this many people and counting, feeding, sheltering and protecting ourselves creates enormous environmental and economic challenges.
Can we prosper with this many people?
The key to managing it, Sachs says in the accompanying interview, is to begin to stabilize the population. One important way to do that is to lower fertility rates. And, the best way to do this is to reduce infant mortality rates, which on the surface may seem contradictory, but not as Sachs explains.
"When children survive predictably then parents choose to have fewer children," he claims. That is why parents in the developed world tend to have less children than those in poor nations. "In the high-income and most of the middle-income countries, population is stabilized. It's in the poorest countries -- where you don't have access to health care, family planning, where the children die in large numbers, where the girls aren't able to stay in school -- that the population is soaring."
Still, the developed world causes its own stresses on the planet. In a way, we're victims of our own success. The rising price of commodities around the globe isn't simply about supply and demand caused by a growing population, it's also the result of rising income per person. With a growing global middle class, there's a larger population able to buy meat, heat their homes and drive cars.
"That is shaking the world economy, no doubt about it," Sachs says. It's also an environmental concern that calls for newer and more sustainable technologies, he says.
Sachs believes it's possible to make these changes, but it will take enormous cooperation -- which isn't always easy for a small group to do, forgot about the entire civilization.