The United States Is Already Overpopulated

Executive Summary


The United States is already overpopulated in the sense that we are consuming our national ecological resources at an unsustainable rate. Our growing dependence on foreign energy supplies is a prime example. We now depend on foreign imports for 28.8 percent of our energy consumption: two-thirds of our petroleum products and about one-sixth of our natural gas consumption.1 Because of the abundance of our nation's resources, we have long been careless about our level of consumption, but it is the precipitous rise in the U.S. population over the last four decades that has resulted in our outstripping of our national resources. We are living beyond our means and are doing so increasingly as our population expands. This is a serious problem with major implications for future generations.

This imbalance can not be remedied without curbing both population growth and consumption as well as increasing productivity. We must become more sensitive to the issue of consumption of finite, non-renewable resources and to the limits of renewable resources. Reining in population growth requires immigration reduction, and that objective should be at the top of the agenda for policy makers because it is the most immediate and the most amenable to change through public policy.

In 1972, the Presidential Commission on Population Growth and the American Future recommended population stabilization, concluding: “The health of our country does not depend on [population growth], nor does the vitality of business nor the welfare of the average person.” The Commission’s recommendation was based on the 1970 Census finding that the population had reached more than 203 million residents. Since 1970, the U.S. population has added more than 100 million residents, about a 50 percent growth in fewer than 40 years. As the root cause of land and resource shortages, ecological degradation and urban congestion, sustained and growing overpopulation is jeopardizing the natural inheritance we leave for future generations.

The United States has a national environmental policy but no national population policy. As a result, environmental policy decisions are made in a vacuum. By determining the long-term ecological carrying capacity of the United States, Congress would be able to make informed decisions regarding the impact of U.S. population change on achievement of long-term environmental objectives. This report does not attempt to quantify the carrying capacity of the United States; it simply explains how current population growth is damaging the U.S. environment and lowering the average American’s quality of life.

A local example of what should be undertaken at the federal level has been launched in Albemarle County, Va. (Charlottesville) where Advocates for a Sustainable Albemarle Population (ASAP) is promoting a population limit for the county. Its focus is to, “use ‘smart growth’ tools to manage development in the short term, but simultaneously insist that local governments identify an optimal sustainable population size to cap growth in the community, and use this “right size” as a basis for municipal planning decisions.”2 An obvious drawback to dealing with overpopulation at the local level is that the possibility for dealing with the issue of immigration — which ASAP acknowledges accounts for 85 percent of national population growth — is very limited.

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What is Over-population?


National over-population simply means the population of the country in excess of the ability of available resources to sustain it without degrading the environment. The theory that underscores this concept is the population size magnified by both per capita consumption (affluence) and offset by technology determines the environmental impact of that population.

I = PAT: Environmental Impact = Population x Affluence (Consumption & Waste) x Technology

  • Environmental Impact: The impact on biodiversity, natural resources and ecosystems.
  • Population: The total number of people impacting an environment.
  • Affluence: Per capita consumption and the waste generated through resource consumption.
  • Technology: The efficiency with which resources are used and disposed of.

Source: Ehrlich, Paul and Holdren, John. 1971. IPAT, Stanford University.

Nations with high consumption levels generally have large ecological footprints, i.e. environmental impact. Add to the equation a large population with a high level of consumption — as is the case with the United States — and the situation becomes unsustainable. Population growth is steadily diluting the U.S. biocapacity, leaving only about 5 hectares [about 12.4 acres] of productive land available per person. Meanwhile, the steady rise in consumption has increased Americans’ per capita ecological footprint — in part because of our growing dependence on imported energy resources — to more than 9.4 hectares [about 23.3 acres].3 In the last four decades, the U.S. has gone from a positive net ecological surplus of 2.1 hectares per capita to a deficit of -4.4 hectares per capita.4 Another aspect of this same trend into unsustainable consumption is that the U.S. per capita ecological footprint has increased gradually — six percent since 1980 — while per capita biocapacity has decreased rapidly — 26 percent — due to a 30 percent increase in the U.S. population.5

Population Distribution and Regional Overpopulation


In 1933, President Herbert Hoover’s Committee on Social Trends projected that “we shall probably attain a population of between 145 and 150 million during the present century.”6 Because of the unanticipated post World War II “baby boom” and the 1965 change in immigration policy that opened the door to ever-increasing annual admission of immigrants, the Commission’s projection was off by more than 130 million — the U.S. population surpassed 281 million in 2000.

Sixty-three years later the U.S. Census Bureau released its projection for growth in the 21st century. The “middle series” — the most likely scenario — showed a population of about 394 million residents in 2050. That projection was shown by the results of the 2000 Census to be already understated. The latest projection by the Census Bureau (2008) — based on current demographic trends — is for a population of more than 439 million in 2050. Unless we adopt policies that moderate our current demographic trend, we are destined to continue to exacerbate the over-consumption of our fixed and nonrenewable resources.

What is propelling the nation’s rapid population growth? In a word, it is immigration. That is because new immigrants and their U.S.- born children currently account for 75 to 80 percent of our annual population growth. And, that share of population growth due to immigration has been rising along with the rising number of new immigrants. The Pew Hispanic Center researchers estimated in 2008 that given current trends 82 percent of population growth from 2005 to 2050 will result from immigrants and their descendents.7 Much of the rest of the population growth results from continuing ripples from the baby boom and some slight increase in life expectancy. With succeeding generations, those population effects are expected to diminish and we will be left with virtually all population growth resulting from the expansion of immigration.

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Environmental Effects of Overpopulation


  • Agriculture — Forty percent of all U.S. land area is used as productive land or to support agriculture.8 However, this percentage is declining due to suburban development. Population growth contributes to the annual loss of more than three million acres of farmland.9 Furthermore, agricultural production is increasingly dedicated to fuel production rather than food.
  • Biodiversity — Nationwide, an estimated 6,700 species are at risk of extinction.10 Meanwhile, more than 500 known U.S. species are already extinct.11 The human population has now appropriated half of the continental U.S. for its sustenance, leaving native species with increasingly degraded ecosystems.12
  • Energy Usage — Increasing energy consumption is closely correlated to population growth. From 1974 to 2007 the U.S. population grew 41.7 percent while total energy consumption grew 37.1 percent.13 The growing release of greenhouse gases and fuel spills related to supplying the inputs for increased energy consumption degrade species habitat and contaminate waterways used for fishing and recreation.14
  • Forests — Since European colonization, America’s total forest cover has declined by a third.15 Only about five percent of the country’s original old-growth forests remain, while all other present day forest has been previously logged and is thus younger and less diverse.16
  • Land Use — Developed land in the continental U.S. increased 48 percent from 1982 to 2003.14
  • Sprawl — Across America, cities are challenged to cope with the effects of over-population-induced urban crowding and sprawl. Yet cities and localities have limited ability to slow growth through zoning and planning. Only the federal government can lawfully adopt measures aimed at stabilizing the population by curtailing mass immigration.17
  • Water — The average American uses 550,000 gallons of water annually.18 The decline of water levels has coincided with an increase in water pollution. Nationwide an estimated 40 percent of rivers, 46 percent of lakes, and 50 percent of estuaries are too polluted for fishing and swimming.19,20

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Defenders of Population Growth


The Great Ponzi Economy
The argument that population growth is essential for economic growth employs the logic of a Ponzi scheme. It works only if there is endless population growth. Common sense tells us that there are limits to sustainable population growth just as there is a limit to the land area of our country.

The U.S. population is now 307 million residents with an annual average growth rate of 0.975 percent.21 Slightly less than one percent per year seems like a small level of growth, but in fact it is a high level of growth for a population as large as ours. As of July 4, 2009 the U.S. was officially 233 years old, so let’s project what another 233 years of the current rate of population growth would produce. Today’s population (307 million) increased by the current annual growth rate (1.00975) 233 times equals a population of 2,944,205,941 — just shy of three billion people and nearly ten times our current population — and it would not stop there.

We must rethink the assumption that continued population growth is necessary for economic growth. Our economic competitors in Europe and Japan have proved that assumption is false. True increases in per capita wellbeing depend on productivity growth based on technological or organizational innovation, not population growth. At the same time, a growing population reduces the natural resources and land available per person and decreases the nation’s biodiversity, while increasing pollution, traffic congestion, and sprawl. A few economic elites do benefit from overpopulation by skimming a percentage off the labor of an ever-increasing workforce. But, the population growth Ponzi scheme will fall apart - like all Ponzi schemes — because it cannot be indefinitely sustained. The land simply cannot support a continually increasing population — and it is already facing the threat of collapse because the country is already in ecological deficit.

The Population Growth Lobby
The defenders of population growth are almost universally institutional, not individuals. The public is generally concerned about continued population growth.22 The discrepancy between citizen and institutional interests is clear. Individuals benefit from moderate population density, open spaces, and a healthy environment. Institutions benefit from increased membership and large consumer markets and labor pools.

Why does Congress not act to limit mass immigration? As is usually the case with otherwise inexplicable public policy decisions, the answer lies with lobbies. Following is a list of influential special interest lobbies that have successfully lobbied for immigration-fueled population growth.

  • Labor Unions — Labor unions have been losing membership since the mid 1950s.23 From 1996 to 2003 native-born membership declined 6 percent, while foreign-born membership rose 28 percent.24 The AFL-CIO supports amnesty for America’s 12 million illegal immigrants and immigration expansion.25 Recruitment of immigrant workers is seen as a growth opportunity, although an increase in foreign guest workers, which industry wants, does not fit that profile. While the power of the unions may grow with more members, increasing the labor pool through immigration reduces the bargaining leverage of individuals and translates into stagnating or falling wages and working conditions for American workers.
  • Advocacy Groups — Many advocacy groups support immigration increases and amnesty for illegal immigrants, while opposing enforcement measures aimed at denying jobs to illegal immigrants, such as the E-Verify system.26 These groups include “ethnic advocates” such as the National Council of La Raza and the Arab-American Anti-Discrimination Committee. Others with a similar agenda include religious groups, with the Roman Catholic Church — which like the unions is also coping with a membership decline despite a fast rising share of immigrant members — at the forefront. Advocacy lobbies generally promote legislation that benefits the continued growth of their particular constituency.
  • U.S. Chamber of Commerce — “The world’s largest business organization” has long championed cheap labor and open borders. In addition to supporting general amnesty and mass immigration, the Chamber also supports increased immigration and temporary guest worker programs.27 It has made common cause with ethnic advocacy groups in opposing new requirements to use E-Verify to assure jobs go only to legal workers.28

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Several industries promote specific types of immigration. These include:

  • Technology — Companies such as Google, Microsoft, and Verizon promote expansion of the skilled workers program (H1-B visa). The H1-B program increases competition for high-tech jobs, thereby reducing wage pressures. Guest workers also contribute to the ability of employers to hold down payrolls by replacing older and thus more expensive American workers with younger, less expensive and more compliant workers who depend on their sponsor for their work visa.29
  • Hospitality — The service and entertainment industries support expanding non-skilled guest worker (H-2B visa) programs and a general amnesty for illegal immigrants.30 The National Restaurant Association opposes laws implementing the ban on hiring illegal workers including implementation of the E-Verify system.31 Their position is influenced by the industry’s role as one of the nation’s largest employer of illegal immigrants.
  • Agribusiness — Growers, producers, manufacturers and distributors of labor-intensive harvested crops are all deeply invested in maintaining a large supply of cheap unskilled labor. Agricultural employers have lobbied extensively for easing the protections for American workers in the agricultural guest worker program (H-2A visa), and against required use of E-Verify.32
  • Financial — Every additional immigrant is seen as valuable contributor to a growing gross domestic product (GDP), and, therefore, to the financial sector. While official unemployment currently approaches 10 percent nationwide in 2009, the financial sector is lobbying to increase competition for jobs and, thereby, suppress wages further for American workers by expanding the intake of foreign H-1B guest workers to at least 250,000 annually.33
  • Construction — The construction industry was once a stepping stone to middle-class America; today it has become the second largest employer of illegal aliens.34 In addition to benefiting from low wage immigrant labor, the construction and real estate industries welcome the housing demand generated by rapid population growth. The National Association of Realtors views mass immigration as the key to "a long-term strong housing market." 35

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Addressing Overpopulation


Population Growth and Quality of Life
A quality of life index developed by The Economist Magazine found that low population growth correlates closely with a healthy GDP per capita.36 Only five of 20 top ranked nations had annual population growth greater than half of one percent in 2005. On the other hand, 11 of the top-rated 20 nations experienced annual population growth of one-tenth of one percent or lower. The opposite is true of the lowest-ranked 20 nations. Both indicators show a correlation between a low population growth rate and a high-ranking on the index.

Immigration-Stimulated Population Growth
The predominant role of immigration in causing U.S. population growth means that Congress can effectively stabilize the population through a change in immigration policy. Unsustainable growth stems from two policy decisions in Washington — the increase in immigration quotas to record levels since 1965 and the ineffective enforcement of laws designed to deter illegal immigration. The U.S. accepts far more legal immigrants as a percent of our population than do the nations of Europe. As a result, the U.S. population is booming at about one percent per year, while Western Europe has reached stability.

Recognizing that immigration was the dominant contributor to U.S. population growth, President Clinton’s Council on Sustainable Development acknowledged in 1996 that, “reducing current immigration levels is a necessary part of working toward sustainability in the United States.” Since then, immigration has reached never before seen levels and the U.S. population has grown by a 42 million.

A change in U.S. immigration policy would not mean turning our back on cultural and ethnic diversity, but the number of immigrants coming to the U.S. each year must be reduced in order to achieve population stability. Each year nearly 300,000 people emigrate from the U.S. and become permanent residents in other countries. By bringing immigration and emigration into balance the nation can honor its immigrant heritage while stabilizing its population.37 There is no ethical or practical barrier to population stabilization.38 The only barrier is a lack of political will.

As of 2007, the U.S. fertility rate had risen above 2.1, up from a low of 1.74 in 1976.39 The reversal in the birthrate trend involves several factors, but most notable was the growth of immigrants as a percentage of the total U.S. population, increasing from 5.4 percent in 1970 to 12.6 percent in 2008.40 Immigrants on average have higher birthrates than native-born Americans, yet their access to family planning services is restricted by language barriers and their hesitancy to seek government services. Because the birthrate has recently moved above replacement level, it is important not to ignore the large share of births to unmarried, teenaged immigrants.41 Government should be focused on ensuring that all prospective parents have the necessary information to make good choices.

Achieving Population Stability
Fortunately, population growth can be moderated by legislating and executing appropriate immigration policies. It can also be influenced by programs that address natural change (births less deaths) through promoting family planning efforts to decrease unwanted births. But that is unlikely to have nearly as great an impact as reducing the imbalance between immigration (arrivals) and emigration (departures). Population stability requires neither discriminatory immigration policies nor intrusive natality policies. It requires three policy reforms: zero-net immigration, enforcement of current laws combatting illegal immigration, and family planning education.

Preserving the American Dream
The American dream simply cannot be conveyed undiminished to the next generation if we grow to a nation of 500 million residents, let alone a billion or more. It is rooted in the limits of the land’s abundance — and that abundance is being diminished by unsustainable population growth. Americans must now decide what heritage to bequeath to the next generation. A larger population will deprive our children (and ourselves) of the enjoyment of open spaces, biodiversity, and a clean environment and it will jeopardize their standard of living. The time has come for Congress to adopt a population policy that respects the realities governing our environment and quality of life.


September 2009


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  1. "Annual Energy Outlook 2007," Table A1, Energy Information Administration, U.S. Department of Energy.
  2. Jack Marshall, Ph.D., ASAP president, "Organizing for a Sustainable Population at the Local Level," Population Press, Fall 2009 (Vol. 15, No. 3). The ASAP website is at
  3. The Ecological Footprint Atlas 2008, Global Footprint Network,
  4. Global Footprint Network. "United States of America." Country Trends (2005). October 2008. Global Footprint Network.
  5. U.S. Census Bureau. "Table 1. Urban and Rural Population: 1900 to 1990." October 1995. U.S. Census Bureau.
  6. United States. President's Research Committee On Social Trends Records. 1932. Hoover Institution Archives. Stanford, California 94305-6010.
  7. Passel J. S. and D. Cohn. "U.S. Population Projections: 2005-2050." February 11, 2008. Pew Hispanic Center.
  8. Economic Research Service. "State Fact Sheets: United States." U.S. Department of Agriculture (consulted June 2009).
  9. National Resource Inventory. U.S. Department of Agriculture (consulted June 15, 2009).
  10. Cohn, J. P. and J. A. Lerner. "Integrating Land Use Planning and Biodiversity." 2003. Defenders of Wildlife. (consulted June 15, 2009)
  11. Stein, B. A., et al. "Executive Summary." Precious Heritage: The Status of Biodiversity in the United States. Oxford: Oxford University Press (March 2000).
  12. Biodiversity Project. "Getting on Message: Making the Biodiversity-Sprawl Connection." 2000.
  13. Martin, J. "Immigration, Energy and the Environment." Federation for American Immigration Reform. June 2009.
  14. Energy Information Administration. "Table 1. Coal Production and Number of Mines by State and Mine Type, 2007-2006." DOE/EIA 0584 (2007).
  15. O’Malley, R. The State of the Nation’s Ecosystems: Measuring the Lands, Waters, and Living Resources of the United States. The Heinz Center. April 2006.
  16. U.S. Forest Service. US Forest Facts and Historical Trends. U.S. Department of Agriculture. FS-696-M: September 2001.
  17. Report on the Environment. "Urbanization and Population Change." U.S. Environmental Protection Agency. (consulted, June 15, 2009) U.S. Environmental Protection Agency
  18. World Resources Institute. Earth Trends Data Tables. "Water Resources and Fisheries." 2004.
  19. "Our Initiatives: Freshwater Conservation." 2009, The Nature Conservancy.
  20. Stein, J., et al. "River of Renewal: A Vision for Reconnecting Communities to a Living Upper Mississippi River." American Rivers. August 2001.
  21. The World Factbook, "Field Listing: Population growth rate." 2009 est. Central Intelligence Agency.
  22. Jones, J. M. “Majority Says Population Growth is Major Problem for U.S. Future.” Gallup News Service. July 14, 2006. Gallup Poll
  23. Bureau of Labor Statistics. "Trends in Union Membership." U.S. Department of Labor. 2008. MSN Encarta.
  24. Grieco, E. "Immigrant Union Members: Numbers and Trends." Migration Policy Institute. May 2004.
  25. Preston, J. and Greenhouse, S. "Immigration Accord by Labor Boosts Obama Effort." The New York Times. April 13, 2009.
  26. Ruark, E. "Immigration Lobbying: A window into the World of Special Interests." Federation for American Immigration Reform. Jan 2008.
  27. Ibid.
  28. World Resources Institute. Earth Trends Data Tables. "Water Resources and Fisheries." 2004. (consulted, June 15, 2009) World Resources Institute
  29. Op. cit. Ruark, E.
  30. American Hotel and Lodging Association. Press Release. September 11, 2006. (consulted, June 14, 2009) AH&LA
  31. National Restaurant Association. Public Policy Issue Briefs. "Immigration Reform." (consulted, June 16, 2009) National Restaurant Assocation
  32. National Milk Producers Foundation. "NMPF Study Finds Dairy Farms Rely Heavily on Foreign Workers." June 4, 2009. (consulted, June 15, 2009) NMPF
  33. Business Round Table. CEO Survey. "Business Roundtable First Quarter 2008 CEO Economic Outlook Survey Media Conference Call Transcript of Briefing by Harold McGraw III." 2008. Business Roundtable
  34. Passel, J. S. "The Size and Characteristics of the Unauthorized Migrant Population in the U.S." March 7, 2006. Pew Hispanic Center.
  35. National Association of Realtors. "Who Are Today’s Buyers?"(consulted, June 15, 2009)
  36. "The Economist Intelligence Unit’s quality-of-life index," The Economist Magazine, 2005.
  37. Vermonters for a Sustainable Population. "Position and Policy Statements." 2008. (consulted, June 16, 2009)
  38. Cafaro, P. and W. Staples III. "The Environmental Argument for Reducing Immigration to the United States." June, 2009, Center for Immigration Studies.
  39. The Advisory Board Company. "High U.S. Fertility Rate Unusual Among Industrialized Countries, Opinion Piece Says." May 8, 2009.
  40. "Table 1. Nativity of the Population and Place of Birth of the Native Population: 1850 to 1990." Mar 9, 1999, Population Division. U.S. Census Bureau.
  41. Passel, J. and D. Cohn. "Immigration to Play Lead Role In Future U.S. Growth." Pew Research Center.