Hello Dragonfly, and welcome. Thanks for posting this. >Found this in a newsgroup....could someone verify it's accuracy?
Which newsgroup did you find it in? The link is to the M. King Hubbert Center for Petroleum Supply Studies. "Mission: Assemble, study, and disseminate global petroleum supply data". One of the most controversial issues relating to ethanol is the question of what environmentalists call the "net energy" of ethanol production. Simply put, is more energy used to grow and process the raw material into ethanol than is contained in the ethanol itself? A US Department of Agriculture study concludes that ethanol contains 34% more energy than is used to grow and harvest the corn and distill it into ethanol. "Estimating the Net Energy Balance of Corn Ethanol", by Hosein Shapouri et al., US Department of Agriculture, Economic Research Service, Office of Energy and New Uses, Agricultural Economic Report No. 721, July 1995 -- "Studies conducted since the late 1970s have estimated the net energy value of corn ethanol. However, variations in data and assumptions used among the studies have resulted in a wide range of estimates. This study identifies the factors causing this wide variation and develops a more consistent estimate... We show that corn ethanol is energy efficient as indicated by an energy ratio of 1.24." http://www.ethanol-gec.org/corn_eth.htm In "How Much Energy Does It Take to Make a Gallon of Ethanol?", David Lorenz and David Morris of the Institute for Local-Self Reliance (ILSR) state: "Using the best farming and production methods, the amount of energy contained in a gallon of ethanol is more than twice the energy used to grow the corn and convert it to ethanol." A 1992 ILSR study, based on actual energy consumption data from farmers and ethanol plant operators, found that the production of ethanol from corn is a positive net energy generator. In this updated paper the numbers look even more attractive: more energy is contained in the ethanol and the other by-products of corn processing than is used to grow the corn and convert it into ethanol and by-products. http://www.carbohydrateeconomy.org/ceic/library/admin/uploadedfiles/Ho w_Much_Energy_Does_it_Take_to_Make_a_Gallon_.html "Ethanol production is extremely energy efficient, with a positive energy balance of 125%, compared to 85% for gasoline. Ethanol production is by far the most efficient method of producing liquid transportation fuels. According to USDA, each BTU (British Thermal Unit, an energy measure) used to produce a BTU of gasoline could be used to produce 8 BTUs of ethanol." -- American Coalition for Ethanol (ACE) http://www.ethanol.org/ethanol_info.html In fact it's a very theoretical question. A "standard" farming procedure is a myth, and even if it wasn't, what would that have to do with a homesteader with a good supply of waste wood to burn and no better way of using it, and a large supply of past-their-use-by cakes from a bread factory that he's rescuing from the waste stream? (An actual case.) The cakes could go to a pig farm instead, but they don't. There are many such niches -- spoiled fruit from farms that ought to have pigs but don't, and so on and on. Such factors never get calculated. Pimental's report is also very US-specific. Dick Carlstein has painted a quite different picture of ethanol production in Brazil, for instance. (Search the list archives for "Brazil".) Once you start looking at the local level and at integrated approaches to crop production and wastes, and include energy production and use, a very different picture emerges that leaves these broad energy in/energy out generalisations without much meaning. There's yet another way of looking at it. This is from Offgrid-Online, April 5, 2000. http://www.offgridknowhow.com/ "Will we get out more energy than we put in? Does it matter? Generally a scheme that did not create more energy than it consumed would be useless, but in this case we might have a different view. Since we are after a portable fuel, we might be willing to spend more energy to get it, so long as we used a non-portable fuel to do so. For example, suppose we use wood-fired heat to make alcohol. Wood is a poor fuel as far as portability in general is concerned and is nearly useless for internal combustion engines. So what if we have to spend 2 BTUs of wood heat for each BTU of alcohol fuel produced? That might still be a good deal if we had lots of wood and gasoline was (that is, continues to be) highly priced." http://www.homesteadtechnology.com/newsletters/20000405.txt The Sierra Club in the US has a different objection to ethanol. They see the whole issue as clouded by the high levels of nitrogen fertilisers used to grow the maize, and the terrific eco-damage the N-runoff causes. But that's an objection to US factory farming, not to ethanol. In a more rational system there's no need for nitrogen fertilisers, and no loss of yield through not using them. None of this considers the fact that ethanol is a much cleaner fuel than gasoline, reducing air-pollution, nor that it is a renewable fuel made from plants -- unlike fossil-fuels, manufacturing it and burning it does not increase the greenhouse effect. It also has an important role in biodiesel production: ethyl esters biodiesel is cleaner and more rational than methyl esters biodiesel made with methanol, which, unlike ethanol, is toxic, derived from fossil fuels, and you can't make it yourself. It also substitutes for MTBE oxygenate. MTBE is filthy stuff. See "Is ethanol energy-efficient?" http://journeytoforever.org/ethanol_energy.html Almost every paragraph of Pimental's report is debunkable. Turtuous reasoning indeed to use the environmental damage caused by the fossil fuel use of US industrial farming to discredit ethanol, when what's the alternative to ethanol other than fossil fuels? The section on "Food Versus Fuel Issues" is nonsense. >Present food shortages throughout the world call attention to the >importance >of continuing U.S. exports of corn and other grains for human food to >reduce >malnutrition and starvation. Increased corn exports increase the market >for >corn, improve the U.S. balance of payments, and most importantly help >feed >people who need additional food for their survival. Present U.S. grain >exports total about $40 billion per year (USBC, 1996). Clearly using >corn >for food is beneficial for many reasons. > >Expanding ethanol production could >entail >diverting essential cropland from producing corn needed to sustain human >life to producing corn for ethanol factories. There IS NO FOOD SHORTAGE. Increased US corn exports DO NOT help feed people who need additional food for their survival, they often have quite the opposite effect. I'm very suspicious of people who still make these spurious claims. About a billion people now don't have enough food to meet basic daily needs. But that's NOT because there's not enough food. There's more food per capita now than there's ever been before. And it's a myth that most of it's grown in the rich countries. The US, for instance, is the world's biggest ever food IMPORTER. People starve because they're victims of an inequitable economic system, not because they're victims of scarcity and overpopulation. The links below are good resources on this issue, they've done their homework and they've got their numbers right. The Myth of Scarcity http://www.foodfirst.org/pubs/backgrdrs/1998/w98v5n1.html 12 Myths About Hunger http://www.foodfirst.org/pubs/backgrdrs/1998/s98v5n3.html From "The Myth of Scarcity" "The world today produces enough grain alone to provide every human being on the planet with 3,500 calories a day. That's enough to make most people fat! And this estimate does not even count many other commonly eaten foods - vegetables, beans, nuts, root crops, fruits, grass-fed meats, and fish. In fact, if all foods are considered together, enough is available to provide at least 4.3 pounds of food per person a day. That includes two and half pounds of grain, beans and nuts, about a pound of fruits and vegetables, and nearly another pound of meat, milk and eggs. "Abundance, not scarcity, best describes the supply of food in the world today. Increases in food production during the past 35 years have outstripped the world's unprecedented population growth by about 16 percent. Indeed, mountains of unsold grain on world markets have pushed prices strongly downward over the past three and a half decades. Grain prices rose briefly during the early 1990s, as bad weather coincided with policies geared toward reducing overproduction, but still remained well below the highs observed in the early sixties and mid-seventies. All well and good for the global picture, you might be thinking, but doesn't such a broad stroke tell us little? Aren't most of the world's hungry living in countries with food shortages - countries in Latin America, in Asia, and especially in Africa? "Hunger in the face of ample food is all the more shocking in the Third World. According to the Food and Agriculture Organization (FAO) of the United Nations, gains in food production since 1950 have kept ahead of population growth in every region except Africa. The American Association for the Advancement of Science (AAAS) found in a 1997 study that 78% of all malnourished children under five in the developing world live in countries with food surpluses. "Thus, even most "hungry countries" have enough food for all their people right now. This finding turns out to be true using official statistics even though experts warn us that newly modernizing societies invariably underestimate farm production - just as a century ago at least a third of the U.S. wheat crop went uncounted. Moreover, many nations can't realize their full food production potential because of the gross inefficiencies caused by inequitable ownership of resources. "Finally, many of the countries in which hunger is rampant export much more in agricultural goods than they import. Northern countries are the main food importers, their purchases representing 71.2 percent of the total value of food items imported in the world in 1992. Imports by the 30 lowest-income countries, on the other hand, accounted for only 5.2 percent of all international commerce in food and farm commodities." [more] Anyway, most US corn exports are for livestock feed, not human food. With ethanol, for instance, the distillers dried grains by-product is more nutritious than the original unprocessed grain (because of the yeast), so in a sense, on a nutritional scale, you get the ethanol for nothing, or less than nothing. This is what causes hunger, not lack of US corn exports: The annual UN Human Development Report says the effects of globalisation and increasing economic integration have led to the rich getting richer and the poor getting poorer in nearly every way. Three billion people now live on less than $2.00 a day. One billion people live on less than $1.00 a day. (World Bank) UN statistics provide evidence of the widening gap between rich and poor: In nine years, the income ratio between the top 20% and the bottom 20% has increased from 60:1 to 74:1. Eighty countries have less revenue than they did a decade ago. The assets of the 200 richest people exceed the combined income of 41% of the world's total population. Economic growth is projected as the road to overcome global poverty. With economic growth of $100 the rich 20% of the world population pocket $83 and the poorest 20% get $1.40. Global economic growth is therefore a highly inefficient way to help the global poor. Wealth extraction causes poverty, and poverty causes hunger. To sum up, you can make these so-called "life-cycle" studies mean whatever you want,they don't have any real meaning. I'm uncomfortable supporting ethanol but finding that it puts me on the same side as the likes of Archer Daniels Midlands, which is an evil corporation. This might be quite an effective attack on ADM et al, but it's a pity to make ethanol the scapegoat. It's a real pity ethanol is being put on the wrong side of the environmental divide because of US industrial farming issues. The question I learnt always to ask in reporting Third World development issues is, who benefits, and at whose expense? As you dug further, the initial answers would neatly change sides. The main beneficiaries of this article would seem to be Big Oil. I'm surprised at David Pimental, I'd thought better of him. I'll check it out. Best wishes Keith Addison Journey to Forever Handmade Projects Tokyo http://journeytoforever.org/ >ENERGY AND DOLLAR COSTS OF ETHANOL PRODUCTION WITH CORN >by David Pimentel > >Introduction > >Ethanol does not provide energy security for the future. It is not a >renewable energy source, is costly in terms of production and subsidies, >and >its production causes serious environmental degradation (ERAB, 1980, >1981; >Dorving, 1988; GAO, 1990; Pimentel, 1991; Sparks Commodities, 1990; >Giampietro et al., 1997). > >Clearly, conclusions drawn about the benefits and costs of ethanol >production will be incomplete or misleading if only a part of the total >system is assessed (Giampietro et al., 1997). The objective of this >analysis >is to update and assess all the recognized factors that operate in the >entire ethanol production system. These include direct and indirect >costs in >terms of fossil energy and dollars expended in producing the corn >feedstock >as well as in the fermentation and distillation processes. > >Energy Balance > >The conversion of corn and some other food/feed crops into ethanol by >fermentation is a well known and established technology. In a large and >efficient plant with economies of scale, the yield from a bushel of corn >is >about 2.5 gallons of ethanol. > >The production of corn in the United States requires significant energy >and >dollar inputs. Indeed, growing corn is a major energy and dollar cost of > >producing ethanol (Pimentel, 1991; Giampietro et al., 1997). For >example, to >produce an average of 120 bushels of corn per acre using conventional >production technology requires more than 140 gallons of gasoline >equivalents >and costs about $280 (Pimentel, 1992). The major energy inputs in U.S. >corn >production are oil, natural gas, and/or other high grade fuels. >Fertilizer >production and fuels for mechanization account for about two-thirds of >these >energy inputs for corn production (Pimentel, 1991). > >HC#98/2-1-1 > >April 1998 > >Once corn is harvested, three additional energy expenditures contribute >to >the total costs in the conversion process. These include energy to >transport >the corn material to the ethanol plant, energy expended relating to >capital >equipment requirements for the plant, and energy expended in the plant >operations for the fermentation and distillation processes. > >The average costs in terms of energy and dollars for a large modern >ethanol >plant (60-70 million gallon/yr) are listed in Table 1. The largest >energy >inputs are for corn production and fuel energy expended in the >fermentation/distillation process. The total energy input to produce one > >gallon of ethanol is 129,600 BTU. However, one gallon of ethanol has an >energy value of only 76,000 BTU. Thus, a net energy loss of 53,600 BTU >occurs for each gallon of ethanol produced. Put another way, about 71% >more >energy is required to produce a gallon of ethanol than the energy that >is >contained in a gallon of ethanol (Table 1). > >About 63% of the cost of producing ethanol ($2.52 per gallon) in a large > >plant is for the corn feedstock itself (Table 1). This cost is offset, >in >part, by the by-product (dried-distillers grain) which is produced and >can >be fed to livestock. However, most of the cost contributions from >by-products are negated by the costs of environmental pollution that >result >from the production processes. These are estimated to be $0.36 per >gallon of >ethanol produced (Pimentel, 1991; Giampietro et al., 1997). This shows >that >the environmental system in which corn is being produced is rapidly >being >degraded. Furthermore, it substantiates the finding that the U.S. corn >production system is not sustainable unless major changes are made in >the >cultivation of this important food/feed crop. Hence, corn cannot be >considered a renewable resource. > > >Energy Inputs in Ethanol Production > >About 1 billion gallons of ethanol are currently produced in the United >States each year (Peterson et al., 1995). This quantity of ethanol >provides >less than 1% of the fuel utilized by U.S. automobiles (USBC, 1996). > >The amount of cropland that is required to grow sufficient corn to fuel >each >automobile is a vital factor when considering the advisability of >producing >ethanol for automobiles. To clarify this problem, the amount of cropland > >needed to fuel one automobile with ethanol was calculated. An average >U.S. >car travels about 10,000 miles per year and uses about 520 gallons of >gasoline. Although 120 bushels per acre of corn yield 300 gallons of >ethanol, its energy equivalent to gasoline is only 190 gallons because >ethanol has a much lower BTU content than gasoline (76,000 BTU versus >120,000 BTU for gasoline per gallon). As shown above, there is a >significant >net energy loss in producing ethanol. However, even assuming zero or no >energy charge for the fermentation and distillation processes and >charging >only for the energy required to produce corn (Table 1), the net ethanol >energy yield from one acre of corn is only 50 gallons (190 gallons minus >140 >gallons). Therefore, to provide the equivalent of 520 gallons of >gasoline >per car, about 10.4 acres of corn must be grown to fuel one car with >ethanol >for one year. > >Land Used in Ethanol Production > >To fuel one car with ethanol for one year means that nearly 7-times more > >cropland would be required to fuel one car than is needed to feed one >American (USDA, 1996). > >Assuming a net production of 50 gallons of fuel per acre of corn, and >assuming that all cars in the United States were fueled with ethanol, a >total of approximately 2 billion acres of cropland would be required to >provide the corn feedstock. This amount of acreage is more than 5-times >all >the cropland that is actually and potentially available for all crops in >the >future in the United States. > >A major problem associated with corn production is soil erosion. In U.S. > >corn production, soil erodes about 20-times faster than soil can be >reformed >(Pimentel et al., 1995). As soil quality diminishes, production moves to > >marginal land which increases the susceptibility of the corn crop to >climate >fluctuations, particularly droughts. For example, during 1988 a drought >reduced the corn crop by about 30% (USDA, 1989). These severe >fluctuations >in corn production occur periodically every 4 to 5 years. Additionally, >in >irrigated corn acreage, groundwater is being mined 25% faster than the >recharge rate (USWRC, 1979). > >These land and water problems already demonstrate that the U.S. corn >production system uses large quantities of basic resources. Unless major > >changes can be made in the cultivation of this major food/feed crop it >cannot be considered a renewable resource that can be relied on to >provide >energy security for the United States. > >Environmental Impacts > >Ethanol production, in both the growing of the corn and in the >fermentation >/ distillation process, adversely affects the quality of the environment >in >diverse ways. All these environmental problems cost the consumer and the > >nation, and most importantly, diminish the long term sustainability of >U.S. >agriculture and environmental integrity. > >As mentioned, corn is one of the major row crops now responsible for >serious >soil erosion in the United States. Estimates are that about 9 tons of >soil >per acre are eroded per year by rain and wind in corn production areas >(Lal >and Pierce, 1991). Note, this rate of soil loss is about 20-times faster > >than soil reformation in agriculture (Lal and Stewart, 1990; Pimentel et > >al., 1995). To replace soil nutrients that are lost as soil erodes, an >estimated $20 billion per year is required (Troeh et al., 1991). > >In addition to being the largest user of fertilizers among all U.S. >crops, >corn production also is the largest user of insecticides and herbicides >(Pimentel, 1997). Unfortunately, substantial amounts of these chemicals >are >washed and/or drift from the target areas to contaminate adjoining >terrestrial and aquatic ecosystems. Monitoring for fertilizer and >pesticide >pollution in U.S. well water and groundwater is estimated to cost the >nation >$2 billion per year-- if an adequate job of monitoring were done-- of >which >$1.2 billion would be expended just for pesticides (Nielsen and Lee, >1987). >Other environmental damages caused by pesticides are estimated to cost >the >nation more than $8 billion per year (Pimentel, 1997). Although these >may be >necessary expenditures for food production, their impact must be >considered >when evaluating the environmental effects of producing ethanol fuels. > >Furthermore, major pollution problems also are associated with the >production of ethanol in the conversion plant. For each gallon of corn >ethanol produced, about 160 gallons of waste water are produced. This >waste >water has a biological oxygen demand (BOD) of 18,000-37,000 mg/liter >depending on the type of plant. If the cost of processing this sewage is > >included in the pollution cost of $0.36 per gallon, it would add another > >$0.06 per gallon and the total pollution costs per gallon would be >$0.42. > >Ethanol produces less carbon monoxide than gasoline, but it produces >just as >much nitrous oxides as gasoline. In addition, ethanol adds aldehydes and > >alcohol to the atmosphere, all of which are carcinogenic. When all air >pollutants associated with the entire ethanol system are measured, >ethanol >production is found to contribute to major air pollution problems. The >129,600 BTU of fossil fuel including coal, oil, and natural gas, which >are >expended in corn production and subsequently burned in the ethanol plant > >release significant amounts of pollutants into the atmosphere. Also, the > >carbon dioxide emissions released from burning these fossil fuels >contribute >to the global warming problem (Parry, 1990). This becomes an extremely >serious concern when coal is used as the fuel for the >fermentation/distillation processes. Thus, overall environmental >pollution >and its costs associated with ethanol production will increase if >ethanol >production is expanded. > >Food Versus Fuel Issues > >Burning a human-food resource (corn) for fuel, as happens when ethanol >is >produced, raises important ethical and moral issues. Today the number of > >malnourished people in the world stands at more than 2 billion, about >one-third of the world's population (WHO, 1995). This is the largest >number >of malnourished people in human history, and the number is growing. >Coupled >with this existing problem is the escalating rate of growth in the human > >population. More than a quarter of a million people are added each day >to >the world population, and each of these human beings requires adequate >food. >World data confirm that per capita food supplies have been declining for >the >past 12 years (FAO, 1996; Pimentel et al., 1997). > >Present food shortages throughout the world call attention to the >importance >of continuing U.S. exports of corn and other grains for human food to >reduce >malnutrition and starvation. Increased corn exports increase the market >for >corn, improve the U.S. balance of payments, and most importantly help >feed >people who need additional food for their survival. Present U.S. grain >exports total about $40 billion per year (USBC, 1996). Clearly using >corn >for food is beneficial for many reasons. > >Agricultural land supplies more than 99% of all world food while the >oceans >supply less than 1% (FAO, 1991). Expanding ethanol production could >entail >diverting essential cropland from producing corn needed to sustain human > >life to producing corn for ethanol factories. This will create serious >practical as well as ethical problems. Already worldwide (including the >United States) per capita supplies of cropland and fresh water are >declining, while soil erosion, deforestation, and food losses to pests >are >increasing. All these factors are contributing to food shortages >throughout >the world. Therefore, the practical aspects as well as the moral and >ethical >issues must be seriously considered before steps are taken to produce >and >convert more corn into ethanol. Clearly the ethical issue of burning >corn >will become more intense as human food supplies must be augmented to >meet >the basic needs of the rapidly growing world population. > >Subsidies > >A recent report by the U.S. General Accounting Office which analyzed tax > >costs and federal farm program expenditures associated with projected >increased ethanol production has added to our understanding of the >complexities of ethanol production. The 1990 report concluded that: (1) >increasing ethanol production would greatly increase tax-subsidy >expenditures; (2) no projections could be made concerning any net >federal >budget savings from increasing ethanol production; and (3) an estimate >of >any overall federal budget impact was precluded because of the >uncertainties >about production economics for both ethanol and gasoline (GAO, 1990). In > >addition the report indicated that it was impossible to calculate how >much >higher the subsidies might have to be increased to encourage a measured >expansion of ethanol production, if the expansion were needed at all. > >Conclusion > >Ethanol production is wasteful of fossil energy resources and does not >increase energy security. This is because considerably more energy, much >of >it high-grade fossil fuels, is required to produce ethanol than is >available >in the ethanol output. Specifically, about 71% more energy is used to >produce a gallon of ethanol than the energy contained in a gallon of >ethanol. > >Furthermore, ethanol production from corn cannot be considered renewable > >energy. Its production uses more nonrenewable fossil energy resources >both >in the production of the corn and in the fermentation/distillation >processes >than is produced as ethanol energy. > >Unfortunately ethanol produced from corn and other food crops is an >unreliable source of energy because of uncontrollable climatic >fluctuations, >particularly droughts which frequently reduce crop yields. The expected >priority for corn and other food crops would be for food and feed. > >Increasing ethanol production will increase degradation of vital >agricultural land and water resources and will seriously contribute to >the >pollution of the environment. In U.S. corn production, soil erodes some >20-times faster than soil is reformed. > >If there were no tax payer money paid to subsidize the ethanol >production >industry, there would be no ethanol produced as a fuel for automobiles. > >Increasing the diversion of human food resources to support the costly >and >inefficient production of ethanol fuel raises major ethical questions. >This >is especially true when there are more than two billion humans who are >malnourished in the world. > >TABLE 1 >Energy and dollar inputs for a gallon of ethanol >(Pimentel, 1991, 1992; USBC, 1996; USDA, 1996; Giampietro et al., 1997). > >Inputs BTU Dollars > >Corn Production 55,300 $1.60 >Fermentation/Distillation 74,300 $0.92 >TOTAL 129,600 $2.52 > >References > >Dorving, F. 1988. Farming for Fuel. New York: Praeger. >ERAB. 1980. Gasohol. Washington, DC: Energy Research Advisory Board, >U.S. >Department of Energy. >ERAB. 1981. Biomass Energy. Washington, DC: Energy Research Advisory >Board, >U.S. Department of Energy. >FAO. 1991. Food Balance Sheets. Rome: Food and Agriculture Organization >of >the United Nations. >FAO. 1996. Quarterly Bulletin of Statistics. FAO Quarterly Bulletin of >Statistics 9: 1-121. >GAO. 1990. Alcohol Fuels. Washington, DC: U.S. General Accounting >Office, >GAO/RCED-90-156. >Giampietro, M., S. Ulgiati, and D. Pimentel. 1997. Feasibility of >large-scale biofuel production. BioScience 47 (9): 587-600. >Lal, R. and B.A. Stewart. 1990. Soil Degradation. New York: >Springer-Verlag. >Lal, R. and F.J. Pierce. 1991. Soil Management for Sustainability. >Ankeny, >Iowa: Soil and Water Conservation Soc. in Coop. with World Assoc. of >Soil >and Water Conservation and Soil Sci. Soc. of Amer. >Nielson, E.G. and L.K. Lee. 1987. The Magnitude and Costs of Groundwater > >Contamination from Agricultural Chemicals. U.S. Dept. of Agr., Econ. >Res. >Ser., Nat., Res. Econ. Div., Staff. Re., AGES 870318. >Parry, M. 1990. Climate Change and World Agriculture. London: Earthscan >Publications, Ltd. >Peterson, C.L., M.E. Casada, L.M. Safley, and J.D. Broder. 1995. >Potential >production of agriculturally produced fuels. Applied Engineering in >Agriculture 11(6): 767-772. >Pimentel, D. 1991. Ethanol fuels: Energy security, economics, and the >environment. J. Agr. Environ. Ethics 4: 1-13. >Pimentel, D. 1992. Energy inputs in production agriculture. In Energy in > >World Agriculture, ed. R.C. Fluck. pp. 13-29. Amsterdam: Elsevier. >Pimentel, D. 1997. Techniques for Reducing Pesticides: Environmental and > >Economic Benefits. Chichester, UK: John Wiley & Sons. >Pimentel, D., C. Harvey, P. Resosudarmo, K. Sinclair, D. Kurz, M. >McNair, S. >Crist, L. Sphpritz, L. Fitton, R. Saffouri, and R. Blair. 1995. >Environmental and economic costs of soil erosion and conservation >benefits. >Science 267: 1117-1123. >Pimentel, D., X. Huang, A. Cardova, and M. Pimentel. 1997. Impact of >population growth on food supplies and environment. Population and >Environment 19(1): 9-14. >Sparks Commodities. 1990. Impacts of the Richardson Amendment to H.R. >3030 >on U.S. Agricultural Sector. McLean, VA: Sparks Commodities, Inc., >Washington Division. >Troeh, F.R, J.A Hobbs, and R.L. Donahue. 1991. Soil and Water >Conservation. >2nd ed., Englewood Cliffs, NJ: Prentice Hall. >USBC. 1996. Statistical Abstract of the United States. 201st ed. >Washington, >DC: U.S. Bureau of the Census, U.S. Government Printing Office. >USDA. 1989. Agricultural Statistics. Washington, DC: USDA. >USDA. 1996. Agricultural Statistics. Washington, DC: USDA. >USWRC. 1979. The Nation's Water Resources. 1975-2000. Vol. 1-4. Second >National Water Assessment, Washington, DC: U.S. Water Resources Council. > >WHO. 1995. Bridging the Gaps. Geneva: World Health Organization. > > >The Author: David Pimentel > >David Pimentel is a professor of ecology and agricultural science at >Cornell >University, Ithaca, NY 14853-0901. His Ph.D. is from Cornell University. >His >research spans the fields of energy, land and water conservation, and >natural resource management. Pimentel has published more than 475 >scientific >papers and 20 books and has served on many national and government >committees including the National Academy of Sciences; President's >Science >Advisory Council; U.S. Department of Agriculture; U.S. Department of >Energy; >U.S. Department of Health, Education and Welfare; Office of Technology >Assessment of the U.S. Congress; and the U.S. State Department. > >David Pimentel >[EMAIL PROTECTED] >College of Agriculture and Life Sciences > >Cornell University >5126 Comstock Hall >Ithaca, New York 14853-0901 >607-255-2212 >607-255-0939 (fax) > >April 1998 > >http://hubbert.mines.edu/news/v98n2/mkh-new7.html ------------------------ Yahoo! Groups Sponsor ---------------------~-~> eGroups is now Yahoo! 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