WASHINGTON (AP) -- As the U.S. population speeds toward 300 million, the growth is producing headaches for Americans fed up with traffic congestion, sprawl and dwindling natural resources.
But the alternatives are pretty scary, too. Just look at Europe and Japan, which are on the verge of such big population losses that several countries are practically begging women to have babies.
"Europe and Japan are now facing a population problem that is unprecedented in human history -- declining population over time with an increase in the percentage of old people," said Bill Butz, president of the Population Reference Bureau, a Washington think tank.
Countries have lost people because of wars, disease and natural disasters but never -- at least in modern history -- because women stopped having enough children, Butz said.
The U.S. is the fastest growing industrialized nation in the world, adding about 2.8 million people a year. That's a little less than 1 percent, but enough to mitigate the kinds of problems facing Japan and many European countries.
Europe, with 728 million people, saw its population shrink by 74,000 since the beginning of the decade, according to the United Nations. By 2050, it is projected to lose a total of 75 million people.
That ought to give motorists on Germany's Autobahn some extra room to change lanes. But experts warn it could cause labor shortages while straining retirement and health programs, ultimately threatening economic competitiveness.
The problem is that birth rates are so low there aren't enough young people entering the work force to support an aging population, said Hans-Peter Kohler, an associate professor of sociology at the University of Pennsylvania.
"Presumably, many people would not be so concerned about the numbers declining if it wasn't combined with an aging population," Kohler said. "I think it's more the age structure that gives rise to these concerns, and these concerns are well justified."
Russian President Vladimir Putin is so concerned he recently proposed paying women to have children. Last year, France increased monthly stipends to parents who take time off work to care for a third child.
When Japan announced in June that its population had shrunk in 2005 for the first time, Prime Minister Junichiro Koizumi said, "The data must be accepted gravely."
On Friday, Japan announced that it is now the world's most elderly nation, with more than a fifth of its people 65 or older. Italy is second.
On average, women must have 2.1 children in their lifetimes for a society to replenish itself, accounting for infant mortality and other factors. Only one country in Europe -- Albania -- has a fertility rate above 2, according to statistics gathered by the Central Intelligence Agency. Russia's fertility rate is 1.28. In Japan, it's 1.25.
"We're going to have the chance to learn from Europe," Butz said. "For better or worse, they are leading the world into something that has never happened before."
John Seager, president of Population Connection, predicted that any adverse affects of shrinking populations will be temporary.
"It may be the only good crisis we ever had," said Seager, whose group, formerly known as Zero Population Growth, advocates lower birth rates.
Personally, I just enjoy the idea of a "Start Humping For The Love Of God" campaign going on in Europe and Japan.