Cornell report accesses the carrying capacity of the Earth's resources and how these resources relate to the requirements of a rapidly growing human population

CNN, September 24, 1999

World population is expected to hit 6 billion in October and that number is predicted to double in less than 50 years. That means "12 billion miserable humans will suffer a difficult life on Earth by the year 2100," according to a report from Cornell University - that is, unless population reduction practices are determined and sound resource management policies are implemented. Entitled, "Will Limits of the Earth's Resources Control Human Numbers?" the report accesses the carrying capacity of the Earth's resources and how these resources relate to the requirements of a rapidly growing human population. The report was published this month in the premier issue of the journal Environment, Development and Sustainability. "Of course, reducing population and using resources wisely will be a challenging task in the coming decades," says David Pimentel, lead author of the report. "It will be much more difficult," Pimentel says, "to survive in a world without voluntary controls on population growth and ever-diminishing supplies of the Earth's resources." Because population growth cannot continue indefinitely, the report suggests that society can either voluntarily control its numbers or let natural forces such as disease, malnutrition and other disasters limit human numbers. Among the key findings of the report are:

* More than 3 billion people worldwide are already malnourished and living in poverty.

* The quantity and quality of arable land, water, energy and biological resources determine the current and future status of the support services for human life.

* Between 1960 and 1997, the per capita availability of freshwater worldwide declined by about 60 percent. Another 50 percent decrease in per capita water supply is projected by the year 2025.

* The average per capita world cropland now is only 0.27 hectares, or about half the amount needed to provide a diverse, healthy, nutritious diet of plant and animal products, according to industrial nation standards.

* In addition to limitations due to population increases, high per capita consumption levels in the United States and other developed nations also put pressure on natural resources. For example, each American consumes about 50 times more goods and services than the average Chinese citizen.

* Worldwide, more than 10 million hectares of productive arable land are severely degraded and abandoned each year . Moreover, an additional 5 million hectares of new land must be put into production each year to feed the nearly 84 million humans annually added to the world population.

* Energy use has been growing even faster than world population growth. From 1995 to 2015, energy use is projected to increase at a rate of 2.2 percent (doubling every 32 years) compared with a population growth rate of 1.5 percent (doubling every 47 years)

* The world supply of oil is projected to last approximately 50 years at current production rates.

* As populations increase in size, risks to health and productivity grow as well, especially in areas where sanitation is inadequate. Human deaths due to infectious diseases increased more than 60 percent from 1982 to 1992.

The report points out that "if the whole world agreed on and adopted a policy that only 2.1 children were born per couple, more than 60 years would pass before the world population finally stabilized at approximately 12 billion." On the other hand, "a population policy ensuring that each couple produces an average of only 1.5 children would be necessary to achieve the goal of reducing the world population from the current 6 billion to an optimal population of approximately 2 billion. If this policy were implemented, more than 100 years would be required to make the adjustment to 2 billion people." "With a democratically determined population policy that respects basic individual rights, with sound resource-use policies, plus the support of science and technology to enhance energy supplies and protect the integrity of the environment," the report concludes, "an optimum population of 2 billion for the Earth can be achieved." Then the fortunate 2 billion will be free from poverty and starvation, living in an environment capable of sustaining human life with dignity, the report suggests, adding a cautionary note: "We must avoid letting human numbers continue to increase and surpass the limit of Earth's natural resources and forcing natural forces to control our number by disease, malnutrition and violent conflicts over resources," the report says.

This page was last updated on September 05, 2006 at 10:26 am and is maintained by webmaster@math.rutgers.edu.

For questions regarding courses and/or special permission, please contact mclausen@math.rutgers.edu.

For questions or comments about this site, please contact help@math.rutgers.edu.