Does the earth have a population limit?

Question

Can the earth only support, say 10 billion people? Or is the number less or more?

No long answers accepted as best. Blah, Blah, Blah...

Invention drives population, so you will have to decide the best answer.

Answer 1

We already crossed the limit for ideal life. Hence the imbalance that we see these days. Maybe we should seriously consider Mars (which am eating right now).

Answer 2

Sadly I'd say now. We have limited resources , in the next few generations global warming will have a far worse detrimental effect than whats happening now. There are too many people and not enough life sustaining product available anymore.

Answer 3

There is no definite limit, but the resource supply is obviously finite. Too many people would have people living less well than if there were a more suitable number.

Answer 4

Yes, it's called "When we run out of resources" Oil is a big one.

Answer 5

you can only make estimates based on certain assumptions of human activity. those assumptions will always be open to question.

Answer 6

not sure, but ppl die n ppl born...which keeps the population stable
so don worry :)

Answer 7

once we run out of resources and habitable land, its all going downhill from there...

Answer 8

Everything has it's limits.

Answer 9

Based on the present growth rate of 1.5% per year, the population is projected to double in approximately 46 years (PRB. 1996. World Population Data Sheet. Washington, DC: Population Reference Bureau.)

Because population growth can not continue indefinitely, society can either voluntarily control its numbers or let natural forces such as disease, malnutrition, and other disasters limit human numbers.

Increasing human numbers, especially in urban areas, and increasing food, water, air, and soil pollution by pathogenic organisms and chemicals, are causing a rapid increase in the prevalence of disease and number of human deaths. Currently, food shortages are critical, with more than 3 billion humans malnourished worldwide -- the largest number and proportion ever. An estimated 40,000 children die each day due to malnutrition and other diseases (WHO, 1992).

Clearly, human numbers can not continue to increase indefinitely. Natural resources are already severely limited, and there is emerging evidence that natural forces already starting to control human population numbers through malnutrition and other severe diseases. More than 3 billion people worldwide are already malnourished, and 3 billion are living in poverty; grain production per capita started declining in 1984 and continues to decline; irrigation per capita declined starting in 1978 and continues; arable land per capita declined starting in 1948 and continues; fish production per capita started declining in 1980 and continues; fertilizer supplies essential for food production started declining in 1989 and continues to do so; loss of food to pests has not decreased below 50% since 1990; and pollution of water, air, and land has increased, resulting in a rapid increase in the number of humans suffering from serious, pollution-related diseases.

Fifty-eight academies of science, including the U.S. National Academy of Sciences, point out that "Humanity is approaching a crisis point with respect to the interlocking issues" of population, natural resources, and sustainability (Population Summit of The World's Scientific Academies. Washington, DC: National Academy of Sciences Press.
NAS, 1994, p. 13). The report points out that science and technology have a limited ability to meet the basic needs of a rapidly growing human population with rapidly increasing per capita demands. Unfortunately, most individuals and government leaders appear unaware, unwilling, or unable to deal with the growing imbalances between human population numbers and the energy and environmental resources that support all life. The interdependence among the availability of life-supporting resources, individual standard of living, the quality of the environment, environmental resource management, and population density are neither acknowledged nor understood. Although we humans have demonstrated effective environmental conservation in certain cases (e.g., water), overall we have a disappointing record in protecting essential resources from over-exploitation in the face of rapidly growing populations .

According to experts in the College of Agriculture and Life Sciences Cornell University, the optimum population for the Earth is 2 billion people.

Dr. John Bongaarts, a vice president in the policy research division of the Population Council, has considered these and other factors in predicting that the world is only halfway through a broad population expansion that won't likely end until 2100, when global numbers could stabilize around 10 billion. "In Africa, half the population is under 18," he says, "so the birth rate will remain very high. Fertility is falling everywhere, but the numbers are still 50 percent higher than what they would need to be for population stabilization to occur any earlier. In the developing world, overall fertility has declined from six to three, but it would have to decline even further--to two--for the projections to change. A third factor is that death rates are falling. Both nutrition and sanitation are improving, so people are living longer."

One in six women, 230 million worldwide, is denied the birth control methods she would use if it were available to her, usually for reasons of poverty, reports UNFPA. This access problem is behind the gap that exists between ideal and actual family size in many countries. In the African country of Burundi, for instance, women want 5.4 children and have 6.4; in Bolivia, they want 2.7, but have 4.6.

Obviously, family planning assistance to the developing world would make a huge difference in population size. But at this crucial time, international aid to this part of the world is declining, the result of what Population Action International's Sally Ethelston calls "the lack of a post-Cold War rationale for global engagement."

Even if population does continue to increase dramatically, the optimists at conservative think-tanks like the Cato and Hudson Institutes think the modern miracle of genetic engineering and ever-increasing farm yields will meet the global food challenge. The book World Food Outlook, cited by some of these activists, predicts confidently that "global food production will continue to increase faster than consumption."

Lester Brown of the Worldwatch Institute draws exactly the opposite conclusions. Although he acknowledges rising grain yields, he thinks those gains will soon reach a finite plateau. "The slower rise in world grainland productivity during the 1990s may mark the transition from a half-century dominated by food surpluses to a future that will be dominated by food scarcity," he says. And food scarcity is just part of the problem, says Worldwatch. It also documents declining fish harvests in most major fishing grounds, and an accelerating erosion of the natural resource base, from forests to fossil fuels. In addition, the Johns Hopkins University School of Health recently reported that 2.8 billion people could be facing severe water shortages by 2025.

Does the Earth have a "carrying capacity" beyond which the human population will suffer drastic consequences? Population experts like Garrett Hardin and Paul Ehrlich say that we've already exceeded it, while the late Professor Julian Simon refused to acknowledge any limits. Joel Cohen points out that demographers' estimates of carrying capacity have varied widely over the years. In 1891, British scientist E.G. Ravenstein published a paper in which he confidently extrapolated that the "total possible" population of the Earth was just under six billion, the figure we will reach this year. But Australian economist Colin Clark, writing in 1967, thought the Earth could feed 157 billion people, though his calculations, based on the theoretical availability of arable land, seem rather naïve.


At this late date, family planning should no longer be controversial," says the Population Council's Bongaarts, who nonetheless thinks it will continue to be. He thinks political realities will cause population to peak at 10 billion by the middle of the next century, then level out. It's not a happy scenario. Civilization may not collapse, as some pundits, including the authors of the influential book Beyond the Limits, predict. The Earth's carrying capacity is not a fixed wall, but more a zone of accelerating peril for the human race. "There's no question the environment and our quality of life will be much better off if we never reach 10 billion," Bongaarts says. "It will mean a lot of trouble and a lot of headaches." Add to that a dramatically diminished environment, and a world of lowered expectations for billions of young people.