Demographics and resource preservation

"The world's most important arithmetic is

the arithmetic of the exponential function."

- Albert A. Bartlett, Carrying Capacity Network

he paradox is disturbing. Although ecologistsrecognize population dynamics as a core process of ecosystems, land managersand policy makers often fail to associate increases in human numbers withthe health of parks. This thinking persists because the consequences of compound growth are so subtle, accumulating day by unnoticeable day. Moreover, many view America's population as unchanging. But America's population will continue to grow during the 21st century, and bring unprecedented pressures to U.S. parks and other public lands.

America's population is growing 0.8% per year. Thanks to compound growth, this seemingly innocuous growth rate will do what larger growth rates do; it will simply take a little longer. The U.S. Bureau of the Census (1996) projects that America's population will rise from today's population of 268 million to 335 million by 2025. Compound growth at this same rate will double America's population in 75 years to more than half a billion people.

Moreover, the population of the United States is not expected to stop growing, because, as the Bureau of the Census reports, the global human population is growing at 1.56% per year-equal to about 90 million people. Immigration to America will inexorably increase as people across the world respond to the laws of economics and seek better lives. In 1996, immigrants accounted for 46% of the annual increase of 2.3 million in U.S. population. During the next century, according to the United Nations Population Fund, 94% of the world's population increase will occur in developing countries. In addition, the Population Fund estimates about 23% of the world's people, almost all in the developing world, live in absolute poverty, a condition described by former World Bank President Robert McNamara, as "so limited by malnutrition, illiteracy, disease, squalid surroundings, high infant mortality, and low life expectancy as to be beneath any reasonable definition of human decency." For these people, migration will often be the only way to find a better life.

The pressure of population increases will be felt in every state, but most of all in the U.S. counties contiguous with coastlines, the Great Lakes, and the U.S.-Mexico border. For example, the population of U.S. counties and Mexican municípios along their international border increased by 830% between 1930 and 1990. According to demographers John R. Weeks and Roberto Ham-Chande, this population of 9.34 million will double again in 22 years. The effects of people seeking to meet their basic needs in the arid Southwest are already conspicuous. The Río Grande below El Paso, Texas, is dry for most of each year. Due to continuing diversion from the Río Conchos watershed in Mexico, the Río Grande downstream in Big Bend National Park will likely become dry for part of each year.

Nearly half the U.S. population now lives within the 426 coastal counties, including the Great Lakes. Most of the population increase will come in these areas, where an estimated 1,000 acres of wetlands, the nurseries of the seas, are already being lost each day to development. Here and elsewhere, increased demand for minerals, water, fuel, fiber, and food will place unparalleled pressure on ecosystem functions.

Non-point sources of pollution also continue to increase. The nearly parallel relationship between population increases and atmospheric carbon dioxide and methane levels will continue. In addition, direct exploitation of parks will increase as both immigrants and long-established citizens seek ways to make a living from park resources. Anything salable and easily harvested, plants, animals, fossils, or minerals, will suffer exploitation.

In a sustainable society, parks provide many things, including ecosystem maintenance, healthy recreational opportunities for people, laboratories where the fundamental workings of ecosystems are revealed, and places where our natural and cultural heritage is preserved and discovered. But the welfare of parks is ultimately linked to the basic needs of the people of the world. If national parks and monuments are to survive with any semblance of environmental quality and integrity, the National Park Service must nourish public understanding that a sustainable society is possible only if its population is stable. The concepts of population dynamics and consequences of population growth must be fundamental parts of our educational programs. But this effort must also articulate the need to create sustainable societies around the world. Without global sustainability, national sustainability or the sustainability of parks is impossible.

Other articles in the "Threats" chapter:

Threats and information

Lake trout threaten native Yellowstone cutthroat

The perennial push of exotic plants

Communication breakdown over drilling near Lechuguilla Cave

Historic water rights settlement averts threats at Zion

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E-mail jeff_selleck@nps.gov

United States Department of the Interior
National Park Service
Natural Resource Information Division
Academy Place, Room 450
P.O. Box 25287
Denver, CO 80225-0287

This material is from Natural Resource Year in Review--1996, published by the National Park Service, U.S. Department of the Interior, in May 1997 (publication D-1182) http://www2./YearInReview/yir/yr_rvw96/chapter1/demograp.htm
Last Update: 8/20/2002