INDEX - DEVELOPMENTwww.islandbreath.org ID#0502-04
SUBJECT: SUSTAINABILTY & GROWTH
SOURCE: JUAN WILSON email@example.com
POSTED: 19 APRIL 2005 - 9:30pm HST
Response to Garden Island editorial letter
image above: "Overpopulation" by John Pitre at www.progressiveart.com/pitre_overpopulation.htm
by Juan Wilson 19 April 2005
A letter in the Garden Island today bemoans the high cost of housing on Kauai and suggests a solution: abandon planning and zoning requirements and start building the cheapest housing we can on “marginally useful agricultural land”.
In conjunction with the housing the writer sees a need to build more commercial operations so that people will have jobs. He mentions “high tech” jobs at the PMRF and seed (genetically modified organism) research on the westside as the kind of jobs we need more of here. The fact of the matter is that there are only a handful of those jobs available. The reality is that the bulk of employment in the suburban Kauai the writer desires will be minimum wage service jobs for corporate franchises. That is what is happening on the mainland.
Whether the writer knows it or not, the solution he is advocating will accelerate population growth and development on Kauai as a means to what he hopes will be a better life. Did not the pre-contact Hawaiians have more rewarding lives with stoneage technology?
This “solution” - unrestricted growth and resource depletion - if sustained, has been proven to be a formula for disaster in any civilization that has tried it. Many historians and anthropologists have come to realize that unfettered population growth and exhaustion of resources has been the downfall of human civilizations that have not been conquered by others or the victim of catosrophic natural disaster. It is likely that cultural and financial support from the mainland USA that sustains the current consumer driven economic model will be reduced over time. Everywhere people will have to be more self reliant and be thinking about long term solutions to big problems. Without a plan for a sustainable population and use of our resources we here on Kauai face a grim future.
On the mainland, once things got crowded and all screwed up, there was always another indian tribe to the west that we could be displace affording the us another fresh start; and, unfortunately for us, Hawaii is as far west as that game goes. There is no more “west”. So in a place that is as isolated as Hawaii,with finite resources, starting over after “screwing up” with a huge population will come only after massive economic collapse with human suffering on a biblical scale.
On the other hand, with thoughtful planning we should do better than many other places with fewer resources and greater density. In the next generation places like Los Vegas and much of the urban southwest will face staggering problems with high poplations experiencing water and food shortages.
In some ways we may be seeing a second coming of the survivalism that flourished in the 1970’s. After the manipulated OPEC oil crisis in 1973-74. At that time there was a burst of interest in survivalism; people put 100 pound bags of rice under their beds, bought guns and horded gold. That will be just a dress rehearsal for what will play out if there is a real crisis with the availability of oil and thus food.
Many diverse people seem to have an intuitive sense of near future apocolypse. Some, christian evanagists believe “the end times are coming” and are waiting for the Rapture. Some envionmentalists see nature in retreat everywhere, while secular humanists worry about shortages of cheap energy and food. This sense of something gone “wrong” in itself may be a reason for a real estate boom in Hawaii. Where would you want to be when the lights go out in Los Vegas and there is nothing left in the the freezers? Surfin’.
That does not mean we should just lay down and let the mainland madness overwhelm us with franchized filled plazas overrun with smoking SUV’s. As the bumper sticker says, “Slow down! This ain’t the mainland!”
The U.S. Bureau of the Census' current population projections indicate that before 2020 (the culminating year of the Kauai General Plan) there will be an additional one billion people on earth with a total of over 7.5 billion alive. That's four times the human population when I was born at the end of World War II.
SUBJECT: SUSTAINABILTY & GROWTH
SOURCE: KEN TAYLOR firstname.lastname@example.org
Neighborhood Ecological Footprint
28 March 2005 - 9:30am
Is Your Neighborhood Sustainable?
by Marty Kraft
Environmental problems are often very difficult to see. They are even more difficult to prove beyond a shadow of a doubt. The Ecological Footprint is a tool that can help us see a little more clearly our effect on our planet.
Here I focus on my own neighborhood to bring environmental awareness home to where we live. It was delivered with the neighborhood’s newsletter. Other neighborhoods or cities are invited to use this article as an educational model for newsletters in their own communities.
Mathis Wackernagel and William Rees have written a book, "Our Ecological Footprint: Reducing Human Impact on Earth" that puts carrying capacity back on center stage of the international development debate.
Using Rees' "ecological footprint" concept and figures from Wackernagel’s web site, Ecological Footprints of Nations this article shows just how much of the Earth's land and water area it take to support each person in the 49/63 Neighborhood.
Sustainability - Central to their work is the concept of sustainability - “living in material comfort and peacefully with each other within the means of nature.” Implied in living within the means of nature is that we of the present time don’t ruin nature’s balance and bounty for our children. Sustainability also implies that we live on renewable resources not on fossil fuels that will run out in the foreseeable future.
An Ecological Footprint - An ecological footprint includes the land used to supply all our energy needs, the land used by all the roads, buildings, parking lots, etc. that we depend on, the land used to grow our food, the forest land providing us with wood and paper and the land necessary to dispose of our waste. Drawing from readily available statistics, Our Ecological Footprint attempts to show how much land area our life style requires now and also how much land area we would use if we lived sustainably. Since the statistics used are collected from the whole country the footprint we see turns out to be an average American’s footprint. Each person would then have to evaluate the various factors in their own lives and adjust up or down from the average.
According to the Footprints of Nations the ecological foot print of one average American is 10.3 hectares or 25.45 acres. That is five city blocks plus about two lots (using 5 acre blocks divided into 24 lots). That is how much land it takes to supply all the energy, food, paper, building materials, and consumer goods to keep one average person living the life to which he or she has grown accustomed. By contrast the ecological footprint of average world citizen is 2.8 hectares or 6.92 acres. That is one city block plus about three lots. In India the average person uses about 1.98 acres. That means that about nine city lots supplies all that the average Indian survives on.
If everyone on our planet used as many resources and created as much waste as the Average American, we would require four and two thirds Earths to sustain us.Our Neighborhood’s Footprint Let’s apply the ecological footprint idea to our neighborhood. In the 49/63 Neighborhood we have approximately 8,000 residents.
Assuming that we are all average Americans, (which we are not) each one of us requires 25.45 acres of land to support our lifestyle. Multiplying by the number of our residents we find that it takes 302,600 acres or 318 square miles of land area to support our neighborhood. That is a square with 17.8 miles per side. A circle with 318 square miles would have a radius of approximately 10 miles. A circle whose center is at 55th and Rockhill would include Swope Park, the Sports Complex, Bartle Hall, Antioch Park in Kansas and Bannister Mall. The land we actually live on in the 49/63 neighborhood is about 1.44 square miles.
Kansas City’s Footprint - Kansas City, Missouri takes up about 320 square miles. Our footprint is 436,000 individuals times 25.45 acres, or 10,096,200 acres or 17,338 square miles. That is a square with 131.6 miles on a side or a circle with a radius of 74.3 miles. The circle would include St. Joseph, Cameron, Marshall and Clinton in Missouri and 18 miles beyond Topeka in Kansas. If you look at the population of the greater Kansas City area which was in 1990, 1,582,875 the foot print would extend to Manhattan, KS on the west, Lake of the Ozarks to the southeast and well inside of the Iowa state line to the north.
A similar circle drawn around the St. Louis area would easily overlap the circle drawn around Kansas City. This doesn’t account for the land needed to support the people in all the towns and farms outside the two metropolitan areas.
To give us an idea of what the human carrying capacity of the land is let’s try to estimate how many American Indians the land we inhabit supported. William Cronin in his book Changes in the Land, Indians Colonists, and the Ecology of New England estimates that the crop raising Indians of southern New England had a population density of 2.87 persons per square mile. Assuming that the land in Kansas City is similar to the land in southern New England, the land within the boundaries of the 49/63 Neighborhood Coalition would support slightly over four persons living as American Indians did who used agriculture and stored food for the winter. In comparison the land occupied by the 49/63 Neighborhood Coalition now has approximately 5,555 residents per square mile.
Consequences - It seems there are two groups of issues to look at. The fairness or justice of this situation and the problems that arise because of the imbalance. Most people in America value justice. I find it disturbing that I am a part of this injustice. We have the largest military budget in the world. How much of our military need arises to make sure that we get the resources to live at our present level of convenience? Illegal immigration is a growing political issue. The ecological footprint of the people of Mexico is 6.42 acres per person with only 3.46 acres of ecologically productive land per person. If you were afraid your children would starve wouldn’t you consider risking illegal immigration?
The social problems that arise out of the fairness or justice issue are but child’s play when you consider the consequences of overshooting the carrying capacity of the Earth. When the fossil fuel runs out if we don’t have methods in place of living sustainably for the level of population we have, literally billions of men, women and children will die. Can you imagine the wars and suffering that will occur as countries compete for the meager resources?
Will this happen in our lifetime, our children’s or our grandchildren’s. We don’t know. We seem to be trying to export our lifestyle and consumer products as fast as we can, everywhere on Earth. The more over consumption the faster the crisis approaches. Earth’s support system could falter due to imbalances humans have created by our activities. We might consider that that crisis has already begun with famine in Africa due to climate change or with increases of children with lung disease in Los Angeles.
So what can we do? We can begin by consuming less, raising some of our own food, adjust our work activities so that they are sustainable and make solving this problem part of our daily responsibility.
We really don’t know if our cities can become sustainable. Will our neighborhoods work as fossil fuel diminishes? It’s time we begin doing our research and development while we have fossil fuel to power it. Its time to try things and see what will work. When the crunch arrives it will be too late for anything but blind reaction.
Block Centered Sustainable Community Building - The Heartland All Species Project has been working for three years on Block Centered Sustainable Community Building. That might be defined as getting to know your neighbors and working together to keep the block safe and economically and environmentally healthy. In addition to the issues most neighborhoods focus on, the environmental perspective asks us to think in terms of global systems and direct our local actions accordingly. The block-based component comes about in the attempt to wean ourselves from the automobile. Not only is the automobile a serious environmental problem, but our total acceptance of it has really hurt neighborhoods. With the use of the automobile we can fulfill all our needs without ever having to talk to a neighbor. Huge malls with acres of parking have put most of the mom and pop neighborhood stores out of business. We probably won’t see our neighbors at the mall and mall owners don’t have much reason to contribute to our neighborhood as mom and pop did.
The smallest social unit is the family or the household. Sometimes households are traditional “families”. Other times they’re not. Way back when, our ancestors lived in extended family groupings, or tribes. We all relied on each other for food, protection, education and recreation. Even though we live in modern cities we still have some needs to have the support of our tribal community. But we don’t have closely related people to work with. We have city blocks with a diversity of genes and values. As we feel the grip of energy and food prices go up as they surely will. We will be put in situations where we will have to learn to share to a much greater degree than we do now. At a time when companies are moving away from responsibility for the well being of their employees and the communities that support them, it might be a time for us to get to know each other, to form neighborhood groups that reinvent employment. Perhaps we could form cottage industries of several neighboring cottages. How many of our needs can be supplied by neighbors, eliminating the need to travel across the city?
A year ago when we had five or six garage sales on our block there was a buzz of excitement in the air on Saturday morning. Neighbors were shopping with neighbors. Some neighbors went together for the sales. People got to know each other better. A number of other block residents are ordering food from a natural foods warehouse. In the process they talk to each other a couple of times per month. On another block four households share their yards by gardening together.
At a time when cynicism seems to be a national disease and mistrust prevents us from looking each other in the eye, we have forgotten the supportive feelings that community can bring. Perhaps we remember. Maybe we’re afraid that reaching out to help or for help is a thing of the past. I know how powerful the support and caring of a group can be. In graduate research on encounter groups I found that group members discovered a sense of community that made them come alive. Many did not want to go home. It is not easy to maintain that level of trust but it is possible. Why not?
What About Your Block? - Each one of us can take some small step to improve community relations on our block. Block parties, open houses, shared gardens, even throwing your neighbor’s newspaper on the porch when they are out of town is a step in that direction. We will have to be patient in building community. Community takes months, even years, to build. Trust must be developed and that takes time.
If there is some way that you would like to reach out to your immediate neighbors, some idea you have, and you would like to get an opinion of how it might work please call. I have been thinking about this for a long time. I have passed out flyers on my block for three years and organized several projects. Some worked and some didn’t. I offer my help to you but I also really need your thoughts, suggestions and help. Have you been part of something on your block that worked? Would you like to meet with others who are interested in building strong blocks?
Please give me a call at (816) 361-1230
My address is 5644 Charlotte, Kansas City, MO 64110.
email me or write your comments on the All Species Forum at http://www.allspecies.org/bbs1/.
How to do a block Earth Day
49/63 EcoKids program
Ecological Footprints of Nations http://www.ecouncil.ac.cr/rio/focus/report/english/footprint/
"Our Ecological Footrint: Reducing Human Impact on Earth”, by Mathis Wackernagel and William Rees. Gabriola BC and Philadelphia, PA: New Society Publishers (1996).
SUBJECT: SUSTAINABILTY & GROWTH
SOURCE: KEN TAYLOR email@example.com
VALUING THE EARTH: Economics, Ecology, Ethics
25 March 2005 - 9:30am
For better or worse, the future of the earth is in our hands
VALUING THE EARTH: Economics, Ecology, Ethics
by Herman E. Daly and Kenneth N. Townsend published in 1993
ISBN 0-262-54068-1 MIT Press 800-356-0343 or 617-253-2884 [p. 267]
Sustainable Growth: An Impossibility Theorem
Impossibility statements are the very foundation of science. It is impossible to: travel faster than the speed of light; create or destroy matter-energy; build a perpetual motion machine, etc. By respecting impossibility theorems we avoid wasting resources on projects that are bound to fail. Therefore economists should be very interested in impossibility theorems, especially the one to be demonstrated here, namely that it is impossible for the world economy to grow its way out of poverty and environmental degradation. In other words, sustainable growth is impossible.
In its physical dimensions the economy is an open subsystem of the earth ecosystem, which is finite, nongrowing, and materially closed. As the economic subsystem grows it incorporates an ever greater proportion of the total ecosystem into itself and must reach a limit at 100 percent, if not before. Therefore its growth is not sustainable. The term "sustainable growth" when applied to the economy is a bad oxymoron—self-contradictory as prose, and unevocative as poetry.
Challenging the Economic Oxymoron
Economists will complain that growth in GNP is a mixture of quantitative and qualitative increase and therefore not strictly subject to physical laws. They have a point. Precisely because quantitative and qualitative change are very different it is best to keep them separate and call them by the different names already provided in the dictionary. To grow means "to increase naturally in size by the addition of material through assimilation or accretion." To develop means "to expand or realize the potentialities of; to bring gradually to a fuller, greater, or better state." When something grows it gets bigger. When something develops it gets different. The earth ecosystem develops (evolves), but does not grow. Its subsystem, the economy, must eventually stop growing, but can continue to develop. The term "sustainable development" therefore makes sense for the economy, but only if it is understood as "development without growth"—i.e., qualitative improvement of a physical economic base that is maintained in a steady state by a throughput of matter-energy that is within the regenerative and assimilative capacities of the ecosystem. Currently the term "sustainable development" is used as a synonym for the oxymoronic "sustainable growth." It must be saved from this perdition.
Politically it is very difficult to admit that growth, with its almost religious connotations of ultimate goodness, must be limited. But it is precisely the nonsustainability of growth that gives urgency to the concept of sustainable development. The earth will not tolerate the doubling of even one grain of wheat 64 times, yet in the past two centuries we have developed a culture dependent on exponential growth for its economic stability (Hubbert, 1976). Sustainable development is a cultural adaptation made by society as it becomes aware of the emerging necessity of nongrowth. Even "green growth" is not sustainable. There is a limit to the population of trees the earth can support, just as there is a limit to the populations of humans and of automobiles. To delude ourselves into believing that growth is still possible and desirable if only we label it "sustainable" or color it "green" will just delay the inevitable transition and make it more painful.
Limits to Growth?
If the economy cannot grow forever then by how much can it grow? Can it grow by enough to give everyone in the world today a standard of per capita resource use equal to that of the average American? That would turn out to be a factor of seven,*l a figure that is neatly bracketed by the Brundtland Commission's call (Brundtland et al., 1987) for the expansion of the world economy by a factor of five to ten. The problem is that even expansion by a factor of four is impossible if Vitousek et al. (1986, pp. 368-373) are correct in their calculation that the human economy currently preempts one-fourth of the global net primary product of photosynthesis (NPP). We cannot go beyond 100 percent, and it is unlikely that we will increase NPP since the historical tendency up to now is for economic growth to reduce global photosynthesis. Since land-based ecosystems are the more relevant, and we preempt 40 percent of land-based NPP, even the factor of four is an overestimate. Also, reaching 100 percent is unrealistic since we are incapable of bringing under direct human management all the species that make up the ecosystems upon which we depend. Furthermore it is ridiculous to urge the preservation of biodiversity without being willing to halt the economic growth that requires human takeover of places in the sun occupied by other species.
If growth up to the factor of five to ten recommended by the Brundtland Commission is impossible, then what about just sustaining the present scale -- i.e., zero net growth? Every day we read about stress-induced feedbacks from the ecosystem to the economy, such as greenhouse buildup, ozone layer depletion, acid rain, etc., which constitute evidence that even the present scale is unsustainable. How then can people keep on talking about "sustainable growth" when: (a) the present scale of the economy shows clear signs of unsustainability, (b) multiplying that scale by a factor of five to ten as recommended by the Brundtland Commission would move us from unsustainability to imminent collapse, and (c) the concept itself is logically self-contradictory in a finite, nongrowing ecosystem? Yet sustainable growth is the buzz word of our time. Occasionally it becomes truly ludicrous, as when writers gravely speak of "sustainable growth in the rate of increase of economic activity." Not only must we grow forever, we must accelerate forever! This is hollow political verbiage, totally disconnected from logical and physical first principles.
Alleviating Poverty, Not Angelizing GNP
The important question is the one that the Brundtland Commission leads up to, but does not really face: How far can we alleviate poverty by development without growth? I suspect that the answer will be a significant amount, but less than half. One reason for this belief is that if the five- to tenfold expansion is really going to be for the sake of the poor, then it will have to consist of things needed by the poor—food, clothing, shelter—not information services. Basic goods have an irreducible physical dimension and their expansion will require growth rather than development, although development via improved efficiency will help. In other words, the reduction in resource content per dollar of GNP observed in some rich countries in recent years cannot be heralded as severing the link between economic expansion and the environment, as some have claimed. Angelized GNP will not feed the poor. Sustainable development must be development without growth—but with population control and wealth redistribution—if it is to be a serious attack on poverty.
In the minds of many people, growth has become synonymous with increase in wealth. They say that we must have growth to be rich enough to afford the cost of cleaning up and curing poverty. That all problems are easier to solve if we are richer is not in dispute. What is at issue is whether growth at the present margin really makes us richer. There is evidence that in the US it now makes us poorer by increasing costs faster than it increases benefits (Daly and Cobb, 1989, appendix). In other words we appear to have grown beyond the optimal scale.
Defining the Optimal Scale
The concept of an optimal scale of the aggregate economy relative to the ecosystem is totally absent from current macroeconomic theory. The aggregate economy is assumed to grow forever. Microeconomics, which is almost entirely devoted to establishing the optimal scale of each microlevel activity by equating costs and benefits at the margin, has neglected to inquire if there is not also an optimal scale for the aggregate of all micro activities. A given scale (the product of population times per capita resource use) constitutes a given throughput of resources and thus a given load on the environment, and can consist of many people each consuming little, or fewer people each consuming correspondingly more.
An economy in sustainable development adapts and improves in knowledge, organization, technical efficiency, and wisdom; and it does this without assimilating or accreting, beyond some point, an ever greater percentage of the matter-energy of the ecosystem into itself, but rather stops at a scale at which the remaining ecosystem (the environment) can continue to function and renew itself year after year. The nongrowing economy is not static—it is being continually maintained and renewed as environment.
What policies are implied by the goal of sustainable development, as here defined? Both optimists and pessimists should be able to agree on the following policy for the US (sustainable development should begin with the industrialized countries). Strive to hold throughput constant at present levels (or reduced truly sustainable levels) by taxing resource extraction, especially energy, very heavily. Seek to raise most public revenue from such resource severance taxes, and compensate (achieve revenue neutrality) by reducing the income tax, especially on the lower end of the income distribution, perhaps even financing a negative income tax at the very low end.
Optimists who believe that resource efficiency can increase by a factor of ten should welcome this policy, which raises resource prices considerably and would give powerful incentive to just those technological advances in which they have so much faith. Pessimists who lack that technological faith will nevertheless be happy to see restrictions placed on the size of the already unsustainable throughput. The pessimists are protected against their worst fears; the optimists are encouraged to pursue their fondest dreams. If the pessimists are proven wrong and the enormous increase in efficiency actually happens, then they cannot complain. They got what they most wanted, plus an unexpected bonus. The optimists, for their part, can hardly object to a policy that not only allows but gives a strong incentive to the very technical progress on which their optimism is based. If they are proved wrong at least they should be glad that the throughput-induced rate of environmental destruction has been slowed. Also severance taxes are harder to avoid than income taxes and do not reduce incentives to work.
At the project level there are some additional policy guidelines for sustainable development. Renewable resources should be exploited in a manner such that:
1. Harvesting rates do not exceed regeneration rates.
2. Waste emissions do not exceed the renewable assimilative capacity of the local environment.
Balancing Nonrenewable and Renewable Resources
Nonrenewable resources should be depleted at a rate equal to the rate of creation of renewable substitutes. Projects based on exploitation of nonrenewable resources should be paired with projects that develop renewable substitutes. The net rents from the nonrenewable extraction should be separated into an income component and a capital liquidation component. The capital component would be invested each year in building up a renewable substitute. The separation is made such that by the time the nonrenewable is exhausted, the substitute renewable asset will have been built up by investment and natural growth to the point where its sustainable yield is equal to the income component. The income component will have thereby become perpetual, thus justifying the name "income," which is by definition the maximum available for consumption while maintaining capital intact. It has been shown (El Serafy, 1989, pp. 10-18) how this division of rents into capital and income depends upon: (1) the discount rate (rate of growth of the renewable substitute); and (2) the life expectancy of the nonrenewable resource (reserves divided by annual depletion). The faster the biological growth of the renewable substitute and the longer the life expectancy of the nonrenewable, the greater will be the income component and the less the capital set-aside. "Substitute" here should be interpreted broadly to include any systemic adaptation that allows the economy to adjust the depletion of the nonrenewable resource in a way that maintains future income at a given level (e.g., recycling in the case of minerals). Rates of return for the paired projects should be calculated on the basis of their income component only.
However, before these operational steps toward sustainable development can get a fair hearing, we must first take the conceptual and political step of abandoning the thought-stopping slogan of "sustainable growth."
*1. Consider the following back-of-the-envelope calculation, based on the crude estimate that the US currently uses 1/3 of annual world resource flows (derived from National Commission on Materials Policy, 1973). Let R be current world resource consumption. Then R13 is current US resource consumption, and R/3 divided by 250 million is present per capita US resource consumption. Current world per capita resource consumption would be R divided by 5.3 billion. For future world per capita resource consumption to equal present US per capita consumption, assuming constant population, R must increase by some multiple, call it M. Then M times R divided by 5.3 billion must equal R/3 divided by 250 million. Solving for M gives 7. World resource flows must increase sevenfold if all people are to consume resources at the present US average. But even the sevenfold increase is a gross underestimate of the increase in environmental impact, for two reasons. First, because the calculation is in terms of current flows only with no allowance for the increase in accumulated stocks of capital goods necessary to process and transform the greater flow of resources into final products. Some notion of the magnitude of the extra stocks needed comes from Harrison Brown's estimate that the "standing crop" of industrial metals already embodied in the existing stock of artifacts in the ten richest nations would require more than 60 years' production of these metals at 1970 rates. Second, because the sevenfold increase of net usable minerals and energy will require a much greater increase in gross resource flows, since we must mine ever less accessible deposits and lower grade ores. It is the gross flow that provokes environmental impact.
Brundtland, G. H., et al. 1987. Our Common Future: Report of the World Commission on Environment and Development. Oxford: Oxford University Press.
Daly, H. E., and J. B. Cobb, Jr. 1989. For the Common Good: Redirecting the Economy toward Community, the Environment and a Sustainable Future. Boston: Beacon Press.
El Serafy, S. 1989. "The Proper Calculation of Income from Depletable Natural Resources." In Y. J. Ahmad, S. El Serafy, and E. Lutz, eds., Environmental Accounting for Sustainable Development, a UNEP-World Bank Symposium. Washington, D.C.: The World Bank.
Hubbert, M. King. 1976. "Exponential Growth as a Transient Phenomenon in Human History." In Margaret A. Storm, ed., Societal Issues: Scientific Viewpoints. New York: American Institute of Physics. (Reprinted in this volume.)
National Commission on Materials Policy. 1973. Material Needs and the Environment Today and Tomorrow. Washington, D.C.: US Government Printing Office
Vitousek, Peter M., Paul R. Ehrlich, Anne H. Ehrlich, and Pamela A. Matson. 1986. "Human Appropriation of the Products of Photosynthesis." BioScience 34. (6 May).