An open access publication of the American Academy of Arts & Sciences
Fall 2015

Food, Agriculture & the Environment: Can We Feed the World & Save the Earth?

G. David Tilman and Michael Clark

Secure and nutritious food supplies are the foundation of human health and development, and of stable societies. Yet food production also poses significant threats to the environment through greenhouse gas emissions, pollution from fertilizers and pesticides, and the loss of biodiversity and ecosystem services from the conversion of vast amounts of natural ecosystems into croplands and pastures. Global agricultural production is on a trajectory to double by 2050 because of both increases in the global population and the dietary changes associated with growing incomes. Here we examine the environmental problems that would result from these dietary shifts toward greater meat and calorie consumption and from the increase in agricultural production needed to provide this food. Several solutions, all of which are possible with current knowledge and technology, could substantially reduce agriculture's environmental impacts on greenhouse gas emissions, land clearing, and threats to biodiversity. In particular, the adoption of healthier diets and investment in increasing crop yields in developing nations would greatly reduce the environmental impacts of agriculture, lead to greater global health, and provide a path toward a secure and nutritious food supply for developing nations.

DAVID TILMAN, a Fellow of the American Academy since 1995, is Regents Professor and McKnight Presidential Chair in the College of Biological Sciences and Director of the Cedar Creek Ecosystem Science Reserve at the University of Minnesota. He is also Professor at the Bren School of Environmental Science and Management at the University of California, Santa Barbara. He is the author of Functional Consequences of Biodiversity: Empirical Progress and Theoretical Extensions (with Ann P. Kinzig and Stephen Pacala, 2002), Plant Strategies and the Dynamics and Structure of Plant Communities (1988), Resource Competition and Community Structure (1982), and more than two hundred scientific papers.

MICHAEL CLARK is a Graduate Student in the Department of Ecology, Evolution, and Behavior at the University of Minnesota. He is the author, with David Tilman, of “Global Diets Link Environmental Sustainability and Human Health,” which appeared in Nature 515 (2014).

The importance of food is undeniable. Stable societies require adequate and predictable supplies of food.1  Modern industrial societies require that most of their members have differentiated and specialized skills, which is only possible when high-yielding crops allow a few people to feed the many. Societies also depend on a multitude of services provided by ecosystems, including the production of pure drinking water, the decomposition of wastes, the creation of fertile soils, the removal and storage of much of the greenhouse gasses released by society, the amelioration of flooding provided by intact ecosystems, and the support of a multitude of other species that provide food, crop pollination, timber, fiber, medicines, and the functioning of Earth’s ecosystems.2

Agriculture–as currently practiced–poses major threats to the environment. Agriculture and food production are responsible for more than 25 percent of total global greenhouse gas (GHG) emissions to .  .  .


  • 1Christopher B. Barrett, Food Security & Sociopolitical Stability (Oxford: Oxford University Press, 2013), 512.
  • 2Gretchen C. Daily, Stephen Polasky, Joshua Goldstein, Peter M. Kareiva, Harold A. Mooney, Liba Pejchar, Taylor H. Ricketts, James Salzman, and Robert Shallenberger, “Ecosystem Services in Decision Making: Time to Deliver,” Frontiers in Ecology and the Environment 7 (2009): 21–28.
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