When it comes to climate change and its impacts on agriculture, we may know less than we think.

But according to David Lobell, Assistant Professor in Stanford’s Department of Environmental Earth System Science, acknowledging the gaps in our understanding could help us to more effectively prepare the world’s food system for a warmer future.

Lobell, who has built an impressive career around the study of climate change and its implications for global food security, addressed the topic of agricultural adaptation during a two-hour symposium held on the Stanford campus in early December. His presentation summarized the strengths and weaknesses of climate models in the context of global agriculture, and suggested broad strategies for preparing agriculture for climate change’s inevitable impacts.

Lobell began his talk by reaffirming some common beliefs. The Earth as a whole is unquestionably warming, he said. Precipitation intensity is increasing in high-rainfall areas, and the world’s driest regions are becoming drier.

“Think about the hottest day we currently experience in a 20-year period,” Lobell told listeners. “By mid-century, we’ll be seeing that hottest day every year, as opposed to every 20 years.” During the same period, soil moisture content in many of the world’s major agricultural areas will decrease by as much as 10 to 15 percent, while annual precipitation at the equator and high latitudes will increase by several inches per year.

At the global scale, Lobell said, climate change will have a net negative impact on existing agricultural systems. The world’s rainfed farms will become increasingly vulnerable to heat and water stress.  Growing ranges and seasons for heat-intolerant crops, such as wheat and sorghum, will contract. Although the high latitudes may see some gains from warmer temperatures and CO2 fertilization of certain crops, low-latitude regions – including South Asia and much of Africa – will suffer disproportionate yield losses as temperatures rise.

However, Lobell said that impacts aimed at local and national scales, as opposed to broad regions or the world as a whole, are much more difficult to predict. A moderate change in average rainfall across a continent could translate to drastic increases or decreases in individual countries. For example, while climate models suggest that Africa’s annual rainfall will change by less than 10 percent over the next 50 years, model projections show rainfall in the nation of Sengal changing by anywhere from five to 40 percent over the same period.

Additionally, Lobell said, forecasts of increasing climate variability are frequently overstated. “The number one misperception I hear is that climate change is going to mean more variability,” he noted.  In fact, model projections of year-to-year variability in temperature and precipitation cover a wide range. Some models do show large increases in variability over the next century – but others show a slight decrease.

Because we understand climate impacts best at the long-term and global scales, Lobell said, global responses that address long-term trends are the most likely to serve our future needs. He cautioned against approaches that prepare farmers for short-term variability, such as sudden floods or droughts, but fail to acknowledging the effects of steadily rising average temperatures. He also stressed the value of globally coordinated efforts, particularly those aimed at developing better heat and drought-tolerant crop varieties, to supplement local infrastructure projects.

 “We’re in a world where local resilience depends on global systems,” Lobell noted. He said that the interconnectedness of modern global food markets makes global trends, and global responses, increasingly relevant for local food security.

At both local and global levels, an effective response to climate change will require robust social institutions. Dr. Fatima Denton, Program Leader for Climate Change Adaptation in Africa for the Consultative Group on International Agricultural research, stressed this point in her comments on Lobell’s presentation. “Climate change has really unmasked our governance challenges and the weaknesses in our institutions,” Denton said. “This is not just about biophysical processes…it’s about the development pathways that we choose.”

Lobell agreed. Climate change, he said, presents “an important opportunity for transformation.” He encouraged present and future leaders to think critically about all aspects of the relevant science and policy. “Be skeptical of what you hear,” he advised, “and educate yourself about what we do and don’t know.”

This was the sixth talk in FSE's Global Food Policy and Food Security Symposium Series.

Stanford’s Center on Food Security and the Environment (FSE) has received a $2 million grant from Cargill, a second gift from the company that raises its total contribution to FSE to $5 million over 10 years.

The announcement was made Nov. 10 at a dinner celebrating the launch of FSE as a full-scale research center. FSE has more than doubled in size in five years. Because of its growth and increasing importance of food security issues at Stanford and worldwide, it became an official center in September.

“The center’s rapid growth would not have been possible without the generous support of Cargill,” FSE Director and William Wrigley Senior Fellow Rosamond L. Naylor said. “Cargill’s initial investment provided seed-funding for the bold, new research and teaching that was happening at FSE while keeping our lights on and the staff running during our critical years of early development.”

A $3 million grant from Cargill in 2008 jump-started a visiting fellows program at FSE and helped build the infrastructure to support the center’s research.

The new grant will continue to provide program support, but will also be used to hire younger faculty and scholars to Stanford to work within the new Center.

Stanford-Cargill partnership

Stanford's partnership with Cargill extends back to 1976 when Cargill endowed Walter P. Falcon, then Director of Stanford's Food Research Institute and now FSE Deputy Director, with the Helen C. Farnsworth Professorship in International Agricultural Policy. The gift was intended to strengthen Stanford's work in agricultural policy, specifically as it relates to the international grain economy. FSI senior fellow Scott Rozelle now holds the Helen C. Farnsworth chair.

FSE and Cargill remain committed to helping feed a growing population while preserving the planet's natural resources. FSE is an applied group focused on providing real solutions to important food and agricultural issues.

“Poverty is the main issue driving food insecurity—it’s a question of access rather than food availability,” Naylor said.

FSE’s partnership with Cargill has demonstrated how Stanford-based research can be relevant to the private sector. FSE is conducting ongoing research on oil palm and land use issues in Indonesia that is helping inform and shape policy. Work on aquaculture feeds in China is another overlapping area of interest, as are ongoing assessments of biofuels in the U.S., Africa and Asia. Both have a stake in better understanding climate change impacts on agriculture and food commodity price volatility.

“It is clear to us at FSE—and increasingly to leadership of Stanford—that global food security will remain a critical issue within international policy circles,” said Naylor. “With support like the grant from Cargill, we are confident that Stanford can play a leading role in shaping the future policy discourse.”

As markets around the world slump, sputter and slump again, China maintains the fastest-growing economy. But despite the country’s boom, it has fallen behind in making sure its children will be healthy, strong and smart enough to cash in on it.

About 30 percent of children living in China’s rural areas are anemic – sick with an iron deficiency that Stanford researcher Scott Rozelle and his colleagues with the Rural Education Action Project have proven leads to bad school performance. And a poor education coupled with anemia’s physical blow puts those kids at risk for lives of poverty and missed opportunities.

But things are changing. Influenced in part by the research Rozelle has conducted and presented to Chinese officials, the government recently launched a policy to improve school lunches for about 20 million children across the country.

The plan invests $2.5 billion a year during the next nine years to ensure the meals are more nutritious for elementary and middle school students. That doubles the amount spent on lunches for China’s neediest children.

“For 5,000 years it was OK to be anemic if you're never going to leave the farm," said Rozelle, an economist and senior fellow at Stanford’s Freeman Spogli Institute for International Studies who is still experimenting with ways to improve children's health in rural China and get the government to adopt the most effective methods.

"But we're looking 20 years into the future where there are much fewer farms and you need at least a high school education to make a living in the city,” Rozelle said. “If you are sick with anemia, it is going to affect your cognitive ability, educational performance and ultimately your chances of going on in school."

Rozelle began studying anemia and its links to school performance in 2008.

After conducting an initial study of about 4,000 primary school students in Shaanxi province, he found that nearly 40 percent of the children were anemic – the result of diets that consisted mostly of rice and noodles in regions where meat, fruit and fresh vegetables are expensive and often hard to come by.

Those survey results were presented to the government in a 2009 policy brief written by Rozelle and his collaborators. Officials adopted the brief, making rural primary school nutrition part of China’s official policy discussion.

A second study conducted between 2008 and 2009 found that anemia rates dropped when schoolchildren were given vitamins fortified with iron. And as their iron levels rose, so did their test scores.

An experiment followed to back up those findings, while another set of large-scale surveys across four provinces reinforced that childhood anemia was indeed a widespread problem.

The findings from those surveys and tests were packaged in another policy brief that was accepted by the government earlier this year, prompting a government directive urging more concrete action in the area of student nutrition.

Those documents, along with several presentations Rozelle has made to government officials and commissions, have culminated in a move to pour $22.5 billion into more nutritious school lunches between now and 2020. It will likely be up to local government and school officials to decide exactly what those meals will include, but Rozelle is hopeful they’ll lead to diets with more meat, vegetables and iron supplements.

“Research-based results are an important avenue for affecting policy in China,” said Chen Zhili, vice chair of the Standing Committee of the National People’s Congress and a former minister of education. “The new programs for child nutrition were only made possible by the work of groups (like the Rural Education Action Project).”

And a national policy aimed at improving nutrition and curbing anemia helps ensure that China maintains its foothold in the world’s economy and grow in a more stable, equitable way, Rozelle said.

“The social return is huge,” Rozelle said. “These kids will be able to do better in school, work harder and sustain China’s growth.”

Fourteen visionary, young trailblazers from around the world — including an astrobiologist, a Middle East peace worker and cultural educator, an Asian elephant specialist, a wastewater engineer, a filmmaker and a science entrepreneur — have been named to the 2011 class of National Geographic Emerging Explorers. Jennifer Burney, a Scripps postdoctoral researcher and FSE fellow helping to understand how changes in cooking habits could have complementary effects on climate change and public health, was named one of them.

The award provides financial support to the research efforts of scientists who are in their early careers. Burney is a University of California President’s Postdoctoral Fellow at Scripps Institution of Oceanography, UC San Diego and is an affiliate of Stanford University's Program on Food Security and the Environment. At Scripps, she is part of a team headed by Professor of Climate and Atmospheric Science Veerabhadran Ramanathan studying the effects of replacing homemade cookstoves in rural India with cleaner-burning alternatives in an effort called Project Surya.

“I love the puzzle of figuring out how to measure something be it with data or instrumentation and Surya by its nature is just a giant web of measurement problems. It’s a really great synergy,” said Burney, who received her doctorate in physics from Stanford University in 2007.

Among Burney’s objectives is to study the links between energy poverty and food and nutrition security and the environmental impacts of food production and consumption. In the case of Project Surya, this will mean helping Ramanathan assess what happens when emissions of soot and other black carbon are substantially reduced in a given area. Ramanathan expects that the experiment will show immediate reduction in the contribution of greenhouse agents from that area. On a large scale, the reduction of such pollution created by use of wood and dung as cooking fuel could have a major mitigative impact on climate change. It could also improve the respiratory health of local residents, who frequently must inhale the smoke from their stoves as they cook in poorly ventilated kitchens.

The Project Surya team is hoping to launch a phase later this year in which cookers are replaced with cleaner stoves in a 10-square-kilometer (four-square-mile) area in India. They will then measure emissions of black carbon via satellite and at ground level with help from local residents.

Burney will separately study the agricultural effects associated with temperature and precipitation changes that could be triggered by the cookstove switch.

“I am really delighted, but not surprised, that Jen got this well deserved honor,” said Ramanathan. “She brings lots of talent and experience to the Surya research. She is an asset.”

Burney said that the award will also support another project she is conducting in West Africa in which she is assessing the feasibility of using solar power to improve irrigation capabilities there.

The Emerging Explorers each receive a $10,000 award to assist with research and to aid further exploration. Burney and the other new Emerging Explorers are introduced in the June 2011 issue of National Geographic magazine, and comprehensive profiles can be found at http://www.nationalgeographic.com/emerging.

Middle class appetites and rising affluence are driving up the price of food in China, home to 1.3 billion people. Growers are faced with rising demand for food just as the rural labor supply dwindles. Yet the changes in food and work preferences aren't all bad, as they reflect the human and economic development taking place in China, says Scott Rozelle, food economist and Helen Farnsworth Senior Fellow at FSI.

Policy brief: Climate trend and global crop production since 1980

Global warming is likely already taking a toll on world wheat and corn production, according to a new study led by Stanford University researchers. But the United States, Canada and northern Mexico have largely escaped the trend.

"It appears as if farmers in North America got a pass on the first round of global warming," said David Lobell, an assistant professor of environmental Earth system science and center fellow at the Program on Food Security and the Environment at Stanford University. "That was surprising, given how fast we see weather has been changing in agricultural areas around the world as a whole."

Lobell and his colleagues examined temperature and precipitation records since 1980 for major crop-growing countries in the places and times of year when crops are grown. They then used crop models to estimate what worldwide crop yields would have been had temperature and precipitation had typical fluctuations around 1980 levels.

The researchers found that global wheat production was 5.5 percent lower than it would have been had the climate remained stable, and global corn production was lower by almost 4 percent. Global rice and soybean production were not significantly affected.

The United States, which is the world's largest producer of soybeans and corn, accounting for roughly 40 percent of global production, experienced a very slight cooling trend and no significant production impacts.

Outside of North America, most major producing countries were found to have experienced some decline in wheat and corn (or maize) yields related to the rise in global temperature. "Yields in most countries are still going up, but not as fast as we estimate they would be without climate trends," Lobell said.

Lobell is the lead author of the paper, Climate Trends and Global Crop Production Since 1980, published May 5 online in Science Express.

Russia, India and France suffered the greatest drops in wheat production relative to what might have been with no global warming. The largest comparative losses in corn production were seen in China and Brazil.

Total worldwide relative losses of the two crops equal the annual production of corn in Mexico and wheat in France. Together, the four crops in the study constitute approximately 75 percent of the calories that humans worldwide consume, directly or indirectly through livestock, according to research cited in the study.

"Given the relatively small temperature trends in the U.S. Corn Belt, it shouldn't be surprising if complacency or even skepticism about global warming has set in, but this study suggests that would be misguided," Lobell said.

Since 1950, the average global temperature has increased at a rate of roughly 0.13 degrees Celsius per decade. But over the next two to three decades average global temperature is expected to rise approximately 50 percent faster than that, according to the report of the Intergovernmental Panel on Climate Change. With that rate of temperature change, it is unlikely that the crop-growing regions of the United States will continue to escape the rising temperatures, Lobell said.

"The climate science is still unclear about why summers in the Corn Belt haven't been warming. But most explanations suggest that warming in the future is just as likely there as elsewhere in the world," Lobell said.

"In other words, farmers in the Corn Belt seem to have been lucky so far."

This is the first study to come up with a global estimate for the past 30 years of what has been happening, Lobell said.

To develop their estimates, the researchers used publicly available global data sets from the United Nations Food and Agriculture Organization and from the University of Delaware, University of Wisconsin, and McGill University.

The researchers also estimated the economic effects of the changes in crop yield using models of commodity markets.

"We found that since 1980, the effects of climate change on crop yields have caused an increase of approximately 20 percent in global market prices," said Wolfram Schlenker, an economist at Columbia University and a coauthor of the paper in Science.

He said if the beneficial effects of higher carbon dioxide levels on crop growth are factored into the calculation, the increase drops down to 5 percent.

"Five percent sounds small until you realize that at current prices world production of these four crops are together worth nearly $1 trillion per year," Schlenker said. "So a price increase of 5 percent implies roughly $50 billion per year more spent on food."

Rising commodity prices have so far benefited American farmers, Lobell and Schlenker said, because they haven't suffered the relative declines in crop yield that the rest of the world has been experiencing.

"It will be interesting to see what happens over the next decade in North America," Lobell said. "But to me the key message is not necessarily the specifics of each country. I think the real take-home message is that climate change is not just about the future, but that it is affecting agriculture now. Accordingly, efforts to adapt agriculture such as by developing more heat- and drought-tolerant crops will have big payoffs, even today. "

Justin Costa-Roberts, an undergraduate student at Stanford, is also a coauthor of the Science paper. David Lobell is a researcher in Stanford's Program on Food Security and the Environment, a joint program of Stanford's Woods Institute for the Environment and Freeman Spogli Institute for International Studies. Schlenker is an assistant professor at the School of International and Public Affairs and at the Department of Economics at Columbia.

The work was supported by a grant from the Rockefeller Foundation.

"Most of the people in the world are poor, so if we knew the economics of being poor, we would know much of the economics that really matters. Most of the world's poor people earn their living from agriculture, so if we knew the economics of agriculture, we would know much of the economics of being poor." - Theodore W. Schultz, accepting the Nobel Prize in Economics, December 8, 1979           

More than thirty years ago, Theodore W. Schultz won the Nobel Prize in Economics for his work on economic development and agriculture in developing countries. Last week, Cornell University Professor Christopher Barrett told Stanford students, faculty, and community members that Schultz's ideas suggest a powerful approach to breaking persistent cycles of poverty in modern rural Africa.

Barrett, a Professor of Applied Economics and Management and an expert in poverty and international development, visited the Stanford campus for a two-hour symposium entitled "Assisting the Escape from Persistent Ultra-Poverty in Rural Africa." He described the economics of poverty and agriculture in rural Africa as a series of downward spirals in environmental and human health.

The struggle to survive on insufficient resources, he explained, leads to disease and degradation that result in still deeper poverty. Escaping this cycle requires an influx of assets - a "lump of starting capital" in both private and public goods - that Barrett said the international community can provide.

"It takes money to make money," Barrett said. "Asset holdings, and their productivity through technology and markets, matter enormously."

When African farmers and pastoralists slip below a certain threshold of asset poverty, Barrett explained, they face negative feedbacks that set off a steep decline.

For example, a farmer who cultivates the same tiny plot of land year after year depletes soil nutrients to the point where even heavy fertilizer applications cannot revive the crop. Similarly, a pastoral family that begins with a small herd may become sedentary if they are unable to provide for the elderly and infirm while keeping their animals on the move. Stuck in one place, the herd exhausts local resources, and animals and humans alike suffer the health consequences of insufficient food and water.

A farmer who begins with plenty of land can sustain higher yields and invest surplus profits in education, health care, better equipment and still more land. But for the small farmer, incentives to invest in a better future are low, because the consequences of losing even a little income - an accelerated decline toward deeper poverty - are so severe.

Subsistence activity takes precedence, and when bad weather or disease strikes, the results are devastating. Limited access to credit, technology, and markets; weak government; and a harsh physical landscape make it still more difficult for rural Africans to invest in productive assets and recover from chance shocks.

These negative feedbacks and perverse incentives, Barrett said, make African poverty uniquely persistent.

While poor families in the developed world usually experience brief deprivation as a result of job loss or another isolated event, ultra-poor families in rural Africa have exhausted their land, livestock, and other productive assets. Without the means to restore natural and human capital, they may face a lifetime of poverty.

"In the US, poverty, while distressingly widespread, is a short-term phenomenon," Barrett noted. ""It is qualitatively and ethically different to talk about people who have very little hope of leaving poverty."

But Barrett said that the next generation of rural Africans has reason to be hopeful. While there is no one-size-fits-all approach, targeted investment could improve the outlook for many poor African nations. Barrett cited a generation of successful poverty relief efforts in Asia, where ultra-poverty rates in some countries have fallen from the high teens to less than five percent.

"East and Southeast Asia were at least as grim a generation ago as Africa is today," Barrett emphasized. "We know from the historical record that the world can move a lot of people out of poverty very quickly."

Citing Schultz's Nobel Prize acceptance speech, Barrett suggested that the international community focus first on reversing the cycles of decline that have pushed so many African farmers into meager subsistence agriculture.

Farm output, he said, universally impacts the rural poor. When output increases, poor farmers gain directly by selling their surplus. The extra supply also keeps local food prices low, benefiting the vast majority of rural Africans who consume more food than they produce.

Barrett described several possible "entry points" to stimulate agricultural productivity, including direct land and livestock grants, organized provision of rural education and health care, and renewed commitment to African crop research.

Private entrepreneurs, he said, are particularly well situated to invest in the technology and infrastructure needed to open rural markets, support soil and water conservation, and improve communication between buyers and sellers.

Barrett said that relief efforts should ultimately turn their attention to moving rural Africans out of agriculture. High rural population densities have compressed average farm sizes to a fraction of a hectare, he explained, making farming an unsustainable enterprise. More and more rural Africans are suffering the consequences of trying to do too much with too little.

"They find farming hard work," Barrett said, "and they'd like their kids to be able to find something else to do."

Barrett already sees a brighter future for those farmers and their children. "With governments and private investors already increasing their commitments to agriculture and rural development in Africa," he said, "I firmly believe we are in the early stages of being on the way."

This talk was the third in FSE's Global Food Policy and Food Security Symposium Series.