Population and the Environment

The link between population growth and environmental impact seems obvious at first glance: more people consume more resources, damage more of the earth and generate more waste. However, the larger picture is more complex—the greatest environmental threat comes from both the wealthiest billion people, who consume the most and generate the most waste, and from the poorest billion, who may damage their meager resource base in the daily struggle to avoid starvation.

· High impact nations. High consumption, industrialized nations do much greater environmental damage than developing nations. An American’s environmental impact is 30 to 50 times that of the average citizen of a developing country such as India. Per capita municipal waste grew 30% in developed nations since 1975 and is now two to five times the level in developing nations. (Source: United Nations Development Programme, Human Development Report 1998, New York, 1998, Web version available at http://www.undp.org/hdro/98.htm

· Global biodiversity at risk. Wild species are becoming extinct 50 to 100 times faster than they naturally would without the impact of rapid population growth and increased population density in many countries. One in four vertebrate species is on the verge of extinction or already extinct; 25% of mammals, 11% of birds, 20% of reptiles, 25% of amphibians and 34% of fishes are currently threatened. (Source: Worldwatch Institute, Earth Day Report Card, Washington, DC, March 2000, Web version available at http://www.worldwatch.org/mag/2000/00-2.html; and Population Action International, Nature’s Place: Human Population and the Future of Biological Diversity, Washington, DC January 2000, Web version available at http://www.populationaction.org/pubs/biodiv00/biodiv_index.htm)

· Forest depletion. More forest has been cleared since 1850 than in all of human history. The loss is concentrated in developing countries—both to meet the demand for wood and paper by the industrialized world (the 20% of people in the world’s highest-income countries consume 84% of all paper products) and because wood is a main source of energy for nearly 3 billion people (90% of wood harvests in Africa, 80% in Asia and 70% in Latin America are used for fuel). (Source: United Nations Development Programme, Human Development Report 1998, New York, 1998, Web version available at http://www.undp.org/hdro/98.htm; and Population Action International, Forest Futures, Washington, DC, 1999, Web version available at http://www.populationaction.org/why_pop/forest/forest_index.htm)

· Contributions to the “greenhouse effect.” Most researchers attribute global warming and disruption in weather patterns to increases in the Earth’s carbon dioxide levels. Largely from deforestation and the burning of fossil fuels, the global emission of carbon dioxide has quadrupled since 1950. The atmosphere now has 30% more CO₂than it did at the beginning of the Industrial Revolution. The richest fifth—the 20% of the world’s population living in the highest income countries—produce 53% of all carbon dioxide emissions, while the poorest fifth account for only 3% of CO₂ output. (Source: United Nations Development Programme, Human Development Report 1998, New York, 1998, Web version available at http://www.undp.org/hdro/98.htm)

· Water scarcity. Per-capita water consumption is rising twice as fast as world population. At least 300 million people live in regions that already have severe water shortages; by 2025, the number could be 3 billion. Some 20 countries already suffer from water stress, and water’s global availability has dropped from 17,000 cubic metres per capita a year in 1950 to 7,000 in 1998. In the United States, our water is increasingly being polluted by livestock—the U.S. Fish and Wildlife Service identifies livestock waste as the principal pollutant of 1,785 bodies of water in 39 U.S. states. (Source: Paul Simon, Tapped Out, Welcome Rain Publishers, New York, October 1998; United Nations Development Programme, Human Development Report 1998, New York, 1998, Web version available at http://www.undp.org/hdro/98.htm; and Population Action International, Nature’s Place: Human Population and the Future of Biological Diversity, Washington, DC, January 2000, Web version available at http://www.populationaction.org/pubs/biodiv00/biodiv_index.htm)