Hunger touches the lives of people throughout the world, from the affluent Bay Area to the most impoverished regions of rural Africa. Food security – the availability of plentiful, nutritious, and affordable food – is a pressing issue for rich and poor countries alike as the world population moves toward 9 billion by mid-century.

In her new book The Evolving Sphere of Food Security (Oxford University Press, August), Professor Rosamond Naylor takes a holistic approach to the question of how to feed the world. Naylor, a professor of environmental earth system science and director of the Center on Food Security and the Environment (FSE), convened 18 colleagues from across Stanford’s diverse disciplines to shed light on the interdependent issues that affect global food security.

Throughout its 14 chapters, and a foreword by former United Nations Secretary-General Kofi Annan, the book takes up two important questions: How does the challenge of achieving food security change as countries develop economically? And how do food and agriculture policies in one country affect nutrition, food access, natural resources and national security in other countries?

Collaboration across disciplines

Naylor, who edited the volume and co-authored several chapters, explained that The Evolving Sphere of Food Security is the first book of its kind to engage faculty and scholars from across Stanford’s campus on issues of global hunger.

Professor Rosamond Naylor

“This book grew out of a recognition by Stanford scholars that food security is tied to security of many other kinds,” said Naylor, who is also William Wrigley Senior Fellow at the Freeman Spogli Institute for International Studies and the Stanford Woods Institute for the Environment. “Food security has clear connections with energy, water, health, the environment and national security, and you can’t tackle just one of those pieces.”

Stanford has a long history of fostering cross-disciplinary work on global issues. It is in this spirit that the idea for the book was born, Naylor said. The book weaves together the expertise of authors from the fields of medicine, political science, engineering, law, economics and climate science.

“Stanford was the ideal place for this project. A book like this exemplifies how collaborative, interdisciplinary research can be greater than the sum of its parts,” Naylor said. “We have painted a much more inclusive picture of food security than if we had approached these questions from only one discipline.”

Rooted in field research

Another unique feature of the book is that each author’s insights are shaped by years of hands-on research and policymaking experience around the world.

Several authors, for example, have been instrumental in shaping U.S. and global food policy for decades. Walter Falcon, professor emeritus of economics and the deputy director of FSE, traces his career as an agricultural economics advisor to the Indonesian government, where he witnessed the country’s dramatic improvements in combating hunger and poverty since the 1960s.

Political science professor Stephen Stedman recounts his experience as a security policy advisor to the United Nations during the 2000s. Recognizing that food insecurity can exacerbate civil conflict, weaken governments and threaten international stability, Stedman worked to integrate food security into traditional security agendas.

Other authors have spent many years working in East Asia, Africa, South America, the Middle East and Europe. As a whole, said Naylor, the team has conducted well over a hundred years’ worth of field research all over the world.

Challenges evolve as countries develop

A recurring theme throughout the book – also reflected in its title – is the evolving nature of the food security challenges countries face as they move through stages of economic growth. At low levels of development, countries struggle to meet people’s basic needs. For example, Naylor’s chapter on health, co-authored with Eran Bendavid (medicine), Jenna Davis and Amy Pickering (civil and environmental engineering), describes a recent study showing that poor nutrition and rampant disease in rural Kenya is closely tied to contaminated, untreated drinking water. Addressing these essential health and sanitation issues is a key first step toward food security for the poorest countries.

As nations rise above the bottom rungs of development, they encounter new challenges. Scott Rozelle, director of the Rural Education Action Program, warns that middle income countries like China now face a “second food security crisis” of widespread micronutrient deficiency. Recent rapid economic and agricultural advancements have largely solved the problem of supplying sufficient calories. But this progress masks what Rozelle describes as “hidden hunger,” or a lack of vitamins and minerals that impedes kids’ school performance and could slow China’s long-term growth. Even in rich countries like the U.S., said Naylor, malnutrition can be a drag on educational and economic performance.

Developed countries face other unique tradeoffs in the use of resources for food production. In his chapter on water institutions, Buzz Thompson, professor of law and co-director of the Woods Institute, explains that conflicts over water increase between smallholder and industrial users as countries develop. Eric Lambin, professor of environmental earth system science, and Ximena Rueda, research associate in earth sciences, offer the paradox that as countries grow wealthier, changing patterns of agricultural land use may actually worsen food security by fueling the spread of obesity and diabetes.

At its core, said Naylor, The Evolving Sphere of Food Security is about more than economic and policy trends. “The book puts a human face to food security, because hunger is an intensely human experience,” she said. “This book tells an integrated story about people’s lives, and how they are shaped by resource use and the policy process around global food security.”

According to a new study co-authored by Stanford professor David Lobell, the chance of a worldwide slowdown in agricultural yield growth in the next two decades is significantly higher due to global warming.

Lobell and co-author Claudia Tebaldi, a senior researcher at the National Center for Atmospheric Research, set out to estimate the odds of a steep drop in global wheat and corn yield progress under several climate scenarios. The study, “Getting caught with our plants down: the risks of a global crop yield slowdown from climate trends in the next two decades” appeared in Environmental Research Letters.

Lobell said he was motivated to pursue the study based on questions posed by stakeholders and decision makers in governments and the private sector.

“I’m often asked whether climate change will threaten food supply, as if it’s a simple yes or no answer,” Lobell said. “The truth is that over a 10 or 20 year period, it depends largely on how fast the Earth warms, and we can’t predict that very precisely. So the best we can do is try to determine the odds.”

Lobell and Tebaldi calculated the chance of a 10 percent global yield loss from climate change over the next 20 years, which would represent a severe impact on food supply, enough to roughly halve the rate of yield growth.

The short time frame of the study was deliberate, Lobell said. “Many studies have looked at climate and agriculture trends over the coming 50 or 100 years. But the next two decades are when most of the global population growth, and dietary shifts driven by a growing middle class, will occur. The growth rate of food demand will be higher during this time than at any other time in the next century.”

Without human-induced global warming – in other words, in a world with only natural climate variability – the likelihood of a yield drop that large is only 1 in 200. But when the team accounted for global warming, they saw the odds jump to 1 in 10 for corn and 1 in 20 for wheat. “In this study, we did not try to estimate the most likely impacts of climate change on crops,” Lobell said. “Rather, we estimated the likelihood of a really major impact, not because we want to scare people, but because there are many people who want to be prepared for all contingencies.”

“The point of the paper is to move from hand-waving about scenarios of what could go wrong, to specific and transparent estimates of the actual odds,” Lobell said. “The odds are not very high, but they are significant and a lot bigger than they used to be. The people asking these questions are accustomed to planning for scenarios with much less than a 10 percent chance of happening, so it will be interesting to see whether this study has any effect on how they operate.”

Lobell adds that organizations working toward global food security, and related issues such as conflict prevention, are most interested in the next 20 years because their decisions rarely consider the more distant future.  “As scientists, we might prefer to work on time scales in which the answers are clearer, but we also want to be responsive to the actual concerns and questions that decision makers have.”

Lobell is associate professor of Environmental Earth System Science at Stanford and associate director of the Center on Food Security and the Environment. He is also a senior fellow at the Stanford Woods Institute for the Environment and the Freeman Spogli Institute for International Studies.

Contact:

David Lobell: dlobell@stanford.edu

Laura Seaman, Communications and External Relations Manager, Center on Food Security and the Environment: lseaman@stanford.edu

Has the global food price bubble  burst, and if so, does it matter? In the first installment of FSE's new Food and Nutrition Policy Symposium Series, Professor Thomas Hertel of Purdue University and Professor Johann Swinnen of Leuven University outlined global trends in the cost of food, and explained how a drop in prices after the food price shocks of 2007-2008 might affect global politics and economics.

What drives food prices?

As population growth and rising incomes put pressure on the global food supply, many scholars consider high food costs to be the "new normal," especially following the food price shocks of 2007-2008. Professor Thomas Hertel challenged this view, saying that "To look forward 45 years, you have to look back 45 years" at what factors actually impact food prices.

Prices for many food commodities fell between 1961 and 2006, despite strong population and income growth, because the world was able to triple crop production during the same period. Since the recent price spikes, the "food price bubble" seems to have burst, with prices falling steadily since 2009.

Although population will continue to grow over the next several decades, the rate of growth is slowing worldwide and is mostly concentrated in developing countries, where per capita purchasing power is relatively low. This minimizes the pressure that population growth puts on the global food supply.

Economic factors may be more influential. "For the first time in history," Hertel said, "income will surpass population as a driver of global food demand." As countries move up the income scale, they consume richer diets of input-intensive products like meat, dairy and processed foods.

Energy prices also influence global food costs. As oil and gas prices rise, demand grows for alternative fuels like ethanol. Half of the increase in corn production over the past several decades came from the growing demand for ethanol, which was fueled by government mandates and which drove up the global price of corn. These mandates have been rolled back in recent years, however, and demand growth for biofuels has waned.

Hertel added that issues around climate change, urbanization, water supply, food waste and deforestation may also impact global food prices in the future.

Many scholars point to crop yields as a way to close the gap between food supply and demand and keep prices low. But Hertel cautioned that scientists and policymakers may be constrained by technical and economic limits.

To further increase yields "is a bigger job than simply doing some more science in the lab," Hertel said. But he noted with optimism that new investments in research and development have risen sharply from both the public and private sector, particularly in countries like China, India and Brazil where food security is a pressing issue. 

Impacts of the food price bubble

Professor Johann Swinnen explained that if the food price bubble has in fact burst, the next several years are likely to bring a shift in the politics and economics of global food issues.

The recent bubble coincided with an increase in both policy attention and donor funding to combat food insecurity - a focus that has benefitted both farmers and consumers, but that could wane as prices fall.

While the high prices of 2007-2008 benefited farmers, they in turn hurt low-income consumers in urban areas. And because people in high-density areas find it easier to organize and voice their concerns over government policies, they are more likely to capture media attention.

This "urban bias," as Swinnen described it, influenced policymakers to respond to the heavy media coverage. His team found that after 2007, agricultural funding from the World Bank, United Nations Food and Agriculture Organization (FAO) and the International Maize and Wheat Improvement Center (CIMMYT) all rose sharply. The percentage of global development aid targeted toward agriculture also grew.

Swinnen described the social and political conditions of 2007-2008 as a "perfect storm" that shifted the attention of policymakers toward global food security investments. Paradoxically, Swinnen explained, this policy response to urban unrest over food prices ultimately benefitted both rural and urban populations, by boosting agricultural investments for food producers while also helping lower costs for consumers.

 The Food and Nutrition Policy Symposium Series will run for three years and will consist of a total of ten lectures spanning a wide range of issues around global food and nutrition policy. It is funded by Zachary Nelson, '84 and Elizabeth Horn. The series follows on the successful two-year Global Food Policy and Food Security Symposium Series which concluded in May 2013 and was funded by the Bill and Melinda Gates Foundation.

Corn yields in the central United States have become more sensitive to drought conditions in the past two decades, according to a new study in the journal Science from a team led FSE associate director David Lobell.

"The Corn Belt is phenomenally productive," Lobell said, referring to the region of Midwestern states where much of the country's corn is grown. "But in the past two decades we saw very small yield gains in non-irrigated corn under the hottest conditions. This suggests farmers may be pushing the limits of what's possible under these conditions."

He predicted that at current levels of temperature sensitivity, crops could lose 15 percent of their yield within 50 years, or as much as 30 percent if crops continue the trend of becoming more sensitive over time.

As Lobell explained, the quest to maximize crop yields has been a driving force behind agricultural research as the world's population grows and climate change puts pressure on global food production. One big challenge for climate science is whether crops can adapt to climate change by becoming less sensitive to hotter and drier weather.

"The data clearly indicate that drought stress for corn and soy comes partly from low rain, but even more so from hot and dry air. Plants have to trade water to get carbon from the air to grow, and the terms of that trade become much less favorable when it's hot," said Lobell, also the lead author for a chapter in the U.N. Intergovernmental Panel on Climate Change (IPCC) Fifth Assessment Report, which details a consensus view on the current state and fate of the world's climate.

Rain, temperature, humidity

The United States produces 40 percent of the world's corn, mostly in Iowa, Illinois, and Indiana. As more than 80 percent of U.S. agricultural land relies on natural rainfall rather than irrigation, corn farmers in these regions depend on precipitation, air temperature and humidity for optimal plant growth.

According to the research, over the last few decades, corn in the United States has been modified with new traits, like more effective roots that better access water and built-in pest resistance to protect against soil insects. These traits allow farmers to plant seeds closer together in a field, and have helped farmers steadily raise yields in typical years.

But in drought conditions, densely planted corn can suffer higher stress and produce lower yields. In contrast, soybeans have not been planted more densely in recent decades and show no signs of increased sensitivity to drought, the report noted.

Drought conditions are expected to become even more challenging as temperatures continue to rise throughout the 21st century, the researchers said.

Lobell said, "Recent yield progress is overall a good news story. But because farm yields are improving fastest in favorable weather, the stakes for having such weather are rising. In other words, the negative impacts of hot and dry weather are rising at the same time that climate change is expected to bring more such weather."

Extensive data

Lobell's team examined an unprecedented amount of detailed field data from more than 1 million USDA crop insurance records between 1995 and 2012.

"The idea was pretty simple," he said. "We determined which conditions really matter for corn and soy yields, and then tracked how farmers were doing at different levels of these conditions over time. But to do that well, you really need a lot of data, and this dataset was a beauty."

Lobell said he hopes that the research can help inform researchers and policymakers so they can make better decisions.

"I think it's exciting that data like this now exist to see what's actually happening in fields. By taking advantage of this data, we can learn a lot fairly quickly," he said. "Of course, our hope is to improve the situation. But these results challenge the idea that U.S. agriculture will just easily adapt to climate changes because we invest a lot and are really high-tech."

Lobell and colleagues are also looking at ways crops may perform better under increasingly hot conditions. "But I wouldn't expect any miracles," he said. "It will take targeted efforts, and even then gains could be modest. There's only so much a plant can do when it is hot and dry."

This animation shows the increasing sensitivity of U.S. corn to drought over time. Animation by Carlo Di Bonito.

Growing agave and other carefully chosen plants amid photovoltaic panels could allow solar farms not only to collect sunlight for electricity but also to produce crops for biofuels, according to new computer models by Stanford scientists.

This colocation approach could prove especially useful in sunny, arid regions such as the southwestern United States where water is scarce, said Sujith Ravi, who is conducting postdoctoral research with professors David Lobell and Chris Field, both on faculty in environmental Earth system science and senior fellows at the Stanford Woods Institute for the Environment. David Lobell is associate director and Chris Field is a core faculty affiliate at the Center on Food Security and the Environment.

“Colocated solar-biofuel systems could be a novel strategy for generating two forms of energy from uncultivable lands: electricity from solar infrastructure and easily transportable liquid fuel from biofuel cultivation,” said Ravi, lead author of a new study published in a recent issue of the journal Environmental Science & Technology that details the idea.

Photovoltaic (PV) solar farms run on sunlight, but water is required to remove dust and dirt from the panels to ensure they operate at maximum efficiency. Water is also used to dampen the ground to prevent the buildup and spread of dust. Crops planted beneath the solar panels would capture the runoff water used for cleaning the PV panels, thus helping to optimize the land. The plants’ roots would also help anchor the soil, and their foliage would help reduce the ability of wind to kick up dust.

Computer simulations of a hypothetical colocation solar farm in California’s San Bernardino County by Ravi and colleagues suggest that these two factors together could lead to a reduction in the overall amount of water solar farms need to operate. "It could be a win-win situation," Ravi said. “Water is already limited in many areas and could be a major constraint in the future. This approach could allow us to produce energy and agriculture with the same water.”

But which crops to use? Many solar farms operate in sunny but arid regions that are very not hospitable to most food crops. But there is one valuable plant that thrives at high temperatures and in poor soil: agave. Native to North and South America, the prickly plant can be used to produce liquid ethanol, a biofuel that can be mixed with gasoline or used to power ethanol vehicles. "Unlike corn or other grains, most of the agave plant can be converted to ethanol," Ravi said.

The team plans to test the colocation approach around the world to determine the ideal plants to use and to gather realistic estimates for crop yield and economic incentives.

“Sujith’s work is a great example of how thinking beyond a single challenge like water or food or energy sometimes leads to creative solutions,” said Lobell, who is a coauthor on the new study. “Of course, creative solutions don’t always work in the real world, but this one at least seems worthy of much more exploration.”

Ker Than is associate director of communications for the School of Earth Sciences.

Contact: Sujith Ravi, 703-581-8186, sujith@stanford.edu; Ker Than, 646-673-4558, kerthan@stanford.edu 

FSE’s David Lobell finds that an increase of more than two degrees Celsius in average global temperature is likely to cause yields of wheat, rice and maize to fall throughout the 21st century. Early adaptation could increase projected yields by up to 15 percent.

If global temperatures continue to rise, the amount of crops farmers can harvest will sharply decline during the next 100 years.

Stanford professor David Lobell and an international team of climate scientists modeled future crop yields under several global climate scenarios throughout the 21^st century. They found that if average global temperatures rise by more than two degrees Celsius, farmers are likely to get less wheat, rice and maize out of each plot of land. Yields are expected to fall by an average of 4.9 percent for every one degree Celsius rise in average temperature. Year-to-year variability of harvests is also expected to rise, as drought and flooding become more frequent. Crop yield losses will speed up throughout the century, with declines in yield beginning around 2030 and with the fastest drop happening in the second half of the century.

Lobell, an associate professor of Environmental Earth System Science and the associate director of the Center on Food Security and the Environment at Stanford, reviewed over 1,700 published studies with a team of climate scientists from the United States, United Kingdom and Australia. The team found that if farmers adapt to climate change within the next few years, they have a better chance of avoiding or even reversing the predicted decline of wheat and rice yields in some regions. Agricultural adaptation strategies like irrigating fields and developing new crop breeds could increase projected yields between 7 percent and 15 percent.

The new study also highlights the need for better data on the potential future impacts of other factors that affect crop yields, like the prevalence of pests and plant diseases, and the availability of water supply. A full version of the study can be found online at Nature Climate Change.

By Terry Nagel, Stanford Woods Institute for the Environment

David Lobell, an associate professor of environmental Earth system science and a senior fellow at the Freeman Spogli Institute for International Studies, has been named a 2013 MacArthur Fellow and one of Foreign Policy Magazine's 100 Leading Global Thinkers of 2013.

MacArthur "Genius Grant"

Lobell, who is also the associate director of FSI’s Center on Food Security and the Environment, was cited "for unearthing richly informative, but often underutilized sources of data to investigate the impact of climate change on crop production and global food security." He received his doctorate degree from Stanford in 2005 and was appointed to the faculty in 2009.

A pioneer of the emerging field of crop informatics, Lobell is revolutionizing the understanding of the environmental factors controlling crop yields, with a particular emphasis on adaptation to climate change.

His work provides decision makers, for the first time, with critical information about how to adapt agricultural development to climate change.

"I was completely surprised by this recognition, but am really excited by the opportunity it presents," said Lobell, who is also a senior fellow at Stanford Woods Institute for the Environment. "To have the MacArthur Foundation recognize the value of taking new approaches and the importance of the topics of hunger and food production is deeply gratifying."

Lobell's research focuses on identifying opportunities to increase yields of crops including wheat and corn in major agricultural regions, with projects currently underway in Africa, South Asia, Mexico and the United States. 

"I'm interested in how to feed the world and protect the environment at the same time," he said. "While there are many theories about how to do that, my work tries to test these theories, often using data that were collected for completely different reasons."

The citation emphasized Lobell's work on understanding the risks of climate change, and options for adaptation. "Climate change is one of the reasons for concern about feeding people in the future, but it's not insurmountable if good decisions are made," he said. 

When asked how he would use the funding, Lobell said he would not rush the decision. He said that some of the award would likely relieve him of writing grant proposals. In addition, he said he would consider using some toward more travel.

"A lot of my better ideas in the past have started with travel and interactions with international collaborations," he said.  "And there's always a tradeoff between my work travel and family.  I now might take my wife and young sons with me on some extended trips."

Foreign Policy's Leading Global Thinkers

In December, Foreign Policy named Lobell one of the 100 Leading Global Thinkers of 2013. The recognition comes for his work "helping farmers feed the world" in a changing climate. Lobell is joined on the magazine's list by fellow researchers working on climate issues, along with prominent public figures like German Chancellor Angela Merkel, U.S. Secretary of State John Kerry, and Pope Francis.

Widely sought throughout the world to provide expert advice, Lobell is a lead author for the Intergovernmental Panel on Climate Change Fifth Assessment Report chapter on food security, to be published in 2014. The IPCC, which won the Nobel Prize in 2007, also made Foreign Policy's 2013 Leading Global Thinkers list alongside Lobell, "for showing that humanity is on the brink of catastrophe" if climate change is not addressed quickly and aggressively.

Lobell studied applied mathematics at Brown University, and before receiving his bachelor's degree in 2000, he spent the summer of 1999 as a research intern at Stanford, developing remote sensing algorithms. He then pursued graduate studies at Stanford, receiving his doctorate in geological and environmental sciences in 2005.

He was a postdoctoral fellow at Lawrence Livermore National Laboratory from 2005-2007, and returned to Stanford as a senior research scholar in the Program on Food Security and the Environment in 2008-2009.  He accepted an appointment as assistant professor in the Stanford School of Earth Sciences in 2009. 

In addition to his research, Lobell teaches several courses open to both undergraduates and graduate students, including "Feeding Nine Billion," "Climate and Agriculture," and "Global Land Use to 2050," as well as modeling and statistical methods classes.

Lobell received a NASA New Investigator Program Award for 2008-2011. He received the James B. Macelwane Medal from the American Geophysical Union in 2010, awarded for significant contributions to the geophysical sciences by an outstanding scientist under the age of 36.

Nancy Peterson is the chief communications officer for Stanford's School of Earth Sciences. Laura Seaman, communications manager for the Center on Food Security and the Environment, contributed to this article.