Population and Environment
With an annual growth rate of over 1 percent, more than 70 million people are currently being added to the world's population each year. In the last 40 years, the world's population has doubled from 3 to 6 billion. The high proportion of young people now entering their child-bearing years worldwide guarantees that population growth will continue at a rapid pace for some time.
Population growth taxes the earth's natural systems. Forests and wetlands disappear so that people can grow more food. Water becomes scarce as it is diverted to urban areas and agriculture. Greenhouse gas concentrations increase as more and more people use greater quantities of fossil fuels.
Human Population and Forests
The accelerating loss of the world's forests presents one of the major environmental challenges of the next century. The growth of the human population—from a few million people in prehistory to 6 billion today—looms large among the factors contributing to this loss. Yet many analyses of forest loss despair that population growth is an inevitable force that must be reckoned with but cannot be influenced. This report challenges that view. Its purpose is not only to examine population's role in forest loss, but also to highlight the value of population policies that simultaneously improve human well-being and brighten the prospects for conserving the world's remaining forests.
WHY WE NEED FORESTS
Forests are a vital resource for many of the world's people. They provide societies with a wide array of goods and services, sustain millions of plant and animal species, maintain air and water quality on which human life and health depend, and are important regulators of the planet's climate
UNDERSTANDING FOREST LOSS
Spread across six continents, forests cover 27 percent of the world's land area—roughly 35 million square kilometers. The world's developing regions contain 57 percent of global forest cover, with the remaining 43 percent found in developed countries. Just four countries—Russia, Brazil, Canada, and the United States—contain half of the world's current forests (FAO 1997).
Half of the world's original forests have disappeared since the end of the last Ice Age. More forest was cleared from 1850 to the present than in all previous history, and the rates of deforestation have been highest in the last few decades. The ratio of forested land to human beings has dropped steadily as population has grown and the world's forests have retreated (See Figure 2). The amount of forest cover avaBio-Diversity?ilable to each person, a key measure of forest resource pressure, has declined globally by 50 percent since 1960 to 0.6 hectares (1.5 acres) per person.
Population and the Future of Renewable Water Supplies: Sustaining Water, Easing Scarcity
Of all the planet's renewable resources, fresh water may be the most unforgiving. Difficult to purify, expensive to transport, and impossible to substitute, water is essential to food production, to economic development, and to life itself. There are currently more than 430 million people living in countries considered "water stressed." Population Action International (PAI) projects that by 2050, the percentage of the world's population living in water stressed countries will increase by at least threefold.