DECEMBER 13, 2013
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About the Authors:
Barbara Boyle Torrey has been a Visiting Fellow at the Population Reference Bureau. She was previously Executive Director of the Division of Behavioral and Social Sciences at the National Research Council. She was also Chief of the Center for International Research at the Census Bureau and an economist at the Office of Management and Budget. She edited Population and Land Use Change for the National Academy Press as well as two other books and has published a number of articles on international population and income trends. She did her undergraduate and graduate work at Stanford University’s Food Research Institute. She is a member of the National Research Council’s Committee on Population.
E. Fuller Torrey is the Executive Director of the Stanley Medical Research Institute in Chevy Chase, Maryland, and Professor of Psychiatry at the Uniformed Services University of the Health Sciences. He received an AB from Princeton University, a MD from McGill University, and a Master’s in Anthropology and training in Psychiatry at Stanford University. He spent two years as a Peace Corps physician in Ethiopia and has returned there several times. He has published more than 200 professional papers and 20 books, including Beasts of the Earth: Animals, Humans, and Disease with Robert Yolken. The Roots of Treason, his biography of Ezra Pound, was nominated as one of the five best biographies of 1983 by the National Book Critics Circle. He is married to Barbara Boyle Torrey, an economist.
Population Increases and Agricultural Productivity
The race between expanding agricultural productivity and increasing human populations began in the Middle East 11 millennia ago. The Neolithic agricultural transition from foraging to agriculture caused a demographic transition from low fertility to higher fertility rates. And then shortly after the beginning of agriculture, mortality rates also increased because of zoonotic and other infectious diseases. The small net difference between the increasing Neolithic fertility and mortality rates led inexorably to an increasing world population.
At the beginning of the Neolithic transition there was about 5 million people on earth; at the beginning of the Industrial Revolution, there was 1 billion. And just as agriculture had caused the first demographic transition, industrialization caused the second. Although the 19th Century populations in industrializing countries continued to grow their fertility and mortality rates began to fall. Today, the populations in 19 of these countries are actually declining in absolute numbers.
It was only in the 1960s, however, when the demographic transition began in the non-industrial countries. It was in these countries where the race between agriculture and people has become most intense. Fortunately, the agricultural sciences have produced one of the most important scientific success stories in the world, especially in many of the developing countries. Only one major area of the world is not yet feeding its populations.
Africa probably grows enough to feed its population today, but the food is not well distributed either spatially or temporally. In addition, the demographic transition in Africa has unexpectedly stalled, which means that there will be more people in the future than planners were counting on even two years ago. Therefore, although the race between increasing population size and agricultural productivity began in the Middle East 11 millennia ago, its conclusion is likely to be determined in Africa in the next half century.
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