Strategies for Energy Use Ener y eiciency can reconcile environmental concerns with economic develo p ment for all nations. It can stretch ener y su pp lies, slow cimatic changes and buy time to develo p alternative ener y resources by John H. Gibbons, Peter D. Blair and Holly L. Gwin E nergy fosters human actiity. It cooks our food, fuels our trans· portation system, heats and cools our buildings and powers our industries. Energy helps to sustain a way of life that includes good health, rewarding employment and leisure time. The standard of living enjoyed by the U.S., Japan, West Germany and other industrialized nations results in large part from energy access: one ifth of the world's population con sumes more than 70 percent of the world's commercial energy. Yet the industrialized world's energy intensi ty-the amount of energy used to pro duce a unit of gross national prod uct-fell by one ifth between 1973 and 1985. In the U.S. the gross national product grew 40 percent while energy consumption remained constant. The most rapid growth in energy consumption now occurs in develop ing countries. As they seek to indus trialize, raise standards of liing and accommodate population growth, the less developed countries, such as Chi na, Mexico and India, must expend more energy. Between 1980 and 1985, population in less developed coun tries grew by 11 percent and energy consumption grew by 22 percent; cor- JOHN H. GmBONS, PER D. BR and HOlY L . GIN explore energy·policy options at the Congressional Oice of Technology Assessment. Gibbons has been the director of the agency for the past decade. He was educated at Ran· dolph-Macon College and Duke Univer sity, where he got his Ph.D. in nuclear physics. Gibbons joined the Oak Ridge National Laboratory in 1954 and lat er directed its environmental program. Blair is manager of the energy and mate rials program at the agency. He earned his B.S. in engineering from Swarthmore College and his Ph.D. from the Universi ty of Pennsylvania, where he now holds an adjunct faculty appointment. Gin is the agency's general counsel. Her under graduate and law degrees are from the University of Tennessee. responding numbers for the indus trialized world were 3 and 5 percent. Even so, less developed countries st,ill consume four to seven times less en ergy per person than do the industrial ized countries. Worldwide energy demand increas es even as knowledge of how ener y use threatens the global environ ment grows. Coal and oil combustion produces acid rain, which damages lakes, forests, structures and crops in Europe and North America. Nuclear ission produces long-lived radioac tive wastes. Automobiles ill the air with smog, which threatens health and property throughout the indus trialized world. Energy consumption dumps more than ive billion tons of carbon into the atmosphere each year. The resulting accumulation of carbon dioide, coupled with other green house gases, could warm the globe several degrees by the middle of the next century, altering the earth's cli mate at a rate from 10 to 100 times faster than the rate of climatic change at the end of the last ice age. We seem to be playing out an an cient myth. Prometheus stole ire and wound up chained to a rock, lashed by the seas and burned by the sun. We have captured the power of fossil fuels, and our penalty is the loss of personal and environmental health. We can change the story. Technolog ical ingenuity can dramatically reduce the amount of energy required to pro vide a given level of goods and servic es, simultaneously cutting down on energy-driven problems. Investments in energy eiciency can help us reduce fossil-fuel demand without sacriiCing economic growth. Application of eist ing eiciency technologies can save investment capital, buy time for the development of new supply technol ogies and ultimately make it possible to provide a higher level of goods and services at a given level of energy consumption. In the following discus sion we consider the possibilities for 136 SCIENTIFIC AMERICN September 1989 new energy resources and increased eiCiency. We emphasize eiciency as our best hope. H umankind expends in one year an amount of fossil fuel that it took nature roughly a million years to produce. Global enery con sumption rose from 21 exajoules in 1900 to 318 exajoules in 1988. (n exajoule is 1018 joules, approimately one quadrillion British thermal units, or the heat that would be released by burning 170 million barrels of crude oil.) Coal, oil and natural gas supply 88 percent of global enery, and nu clear energy proides most of the rest. Many less developed countries still depend heavily on noncommercial fu els, such as wood, dung and crop wastes, but as their economies devel op, they rely increaSingly on fossil fuels for commerce and industry. Oil dominates energy markets, ac counting for 38 percent of commer cial energy consumption. The Organi zation of Petroleum Exporting Coun tries (OPEC) controls three quarters of proved crude-oil reserves, including all recent additions. Reserve estimates have been revised downward for non OPEC nations, including the Soviet Un ion, which consumes 15 percent of world oil and has been increasing its production rates. Dependence on Middle East oil strains the economies of both the less developed and the industrialized world. Expenditures for oil imports have hampered the developing world's eforts to gain hard currency and re pay debts. In 1987 the U.S. imported $40 billion worth of oil, an amount equal to one third of the country's trade deicit. During the same year, the Pentagon spent $15 billion to protect oil supplies. As the Soviet Union, the U.S. and other non-OPEC nations de plete their oil reserves, the geopolitiCS of energy will once again focus on the Middle East. Natural gas provides a ifth of all © 1989 SCIENTIFIC AMERICAN, INC