Population Factsheets - Global Population and Environment

Land and the natural environment are limited resources that a growing population and poor land-use planning often strain. As we seek to rein in sprawl, we must work to address all its causes. Many strategies have been proposed to help stem unchecked development, and as we seek solutions, it is appropriate to address the complex relationship between sprawl and population growth.

A recent survey by the Pew Center for Civic Journalism found that suburban sprawl ties with crime as a top local concern for most Americans. It's not hard to figure out why: Americans are fed up with losing parks to pavement, breathing polluted air and spending an average of 55 workdays in traffic every year. We can do better to rein in out-of-control sprawl and slow population growth with simple solutions such as good land use planning, greater transportation choices, and increased support for family planning.

Population-Sprawl Overview in U.S. Cities. According to a recent study of 277 metropolitan areas, from 1960-1990 our western cities nearly doubled in population, southern cities increased 70 percent, and population in cities in the Midwest and the Northeast grew by a more modest 25 percent and 12.5 percent respectively.
Data from Leon Kolankiewicz and Roy Beck,"Weighing Sprawl Factors in Large U.S. Cities," 2001.

So why do we keep sprawling and overdeveloping? Sprawl has more than one source. As Sierra Club's two most recent national sprawl reports have shown, a complex mix of billions of dollars in government subsidies and poor federal, state and local planning policies fuels haphazard growth. Beyond that, in many but not all regions, rapid population growth further fuels sprawl.

Nationwide, land consumed for building far outpaces population growth. Urban areas expand at about twice the rate the population is growing.¹ A regional breakdown of the data shows some significant variations. In some regions of the United States, sprawl is largely a consequence of residents moving from urban centers to suburbs, but in others, population growth plays a larger role.

Population growth is clearly a bigger sprawl factor in the South and the West than the Midwest and Northeast, particularly along the Atlantic coast.²

In fact, according to a recent study of 277 metropolitan areas, from 1960 to 1990 our western cities nearly doubled in population, southern cities increased 70 percent, and population in cities in the Midwest and the Northeast grew by a more modest 25 percent and 12.5 percent respectively.³

Sprawl in many parts of the Midwest and Northeast is largely a product of poor land-use planning, irresponsible development and the migration of people to sprawl areas. In these communities, poor planning and lack of regional cooperation play larger roles than population growth.

Some notable examples of this phenomenon include Detroit, Pittsburgh and Chicago. From 1970 to 1990, Detroit's population shrank by 7 percent but its urbanized area increased by 28 percent. Pittsburgh's population shrank 9 percent in the same period and its area increased by 30 percent. Chicago's population did increase between 1970 and 1990 by one percent. Meanwhile, its urbanized area grew by 24 percent.⁴

As affluent residents flee, the tax base and quality of city schools declines, crime increases, green spaces shrink, and infrastructure is neglected�ultimately leading to more flight.

In the southern and western regions, these same factors combine with population growth to drive sprawl.5 Nashville, Charlotte, and Phoenix depict how rapidly expanding population contributes to sprawl. Between 1970 and 1990, Nashville's population grew by 28 percent while its urbanized area grew by 41 percent. Charlotte's population grew by a significant 63 percent during this period while its urbanized area grew by a staggering 129 percent.

Sprawl and concurrent population growth in Phoenix provide a frightening glimpse of the repercussions of unchecked growth combined with poor planning: From 1950 to 1970, while its pop- ulation grew 300 percent, its urbanized area grew by an incredible 630 percent.6 More recently, its population grew 132 percent from 1970 to 1990; its urbanized area grew by a similarly significant 91 percent.

Solutions
There are effective ways to curb both sprawl and slow population growth. While slowing population growth is one critical step, it alone isn't the only answer. We also need to invest more in cleaner public transportation alternatives like trains, invest more in our existing communities rather than subsidizing fringe sprawl to help us rein in suburban sprawl. Cutting subsidies that feed sprawl, reinvesting in existing communities and Smart-growth techniques, such as mixed-use, infill, and transit-oriented development, can channel growth away from open space and sensitive habitat into areas with established infrastructure and existing resources.

But no matter how smart the growth or how good the planning, a rapidly growing population can overwhelm a community's best efforts. Access to affordable family planning offers families a proven way to slow population growth. When families have the freedom to choose how many children to have and when to have them, families tend to be smaller and healthier. Women who have access to reproductive health care and family planning are better equipped to protect their health and the health of their families. Access to quality family planning programs truly is a win-win situation for the environment.

Notes
1 "The State of the Cities 2000," U.S. Department of Housing and Urban Development.
2 Diamon and Noonan, Land Use in America, Island Press 1996, p. 87; Benfield Raimi, and Chen, Once There Were Greenfields, Natural Resources Defense Fund, p. 5; Porter, Managing Growth in America's Communities, Island Press 1997, p. 4; See also Bartlett, Mageean, O'Connor, "Residential Expansion as a Continental Threat to U.S. Coastal Ecosystems," Population and Environment, Volume 21, Number 5, May 2000.
3 Janet Rothenberg Pack, "Metropolitan Areas: Regional Differences," Brookings Review, Fall 1998, p. 27.
4 U.S. Census Bureau.
5 Bartlett, Mageean, O'Connor, "Residential Expansion as a Continental Threat to U.S. Coastal Ecosystems," Population and Environment, Volume 21, Number 5, May 2000.
6 U.S. Census Bureau.