Questions listed below will help you in reviewing the information on growth of the human population that we discussed in lecture, as well as some of the introductory material. Links within the questions refer you to portions of the lecture notes covering this material; please note, however, that some topics are addressed in several places within the notes and that links are provided only to the primary or original place where the topic is discussed. To review these topics, click on history for notes on the history of human population growth and an introduction to demographic paramenters, and on current for notes on the current status of human population growth.


(1) What are "ecosystem services" and how do we, as humans depend on them?

(2) What is the difference between proximate and ultimate causal factors? Which type of factor (proximate or ultimate) do we usually focus on when trying to solve environmental problems, and why do we tend to focus at that level?

(3) You should understand the fundamental parameters describing population growth --b and d (per capita birth and death rates), r (rate of net reproduction per individual), N (current population size), and K (carrying capacity). How can you calculate the growth rate of a population?

(4) You should understand the difference between exponential and logistic population growth, and should understand the extent to which both do or do not apply to growth of the human population.

(5) What has been the long-term historical pattern of human population growth, and what historical (cultural or biological) factors have caused that pattern?

(6) What is the present trend in growth rate for the global human population, and to what extent do trends vary from nation to nation (general concepts, not specific numbers)?

(7) What is the "demographic transition ?" Speeding passage through this transition is urged by some as a way to stabilize populations rapidly. What is the major alternative school of thought about how population growth rates could be slowed? What aae strengths and waknesses of each approach? Are they mutually exclusive?

(8) You should understand what "replacement level fertility ," "total fertility rate ," and "zero population growth " mean. How are the relationships between these concepts affected by population age structure (e.g., why has China pushed a one-child-per-couple policy?). What is population momentum? How can it be reduced?


Balter, M. 2006. The baby deficit. Science 312: 1894-1897. (Explores causes and consequences of declining fertility rates in various regions of the world and strategies that some governments are taking to avoid "the low fertility spiral." Also discusses reasons for the US having anomalously high total fertility rates compared to other developed nations.)

Bohlen, P.J., S. Lynch, L. Shabman, M. Clark, S. Shukla, and H. Swain. 2009. Paying for environmental services from agricultural lands: an example from the northern Everglades. Frontiers in Ecology and Environment 7: 46 - 55. (Describes a pay-for-environmental services program that would compensate cattle ranchers in Florida's northern Everglades region for providing water storage and nutrient retention on private agricultural lands. Identifies key challenges associated with the initiative.)

Bongaarts, J. 1998. Demographic consequences of declining fertility. Science 282: 419-420. (A lucid discussion of the way that a population's age structure can introduce a big lag between the time that fertility rates fall and the time that population growth stops or slows (re. population "momentum")).

Brown, L. R. 1995. Nature's limits. Chapter 1 in: State of the World, 1995, ed. by L. R. Brown. W. W. Norton and Co., NY. (Examines question of whether we have exceeded Earth's carrying capacity for humans, focusing on sea food catch, water availability, and response to fertilizers as examples. Argues that unsustainability feeds instability in social as well as natural systems. Lots of data on China.)

Brown, L.R. 1999. Crossing the threshold: early signs of an environmental awakening. World Watch March/April 1999: 13 - 22. (Through examining trends in energy use [including alternative energy sources], use of recycled materials, and attitudes towards population growth, Brown concludes that we are on the verge of a new and needed era of environmental awareness. He gives examples of shifts in corporate attitudes, attitudes of the public, and of governments. Mixed in is a dose of alarming statistics, lending fuel to his claim that this change in awareness is coming none too soon.)

Cohen, J.E. 2003. Human population: the next half century. Science 302: 1172 - 1174. (An interesting assessment of various population projections through 2050 - focusing particularly on differences in projections for "rich" and "poor" nations and on likely changes in the percentage of global population living in urban areas and in age structures and their implications. Also discusses major uncertainties with regard to patterns in immigration/emigration and changes in the structure of families as they affect projections.)

Daily, G.C. (ed.) 1997. Nature's Services: Societal Dependence on Natural Ecosystems. Island Press. (A daring attempt to calculate the economic value of ecosystem services. Includes discussion of ecosystem services in general, with specific case studies, historical and philosophical perspectives, and chapters on economic valuation.)

Daily, G.C. et al. (NOTE -- if you were citing this article as a reference for a paper you were writing, you'd provide names [first initial, middle initial, last name] for all authors, rather than using "et al."; See Lutz citation, below, for an example of multiauthor format) 1997. Ecosystem Services: Benefits Supplied to Human Societies by Natural Ecosystems. Issues in Ecology (2), Spring 1997, Ecological Society Of America. (A succinct version of the attempt referenced just above. Availalbe in PDF at

Daily, G. C. and P. R. Ehrlich. 1992. Population, sustainability and Earth's carrying capacity. BioScience 42:761-771. (Attempts to build a framework for estimating population sizes and lifestyles that could be sustained without undermining future generations.)

Dodds, W.K. (and seven other authors; see note about citation format under the second Daily reference, above). 2008. Comparing ecosystem goods and services provided by restored and native lands. BioScience 58: 837-845. (Assesses attempts to restore lands to their natural conditions in terms of the degree to which "restored" lands provide ecosystem services comparable to native lands. Concludes that restoration attempts are worthwhile, but that restored lands do not necessarily provide benefits = to those provided by native lands.)

Ehrlich, P. R. 1968. The Population Bomb. Ballantine Books, NY (An early warning about the dangers of overpopulation, that called public attention to the issue. Facts are dated, but many of the points it raises are current.)

Ehrlich, P. R. and A. H. Ehrlich. 1990. The population explosion. Why isn't everyone as scared as we are? The Amicus Journal. Winter 1990:22-29. (Reviews historical patterns and current trends in human population growth, examines critically the proposition that world hunger is caused by problems of food distribution rather than by too many people. A good example of exploring proximate versus ultimate causes.)

Ehrlich, P.R. and A.H. Ehrlich. 1996. Betrayal of Science and Reason. Island Press. (An excellent review of some of the most critical environmental problems facing the globe today, with emphasis on their connection to growth of the human population. Also provides guidance on how to interpret claims that all is really well with the environment [i.e., guidance on how to interpret claims by the "brown lash," their term for the antienvironmental backlash].)

Engelman, R. 2010. Population, Climate Change, and Women's Lives. Worldwatch Report 183. (A thorough and data-driven exploration of the current status of the three topics mentioned in the title, with discussion of alternative future scenarios and their implications.)

Field, C.B. 2001. Sharing the garden. Science 294: 2490-2491. (Describes another attempt to calculate what fraction of the earth's net primary productivity (NPP) humans approppriate; estimates are close to those given in Vitousek et al. from your readings packet.)

Gatto, M. and G.A. De Leo. 2000. Pricing biodiversity and ecosystem services: the never-ending story. BioScience 50: 347 - 355. (Argues that, while cost-benefit analysis is an important part of decision making, and that monetary values can be assigned to ecosystem services for that purpose, we should also use other tools for decision making that do not rely soley on economic valuations but that are clearly articulated and "transparent." Also suggests that there are dangers in assigning monetary value to such services, as that perpetuates the notion that the environment is simply a commodity to be exploited.)

Goldfarb, T. D. 1989 (ed.) Is population control the key to preventing environmental deterioration? Issue 6 in: Taking Sides; Clashing Views on Controversial Environmental Issues. The Dushkin Publishing Group, Inc., Guilford, CT. (Presents opposing answers to question posed in title; "Yes" by Paul Ehrlich and John Holdren, "No" by Barry Commoner, et al. who argue that technological change rather than population growth has been the chief cause of environmental stress.)

Hardin, G. 1994. Perpetual growth: the next dragon facing biology teachers. American Biology Teacher 56:222-225. (A carefully worked out analysis of why ecologists argue that perpetual growth in anything is neither desirable nor achievable and why economists tend to argue the reverse.)

Hvistendahl, M. 2010. Has China outgrown the one-child policy? Science 329: 1458-1461. (A useful review of the history of China's one-child policy and treatment of reasons for some Chinese demographers arguing that it is time to relax the policy.)

Losey, J.E. and M. Vaughan. 2006. The economic value of ecological services provided by insects. BioScience 56: 311 - 323. (An attempt to estimate the dollar value of services provided by wild insects [as opposed to domesticated species such as honey bees] in agriculture and for wildlife [and hence for recreation]. Even though a limited number of services were estimated, the annual value appears to be close to $57 billion per yr for the US.)

Lubchenco, J. 1998. Entering the century of the environment: a new social contract for science. Science 279:491-497. (OSU's own Jane Lubchenco argues that, given the pressing nature of environmental problems, scientists must commit to work on the most pressing problems of the day in proportion to their importance, in exchange for receiving public funding for the work. New fundamental research and transfer of information resulting from that work to policy- and decision-makers is called for.)

Luick, G.W. and many others. 2009. Quantifying the contribution of organisms to the provision of ecosystem services. BioScience 59: 223 - 235. (An attempt to offer a coherent conceptual framework for synthsizing the latest developments in ecosystem serive research, and direct future studies at various levels of biological organization. Uses examples from the literature to illustrate the approach and to highlight gaps in knowledge.)

Lutz, W., B.C. O'Neill, and S. Scherbov. 2003. Europe's population at a turning point. Science 299: 1991 - 1992. (An insightful analysis of the joint and individual effects of age of child bearing and TFR's on population trends for Europe. We're used to talking about "population momentum" as something that causes population growth, whereas Europe faces "negative momentum!" Assesses implications for Europe's future.)

Nelson, E. and many others. 2009. Modeling multiple ecosystem services, biodiversity conservation, commondity production, and tradeoffs at landscape scales. Frontiers in Ecology and the Environment 7: 4 - 11. (Uses a model to precit changes in ecosystem services, biodiversity conservation, and commodity production levels, focusing on the Willamette Valley of Oregon!! )

Population Reference Bureau. This organization publishes a variety of books, pamphlets, and posters on population issues, including the poster-sized World Population Data Sheet. This data sheet is updated yearly and gives data on 16 demographic variables for 175 countries. Available from PRB, 777 14th Street N.W., Washington, D.C. 20005 or through their web site:

Population Reference Bureau. 2004. Transitions in world population. PRB Volume 59. (I put a link to this article on the Course Documents section of the Blackboard site. I encourage you to look it over as it deals with many of the same issues re. human population that we'll discuss in class - demographic transition, patterns of change in total fertility rates, and so on.)

Pulliam, H.R. and N.M. Haddad. 1994. Human population growth and the carrying capacity concept. Bulletin of the Ecological Society of America September 1994. 141-157. (Provides a review of the development and use of the carrying capacity concept in ecology, and then reviews and discusses past and current attempts to apply it to the human population of Earth.)

Science. 2011. A special section of Science magazine devoted to exploring human population dynamics and their implications. Includes many great articles - too many to itemize here! See pages 539 - 594 in this issue.

Simon, J. L. 1980. Resources, population, environment: an oversupply of false bad news. Science 208:1431-1437. (Argues that resources are not becoming limited, pollution is not increasing, and more people is better.)

Westoff, C. F. 1986. Fertility in the United States. Science 234: 554-559. (An account of historical and fairly recent fertility in the U.S. -- while 1986 may seem long ago, per capita fertility rates haven't changed all that much since then!)

UNFPA 2009. State of World Population 2009. Published by the United Nations Population Fund. (Tremendous compilations of data on demographic, social and environmental factors for nations of the world, and text that focuses on the subtitle: "Facing a changing world: women, population and climate.")

Click "Navigate" for a general reminder on how to move within and among these documents, or click on the "Contents" box at the bottom of this page to return to the master table of contents for this site.

Page last updated Oct. 18, 2013. For comments or questions, contact Patricia Muir by clicking here: (