Population Growth and The Environment: Planetary Stewardship

Population Growth and the Environment: Planetary Stewardship David Pimental Cornell University Introduction During recent decades there has been a dramatic worldwide population increase. Based on current rates of increase of 1.5% per year, the world population is projected to double to more than 12 billion in about 46 years (Population Reference Board, 1996). The world population adds more than a quarter million people daily and this rapid growth is placing enormous pressure on the environment. The United States population doubled from 135 million to more than 270 million during the past 60 years and is projected to double again to 540 million in the next 70 years based on the current U.S. growth rate of 1% per year (United States Bureau of the Census, 1996). China's population is 1.2 billion and, despite the governmental policy of permitting only one child per couple, it is still growing at an annual rate of 1.1% (doubling time of 60 years) (PRB, 1996). India has nearly 1 billion people living on approximately one-third of the land of either the United States or China. India's current population growth rate is 1.9%, which translates to a doubling time of 37 years (PRB, 1996). Together, China and India constitute more than one-third of the total world population. Given the decline in resources, it is unlikely that India, China, and the world population in total will double. In the world today more than 2 billion humans are now malnourished, and this is the largest number of hungry humans ever recorded in history (Neisheim, 1993; Bouis, 1995; World Health Organization, 1995)! Conceivably the numbers of malnourished will reach 3 to 5 billion in future decades. Reports from the Food and Agriculture Organization of the United Nations and the U.S. Department of Agriculture, as well as numerous other international organization further confirm the serious nature of the global food supply (Royal Society and National Academy of Sciences, 1992; NAS, 1994). For example, the per capita availability of world cereal grains, which make up 80% of the world's food supply, has been declining for the past 15 years (Kendall and Pimentel, 1994; Harris,