A flotilla of 100 fishing boats, rafts, and kayaks crossed the
Willamette River to a downtown park in Portland, Ore., the other
evening to rally for the Pacific Northwest's reigning icon: wild
salmon, now plummeting toward extinction due to development across
much of the Columbia River basin.
It was a typical event for a "green" city that has one of the
best records in the United States for recycling, reducing greenhouse-
gas emissions, using alternative energy, and providing public
transportation and bike paths.
But Portland's amenities - its natural setting along the
Willamette River and its youthful techie vibe - are drawing a surge
of new people, threatening to erode the very qualities that drew
people here in the first place. As the US approaches 300 million
people, that's the story of the nation as well.
In many ways, Americans have mitigated the impact of their
increasing presence on the land. Since reaching the 200 million mark
back in 1967, they have cut emissions of major air pollutants,
banned certain harmful pesticides, and overseen the rebound of
several endangered species. Despite using more resources and
creating more waste, they've become more energy efficient.
The danger, experts say, is that the US may simply have postponed
the day of reckoning. Major environmental problems remain, and some
are getting worse - all of them in one way or another connected to
US population growth, which is expected to hit 400 million around
midcentury. Some experts put the average American's "ecological
footprint" - the amount of land and water needed to support an
individual and absorb his or her waste - at 24 acres. By that
calculation, the long-term "carrying capacity" of the US would
sustain less than half of the nation's current population.
"The US is the only industrialized nation in the world
experiencing significant population growth," says Vicky Markham, of
the Center for Environment and Population, a nonprofit research and
advocacy organization in New Canaan, Conn. "That, combined with
America's high rates of resource consumption, results in the largest
... environmental impact [of any nation] in the world."
The boomer challenge
The changing nature of the population also has environmental
"Today's baby boomers - 26 percent of the population - are the
largest, wealthiest, highest resource-consuming of that age group
ever in the nation's history, and they have unprecedented
environmental impact," says Ms. Markham.
The generation's preference for bigger houses and bigger cars -
and the proliferation of them - are gobbling up more resources and
creating more pollution, according to a recent study by the Center
for Environment and Population. For example:
* Land is being converted for development at about twice the rate
of population growth. When housing, shopping, schools, roads, and
other uses are added up, each American effectively occupies 20
percent more developed land than he or she did 20 years ago.
* Nearly 3,000 acres of farmland are converted to nonagricultural
* Each American produces about five pounds of trash daily, up
from less than three pounds in 1960.
* While the US is noted for its wide open spaces, more than half
of all Americans live within 50 miles of the coasts where population
density and its environmental impact are increasing.
That concentration poses special challenges for areas near the
coast, like Portland, where land is rapidly being gobbled up. The
city's population, which is now a bit over half a million, is fairly
stable. But surrounding population pressures are great. The
metropolitan area grew about 30 percent during the 1990s to just
over 2 million. It's projected to grow to 2.6 million by 2010 and to
3.1 million by 2025.
Some groups worry that Portland's growth will undermine its
environmental sustainability. …