Governments must do more to diversify the types of crops grown throughout the world. If they don’t, climate change may jeopardize the global food supply, a leading agriculture researcher told a Stanford audience.

Cary Fowler, a senior advisor and former executive director of the Global Crop Diversity Trust, was a driving force behind the creation of the Svalbard Global Seed Vault in Norway. Commonly known as the “doomsday vault,” the repository of ancient and modern seeds from around the world ensures that future generations will have access to a wide enough range of crop traits to adapt global agriculture to a changing climate.

Dr. Cary Fowler in Svalbard, Norway, the home of the Svalbard Global Seed Vault.

During a May 6 talk sponsored by FSE as part of the center’s Food and Nutrition Policy Symposium, Fowler warned that increasingly high temperatures and water shortages interfere with the natural growing cycles of many crops and can even reduce the nutritional quality of some plants. Higher temperatures also give way to new pests, diseases, and soil microorganisms that threaten yields.

 “The biggest impacts from climate change will be in sub-Saharan Africa,” Fowler said, a region where many people already suffer serious poverty and hunger, and where crop yields lag behind the rest of the world. Fowler said that as climate pressure on agriculture intensifies, the world can expect to see an uptick in civil conflict, restrictive trade policies, and suffering among the world’s poorest people.

“Crops are going to be facing new combinations of conditions for which there is no historical experience,” said Fowler. “They will require new combinations of traits” that can only be developed by preserving genetic diversity and proactively breeding new varieties.

 “There are 1.3 billion people living on subsistence farms today,” said Dr. Cary Fowler to a Stanford audience on May 6. “How will they adapt to climate change without access to diversity?”

Fowler called for the U.S. and foreign governments to embrace their “inherited evolutionary responsibility” for preserving the huge diversity of crops grown by farmers throughout human history.

The United States is the ideal candidate to lead the world in using crop genetic diversity to adapt agriculture to climate challenges, he said. “The U.S. is well-positioned to research diversity, model future climate and assemble seed packages,” enlisting farmers in the U.S. and abroad in “another mass adaptation experiment” like the one American agriculture undertook in the 18^th and 19^th centuries.

 “I know that sounds like a wild and crazy idea,” Fowler said. “But I haven’t heard any alternatives to it. If we’re assuming we’re going to have development without diversity, that would really be a historically unprecedented experiment.”

 “If agriculture doesn’t adapt,” he added, “neither will we.”

A diverse history

In the late 1700s the United States food system lacked diversity and infrastructure. “Very few of the crops we grow now in the U.S. are native,” said Fowler. Early on, “it wasn’t always evident what crops from abroad would grow well in the U.S.”

The government soon set out to expand and diversify American agriculture. U.S. Navy ships collected seeds on overseas voyages, and U.S. diplomats brought back new crops from postings abroad. Government-sponsored expeditions sought out foreign plants with specific disease-resistant traits. The U.S. signed two dozen seed-exchange agreements with other countries, and lowered taxes on imported seeds to boost global crop exchange.

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“The United States amassed a much more diverse array of seeds and crops as a result,” said Fowler. One program introduced 600 new apple varieties, 700 new types of pears, and 353 new varieties of mangoes to American farmers.

But the United States did not simply collect new crops. It also invested in research to develop new varieties, including through plant breeding.

Genetic erosion

Research into plant breeding quickly yielded many of the modern varieties of crops we grow today in the United States.

“With plant breeding came the rise of modern varieties that had useful traits like disease resistance,” said Fowler. A small handful of new varieties quickly gained popularity with American farmers, who now had a choice about whether or not to save seeds and grow many varieties of a crop at once. Most farmers chose not to, instead relying on the same few mainstream varieties their neighbors were growing.

This shift has led to what Fowler described as the “genetic erosion” of agriculture, a trend that can only be reversed by reviving the tradition of seed saving and plant breeding on a global scale.

Seed banks

“I have probably been to more seed banks than any other person,” said Fowler. Seeds from most crops can survive hundreds or even thousands of years in storage, but most storage facilities lack the physical security to provide lasting safe haven. Many seed banks are poorly built, too warm or humid for long-term storage, and vulnerable to natural disasters. Other facilities suffer damaged during civil wars and uprisings.

Even if banks are physically secure, said Fowler, most simply do not operate on a large enough scale to protect global crop diversity. “Most crops in the world have between one and 10 total seed samples in storage, and most have no plant breeders working on them at all,” said Fowler.

The doomsday vault

In 2005 Fowler was chosen to lead an international coalition to build the Svalbard Global Seed Vault. The Norwegian government owns the facility, and it is also managed by the Global Crop Diversity Trust and the Nordic Genetic Resource Center. 

The vault is built into the side of a mountain in the far north of Norway, said Fowler, because the ideal temperature for storing seeds is minus 18 degrees Celsius.

Inside the frozen walls of the vault are shelves full of boxes holding duplicate seeds from smaller seed banks around the world. Foreign governments that contribute samples pay nothing for storage, and the seed packages are never opened by vault staff, said Fowler.

 “The vault now houses seeds from over 864,000 varieties of plants,” said Fowler, adding that not a single sample has ever been lost.

Seed storage boxes at the Svalbard Global Seed Vault.

The facility’s nickname, “the doomsday vault,” comes not only from its rugged physical location but from its capacity to withstand disasters – something its planners took great care to design. “We calculated how high the water would go if all ice in the world melted and we had the world’s largest ever tsunami,” said Fowler. “The vault is five stories above that.”

“Not a solution”

Fowler emphasized that no doomsday vault, no matter how secure its walls or how ample its seed collection, can solve the problem of crop genetic erosion. Building a vault “doesn’t mean that we as a society are getting serious about adapting agriculture to climate change,” Fowler said. Plant breeding and crop research programs focused on developing new climate-resilient varieties are just as crucial as saving seeds.

Although a few major staple crops like rice, wheat and corn are continually bred and improved in research labs around the world, most crops are largely ignored by researchers. For example, there are only six breeders of yams worldwide.

“Why conserve it if you’re not going to use it?” Fowler asked. “We are acting like crops are going to adapt by themselves, and we are assuming all but a handful of crops are unimportant.”

Quoting Charles Darwin, Fowler added that “it is not the strongest of the species that survives, nor the most intelligent, but the one most responsive to change.”

Full video and audio recordings of Dr. Fowler's May 6 lecture, and his interview with FSE director Roz Naylor, are available here. 

FSE deputy director David Lobell has been named the William Wrigley Senior Fellow at the Stanford Woods Institute for the Environment and the Freeman Spogli Institute for International Studies (FSI). Lobell is also an Associate Professor in Earth System Science. 

Lobell's research focuses on identifying opportunities to raise crop yields in major agricultural regions, with a particular emphasis on adaptation to climate change. His current projects span Africa, South Asia, Mexico, and the United States, and involve a range of tools including remote sensing, GIS, and crop and climate models.

"David Lobell's research on climate change and food security is truly global in scope, but his work also crosses academic borders," said FSI director Mike McFaul. "David's appointment as William Wrigley Senior Fellow recognizes his ability to connect the most pressing challenges in international  development with critical questions of environmental sustainability, in a way that generates real solutions on both fronts."

The William Wrigley Senior Fellowship is supported by Mrs. Julie Ann Wrigley, AB '71 (Anthropology) and Ms. Alison Wrigley Rusack, AB '80 (Communication).

"The Wrigley fellowship recognizes the important contributions of our faculty to ensuring a sustainable world and is one family’s remarkable legacy to reshape the future of the environment on which we all depend," said Perry L. McCarty Director Barton "Buzz" Thompson, who co-leads the Stanford Woods Institute with Perry L. McCarty Director Jeffrey Koseff.  "Both David and the first holder of the fellowship, Roz Naylor, are leaders in the effort to provide food security to the planet's growing population, perhaps the most critical challenge the world faces."

"David's work already transcends disciplines and departments through his work with the Center on Food Security and the Environment, a synergistic partnership between Woods and the Freeman Spogli Institute," Koseff added. "The Wrigley fellowship provides important support for this type of collaborative, cross-cutting research at Stanford."

Lobell was a Senior Research Scholar at the Center on Food Security and the Environment from 2008-2009 and a Lawrence Post-doctoral Fellow at Lawrence Livermore National Laboratory from 2005-2007. He received a PhD in Geological and Environmental Sciences from Stanford University in 2005, and a Sc.B. in Applied Mathematics, Magna Cum Laude from Brown University in 2000.

FSE director Roz Naylor has been selected to deliver the 6th annual Ned Ames Honorary Lecture at the Cary Institute of Ecosystem Studies in Millbrook, NY on Friday, April 24. Her lecture on "Feeding the World in the 21st Century," is free and open to the public, and a video recording of the event will be available on the Cary Institute's website shortly after the talk.

A chance course at Stanford and a study-abroad trip to Nepal changed the trajectory of Marshall Burke's career, leading him to a human-focused approach studying climate change. His latest work deals with the link between rising temperatures and human violence. 

I pray thee, good Mercutio, let's retire:
The day is hot, the Capulets abroad,
And, if we meet, we shall not scape a brawl;
For now, these hot days, is the mad blood stirring.

That a connection exists between hot temperatures and flaring tempers is an old observation. In William Shakespeare's Romeo and Juliet, Benvolio begs his friend Mercutio to take shelter from the heat, lest it lead to a street fight with a member of the Capulet family.

“Even in Shakespeare’s time, it was recognized that people are more likely to lose their tempers when it’s hot outside,” said Marshall Burke, an assistant professor in the department of Environmental Earth System Science and a fellow at the Freeman Spogli Institute for International Studies and its Center on Food Security and the Environment (FSE).

The link between temperature and violence has come under increased scientific scrutiny in recent years because of climate change. In 2013, Burke made waves in scientific circles and in the popular press when he and Solomon Hsiang, now an assistant professor of public policy at the University of California, Berkeley, performed a meta-analysis of over 50 scientific studies and found that climate change is increasing various kinds of human conflict–everything from individual-level violence, such as assault and robbery, all the way up to group-level conflicts such as civil wars and skirmishes between nations.

"What we see is that over and over, no matter where you look, you see more conflict and more violence when temperatures are hotter than average," Burke said.

Climate change and violence

Prior to Burke and Hsiang's study, several papers had suggested possible links between climate change and violence, but the research was scattered across disciplines and the results often conflicted with one another. The pair sought to cut through the morass by putting all of the papers on an equal empirical footing. "We got a hold of all of the datasets that we could and reanalyzed them in exactly the same way," Burke said. "When we did that, what came through was a very strong and consistent relationship between hotter-than-average temperatures and increases in all these types of conflicts."

We are learning about ourselves and we can shape our trajectories in ways that we wouldn't have been able to if we didn't have this information. To me, that's very hopeful.

Burke says he was surprised by the how strong and consistent the signal was. For example, of the 27 studies from the modern era that looked directly at the relationship between temperature and conflict, all 27 of them found a positive relationship. "The chance of that happening at random or by chance is less than 1 in 10 million,” Burke said.

Burke finds it fascinating that a relationship between temperature and violence should exist at all. Economists have speculated that temperature affects human conflict through changes in economic productivity. The idea is that by increasing the likelihood of droughts in certain parts of the world, climate change is reducing crop productivity and driving people already in dire straits to take desperate measures such as joining rebellions. "In places like Sub-Saharan Africa, you don't need that many people to start a civil war," Burke said.

Human physiology almost certainly plays a key role as well. Studies show that people just behave badly when it’s hot. "Experiments have shown that whether it’s a cooperation task, or one that requires concentration, people just do poorly if it's hotter in the room," Burke said. "We're just wired to do better at some temperatures than at others."

Because global warming is unlikely to abate anytime soon, even if mitigation policies are enacted, understanding why hotter temperatures brings out the worst in humans is crucial for determining solutions to curb violent tendencies as global temperatures rise, Burke said. "If the root cause is agricultural, we might want to invest in things that boost crop yields or that reduces crop sensitivity to really hot temperatures," he added. "If it’s something to do with human physiology, the problem becomes much more difficult. You might say, well we could just invest in air conditioning, but even in the U.S. where we have lots of air conditioning, you still see this strong relationship."

Burke's own background is in economics, but he plans to team up with medical scientists to explore just how temperature affects human physiology. "That's what's exciting about being at Stanford, and one of the main reasons I accepted a position here," Burke said. "It's really easy to cross disciplines here and make connections in other fields."

People-focused

Being interdisciplinary comes naturally to Burke. His undergraduate education at Stanford University straddled the social sciences and the natural sciences. Initially an Earth Systems major, Burke later switched to International Relations after taking a course called "The World Food Economy" that was co-taught by Roz Naylor, the William Wrigley Professor in Earth Science. "I took that class and it literally changed my trajectory. I knew that this kind of human-focused research was what I wanted to do," Burke said.

Burke was also deeply affected by time he spent living in Nepal with poor farming families during his junior year as part of a semester abroad program. "It was my first real confrontation with deep and grinding rural poverty," he said. "That experience made me want to understand what's going on and think about the kind of research I needed to do if I wanted to help."

After graduating, Burke worked as a research assistant for Naylor and Walter Falcon, now the deputy director of FSE, where he helped investigate the impacts of agricultural systems on the environment and ways to use agriculture to reduce poverty around the world.  "Since most of the poor people in the world continue to work in agriculture, our idea was that if we could improve how much was produced on small farms, it would have a big impact on global poverty," Burke said.

Burke also credits Naylor and Falcon with making him think more deeply about the connections between climate change and agriculture. Later, while earning his PhD in agricultural and resource economics at the University of California, Berkeley, Burke's research interests broadened further to look at how climate change effects on agriculture might in turn impact the economic health and social cohesion of a country. "For me, it was a natural to begin by thinking about climate change impacts on agriculture and then following that line of reasoning to investigate other knock-on effects," Burke said.

A silver lining

When Burke is not at Stanford, he can often be found taking photographs or hiking and rock climbing with his family. His office is decorated with photos he’s taken of Death Valley, Yosemite Valley, and Nepal, where he returned with his wife for their honeymoon.

Burke credits the time he spent outdoors as a child for his lifelong interest in environmental issues, and it's a tradition that he continues with his two young girls. "We have two-year-old twins, and my wife and I have little harnesses that we use to take them rock climbing. So far they're more interested in swinging around on the rope than in actually climbing, but it's fun," he said.

Burke says the time he spends in the mountains and deserts are not just for his own mental well being and happiness. “It’s a constant reminder about the things I work on and what’s at stake,” he said.

Marshall Burke and his wife rocking climbing with their two-year-old daughter at Joshua Tree.

He acknowledged that many of the predictions from climate change impact studies are frightening and depressing, but he thinks there is a silver lining that often gets overlooked. "We live in a unique moment in history when we have a wealth of tools and data that can help us understand how human societies and the environment are coupled," Burke said.

"We are learning about ourselves and we can shape our trajectories in ways that we wouldn't have been able to if we didn't have this information. To me, that's very hopeful."

Burke is also a fellow at the Center on Food Security and the Environment (FSE) and a fellow at the Freeman Spogli Institute for International Studies.

Ker Than is associate director of communications for the School of Earth, Energy & Environmental Sciences. Contact: 650-723-9820, kerthan@stanford.edu

A new study by Center on Food Security and the Environment researchers finds that smallholder irrigation systems - those in which water access (via pump or human power), distribution (furrow, watering can, sprinkler, drip lines, etc.), and use all occur at or near the same location - have great potential to reduce hunger, raise incomes and improve development prospects in an area of the world greatly in need of these advancements. Financing is crucial, as even the cheapest pumps can be prohibitively expensive otherwise.

These systems have the potential to use water more productively, improve nutritional outcomes and rural development, and narrow the income disparities that permit widespread hunger to persist despite economic advancement. Only 4 percent of agricultural land in sub-Saharan Africa is currently irrigated.

"Success stories can be found where distributed systems are used in a cooperative setting, permitting the sharing of knowledge, risk, credit and marketing as we've seen in our solar market garden project in Benin," said Jennifer Burney, lead author of the study published in the Proceedings of the National Academy of Sciences.

Moving forward development communities and sub-Saharan African governments need a better understanding of present water resources and how they will be affected by climate change.

"Farmers need access to financial services—credit and insurance—appropriate for a range of production systems," said co-author and Stanford Woods Institute Senior Fellow Rosamond Naylor. "Investments should start at a smaller scale, with thorough project evaluation, before scaling up."

FSE continues to contribute to these evaluations and added eight new villages to our project in Benin last year.