Surely it is in no one's interest that hunger afflicts nearly a billion people. Yet local, national and global priorities and policies, however well intentioned, often conflict with one another and can thwart solutions, or make things worse. To shed light on the complexities of feeding the world, 19 Stanford experts, including 13 Stanford Woods Institute-affiliated researchers, have joined forces in The Evolving Sphere of Food Security (Oxford University Press, August). Edited by William Wrigley Senior Fellow Rosamond Naylor (Environmental Earth System Science), director of the Center on Food Security and the Environment (FSE), the book's 14 chapters draw on the authors' wealth of experience in a dozen fields including agricultural and developmental economics, environmental and earth sciences, law, medicine, engineering, education and public policy.

Indeed, Naylor says, the conviction that many disciplines must be enlisted together to grapple effectively with world hunger sets this volume apart from others on the subject. She's especially pleased that Stanford's interdisciplinary strengths made it possible to carry out the project in-house. FSE is housed jointly within the Freeman Spogli Institute for International Studies and the Stanford Woods Institute for the Environment; two of their respective directors, Mariano-Florentino Cuéllar and Barton Thompson, are among the authors.

Development professionals define "food security" as affordable access to a stable supply of food that is sufficiently nutritious, not just caloric. That might sound like a straightforward formula—and one that should be feasible, since enough food is produced globally to feed the world's population. Instead, food insecurity seems nearly insurmountable when, as the authors demonstrate through research and fieldwork around the world, the puzzle has so many interlocking pieces: land, water, climate, energy, health, politics.

The Poorest Billion

Affordability is the most obvious challenge. As Woods Senior Fellow, emeritus, Walter Falcon (Freeman Spogli Institute for International Studies) writes, citing World Bank statistics, 27 countries "had average per capita incomes of less than $700 in 2010. At less than $2 per person per day, it is extraordinarily difficult to maintain adequate diets, even when two-thirds or more of the income goes for food." He points out an irony: Although most of the poorest billion people live in rural areas and grow crops, "the bulk of the poor are net purchasers of food, even if they are farmers. Their plots of land are too small, their yields too low, and their labor productivity too constrained to produce enough food for their typically large families."

Ill health is a huge obstacle. In regions plagued by HIV/AIDS or other diseases, families are often too enfeebled to work fields or haul water. Moreover, malnutrition in itself creates a domino effect. Naylor cites reports from the U.N.'s Food and Agriculture Organization showing that 2 to 3 billion people suffer from Vitamin A, iodine and iron deficiencies leading to anemia, goiter, night blindness and other maladies. This so-called hidden hunger impairs people's learning capacities and mental abilities, which in turn reduces their productivity and incomes in a self-perpetuating cycle of poverty.

Falcon, deputy director of the Center on Food Security and the Environment, has much to say about breaking that cycle in his chapter, "Food Security for the Poorest Billion: Policy Lessons from Indonesia." He describes that country's dramatic achievement in alleviating hunger during his three decades as a policy adviser to the Soeharto administration (1967-1998). In addition to sound macroeconomic policies and Green Revolution technologies, he credits the regime's insistence on improving peasants' micro-scale agriculture and their general welfare—notably by setting up rural health and family planning clinics—as crucial to food security.

Without such priorities, steps taken to boost development can sharpen income inequalities. Naylor and visiting research fellow Whitney L. Smith discuss the recent upsurge of large land acquisitions by foreign investors and national elites in Sub-Saharan countries. The hope is that commercial-scale agriculture will provide food security through increased production, supply chain development and job creation. But land rights in these countries are an ill-defined and arbitrarily applied hybrid of tradition and legislation, leaving smallholders at risk of being dispossessed without compensation or substitute employment.

Too Much of a Good Thing?

Some solutions to food insecurity are environmentally harmful. Conversely, some measures taken to protect the environment can be detrimental to food security. How to reconcile the two is a major concern of this book.

For example, fertilizer is fundamental to increasing crop yields and, as Woods Senior Fellows Pamela Matson, dean of the School of Earth Sciences, and Peter Vitousek, biological sciences professor, note, some rapidly developing countries use "truly massive amounts." Some of it degrades into the environment as nitrous oxide, a greenhouse gas several hundred times more potent than carbon dioxide. (Paradoxically, extreme weather produced by greenhouse gases reduces crop yields.) Deforestation caused by expansion of agricultural land adds to the cruel dilemma for policy makers: hunger vs. global warming. The good news—and there is some amid the gloomy scenarios—is that experiments conducted by Matson and Vitousek in Mexico and China show that using less fertilizer more efficiently can reduce costs, improve yields and help the environment.

Energy demands also intersect with environmental concerns, and the mandated boom in biofuels (see graph above) has an especially dramatic impact on agriculture. Growing corn, sugar and vegetable oils to produce them diverts land and water from food crops and livestock feed. (Some 40 percent of U.S. corn goes to ethanol production.)

Although U.S. and E.U. farm incomes have risen as a result, so have food prices in global markets. Naylor, associate professor of environmental earth system sciences David Lobell and biology professor Chris Field analyze in detail how energy, climate and food concerns pose complex policy challenges. In all, The Evolving Sphere of Food Security doesn't present solutions; it offers a blueprint for how to tackle the problems more comprehensively.