Feeling a little crowded, are we?
The United States population is growing at record-breaking rates - 58,000 per week or 3 million a year. At this rate, calculates the Census Bureau, the US will swell by another 125 million people by the time today's toddlers have become grandparents.
It's not that more Americans are suddenly discovering the joys of parenthood. Rather, nearly two-thirds of the US growth rate is due to immigration. And that is where demographics and environment are colliding over the future of US population policy.
Over the weekend, the 550,000-member Sierra Club announced the results of its controversial mail-in vote on whether one of the largest and most politically active groups in the country should change its stand on immigration.
To the relief of club leaders, most members rejected a measure advocating a lower limit on the number of immigrants allowed into the country every year. Instead, the group will stick with its "neutral" stand on immigration. "Birth control, not border patrol, is the common-sense solution," said Carl Pope, executive director of the Sierra Club.
The referendum highlights a split in the environmental and population control communities. Some say US immigration policy, which is far more liberal than any other nation (not counting the 200,000-plus people entering the country illegally each year), cannot be ignored in reckoning the environmental impact of a soaring population growth rate.
While the past several decades have seen marked improvements in some areas - air and water quality, for example - some observers worry that the cumulative effect of more people and a more affluent economy undermine these improvements. "If the population increases ... to 393 million by 2050, will our current environmental victories survive?" asks Mark Nowak of the advocacy group Negative Population Growth.
OTHERS argue that turning newcomers into scapegoats appears racist and elitist, and it makes it easier to ignore the fact that most of the consuming and polluting is done by longtime, better-off Americans.
"The most effective strategy for dealing with [US] immigration ... is to relieve the conditions that compel people to leave their homes, which range from population growth and poverty to political repression," says Judith Jacobsen of Zero Population Growth.
Others assert that consumption - not population - is the more important issue. "If you make self-indulgence the basis of human life, then you shouldn't be surprised if people don't treat each other well and don't act responsibly," says Richard Anderson at the University of California at Santa Barbara.
It is a minority view, but some experts say a rising US population is not necessarily bad for the environment.
"There is no population bomb that free markets cannot defuse," says Thomas Lambert at Washington University in St. Louis. "Human innovation - a limitless commodity - continuously creates new resources and extracts increasing amounts of services from currently used resources."