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

The Future of Food, Health & the Environment of a Full Earth

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Within two or three generations, the world’s population – currently seven billion people – will level off between ten and eleven billion people. Already our population growth rate, though still positive, is steadily declining as we approach our maximum Earth density; in short, the world is about to be full.

What will that planet look like? Can we provide eleven billion people with a secure supply of nutritious food? Is it possible for so many people to occupy Earth without destroying its remaining ecosystems or doing irreparable damage to its climate? And what are the implications of increasing global incomes, urbanization, and subsequent changes in diet on the physical health of humankind?

These are some of the questions addressed in the Fall 2015 issue of Dædalus. Guest editor David Tilman has organized the issue’s eight essays around the themes of agricultural growth and development, dietary changes, human health (including obesity and undernourishment), and the sustainability of our environment. The issue also examines the ethics and value systems needed to ensure equity and well-being across future generations.

A high-diversity tropical rainforest represents the type of ecosystem that Earth will lose if diets and agricultural practices continue on their current paths. Photograph by Rhett A. Butler for Mongabay.
A high-diversity tropical rainforest represents the type of ecosystem that Earth will lose if diets and agricultural practices continue on their current paths. Photograph by Rhett A. Butler for Mongabay.

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

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.

Authors G. David Tilman and Michael Clark

Invisible Women

Women are ubiquitous and critical to the nutritional well-being of their families, yet they are often invisible to policy-makers, public officials, community leaders, and researchers. Effecting significant decreases in the number of hungry poor people, as well as the improvement of nutritional and economic outcomes, requires policy in addition to operational and research priorities that are directed at the needs of women and girls.

Food, Health & the Environment: A Global Grand Challenge & Some Solutions

The dual burden of obesity and undernutrition is a significant public health challenge worldwide, especially in the context of a changing climate. This essay presents the most recent nutritional evidence for the optimal diet for long-term health, and offers some commentary on how production of these foods affects the environment.

Authors Jaquelyn L. Jahn, Meir J. Stampfer, and Walter C. Willett

Closing Yield Gaps: Consequences for the Global Food Supply, Environmental Quality & Food Security

The social, economic, and environmental costs of feeding a burgeoning and increasingly affluent human population will depend, in part, on how we increase crop production on under-yielding agricultural landscapes, and by how much. Such areas have a “yield gap” between the crop yields they achieve and the crop yields that could be achieved under more intensive management.

Authors Nathaniel D. Mueller and Seth Binder

Land for Food & Land for Nature?

Opinions on how to limit the immense impact of agriculture on wild species are divided. Some think it best to retain as much wildlife as possible on farms, even at the cost of lowering yield (production per unit area). Others advocate the opposite: increasing yield so as to limit the area needed for farming, and then retaining larger areas under natural habitats. Still others support a mixture of the two extremes, or an intermediate approach.

Authors Andrew Balmford, Rhys Green, and Ben Phalan

A Sustainable Agriculture?

The defining challenge of sustainable agriculture is the production of food and other agricultural products at an environmental cost that does not jeopardize the food security and general welfare of future generations. Feeding another three billion people in the face of climate change, biodiversity loss, and an environment already saturated with excess nitrogen and other reactive pollutants requires new approaches and new tools in the design and deployment of workable solutions.

Author G. Philip Robertson

The Ethics of Food, Fuel & Feed

As the collective impact of human activity approaches Earth's biophysical limits, the ethics of food become increasingly important. Hundreds of millions of people remain undernourished, yet only 60 percent of the global harvest is consumed by humans, while 35 percent is fed to livestock and 5 percent is used for biofuels and other industrial products.

Author Brian G. Henning