Page 15 - Academic Press Encyclopedia of Physical Science and Technology 3rd BioTechnology

P1: FJU Revised Pages
Encyclopedia of Physical Science and Technology EN002C-60 May 17, 2001 20:23

Biomass Utilization, Limits of 171

as to how much biomass can be harvested as an energy Sciences, Cornell University; Joel Snow, Iowa State University; and Paul
source without further causing the extinction of more Weisz, Pennsylvania State University.
plants, animals, and microbes because of biomass re-
sources on which biodiversity depends. Agriculture and
managed forests occupy approximately 70% of the total SEE ALSO THE FOLLOWING ARTICLES
land area and use about 70% of the total water consumed
by society, and this further limits natural biodiversity. BIOREACTORS • ENERGY FLOWS IN ECOLOGY AND IN THE
However, opportunities do exist to combine agriculture ECONOMY • GREENHOUSE EFFECT AND CLIMATE DATA •
and forest production. If this is to be done several changes POLLUTION,AIR • POLLUTION CONTROL • RENEWABLE
would have to be made in many technologies now used in ENERGY FROM BIOMASS • WASTE-TO-ENERGY SYSTEMS
agriculture and forestry. These technologies include con- • WATER POLLUTION
serving soil, water, and nutrient resources. Of particular
importance is keeping the land covered with vegetation
BIBLIOGRAPHY
and maintaining high levels of organic matter in the soil.
Although biomass resources have a lower sulfur con-
Ellington, R. T., Meo, M., and El-Sayed, D. A. (1993). “The net green-
tent than oil and coal, biomass energy conversion and use
house warming forcing of methanol produced from biomass,” Biomass
has associated environmental and public health problems.
Bioenergy 4(6): 405–418.
For example, the chemical emissions from wood-burning Ferguson, A. R. B. (2000). “Biomass and Energy,” The Optimum Popu-
for cooking and heating produce serious chemical pol- lation Trust, Manchester, U.K.
lutants, including some carcinogens and other toxicants. Pimentel, D. (1991). “Ethanol fuels: Energy security, economics, and the
environment,” J. Agr. Environ. Ethics 4, 1–13.
In addition, on the basis of a million kilocalorie output,
Pimentel, D., Doughty, R., Carothers, C., Lamberson, S., Bora, N., and
harvesting forest biomass energy is about 14 times more
Lee,K.“Energyinputsincropproductionindevelopinganddeveloped
hazardous than coal and oil mining. countries,” J. Agr. Environ. Ethics, in press.
Ethanol production using grains and other food material Pimentel, D., and Kounang, N. (1998). “Ecology of soil erosion in
for gasohol can be expected to have a significant negative ecosystems,” Ecosystems 1, 416–426.
impact on social and economic systems. A major ethanol Pimentel, D., and Krummel, J. (1987). “Biomass energy and soil erosion:
Assessment of resource costs,” Biomass 14, 15–38.
program would help fuel inflation by raising food prices to
Pimentel, D., and Pimentel, M. (1996). “Food, Energy and Society,”
the consumer. In addition, “burning food” as ethanol in au- Colorado University Press, Boulder, Colorado.
tomobiles has serious political and ethical considerations. Pimentel, D., and Strickland, E. L. (1999). “Decreased rates of allu-
In conclusion, the conversion of biomass to provide an vial sediment storage in the Coon Creek Rasin, Wisconsin, 1975–93,”
energy source has some potential to contribute to world Science 286, 1477–1478.
Pimentel, D., Rodrigues, G., Wang, T., Abrams, R., Goldberg, K.,
energy needs, but the associated environmental, health, so-
Staecker, H., Ma, E., Brueckner, L., Trovato, L., Chow, C.,
cial, and economic problems must be carefully assessed. Govindarajulu, U., and Boerke, S. (1994). “Renewable energy: eco-
The foremost priority is the supply of food. Especially nomic and environmental issues,” BioScience 44, 536–547.
vital to this goal is maintaining an ample supply of fer- Pimentel, D., Warneke, A. F., Teel, W. S., Schwab, K. A., Simox, N. J.,
Ebert, D. M., Baenisch, K. D., and Aaron, M. R. (1988). “Food versus
tile cropland needed to feed the rapidly growing world
biomass fuel: Socioeconomic and environmental impacts in the United
population.
States, Brazil, India, and Kenya,” Adv. Food Res. 32, 185–238.
Shapouri, H., Duffield, J. A., and Graboski, M. S. (1995). “Estimating the
Net Energy Balance of Corn Ethanol,” Agricultural Economic Report,
Washington, DC.
ACKNOWLEDGMENT
Tripathi, R. S., and Sah., V. K. (2000). A biophysical analysis of material,
labour and energy flows in different hill farming systems of Garhwal
I sincerely thank the following people for reading an earlier draft of this Himalaya, “Agriculture, Ecosystems and Environment,” in press.
article and for their many helpful suggestions: Andrew R. B. Ferguson, WHO (1996). “Micronutrient Malnutrition—Half of the World’s Popu-
Optimum Population Trust, U.K.; Marcia Pimentel, Division of Natural lation Affected,” No. 78, 1–4, World Health Organization.