Stephen Schneider, the Lane Professor for Interdisciplinary Environmental  Studies and former co-director, with Walter Falcon, of FSI's Center for Environmental Science and Policy -- now part of the Woods Institute for the Environment -- has died.  Schneider spent decades studying and writing about the forces influencing climate change, pressing the case for action to curb emission of greenhouse gases.  He was a highly respected member of the Intergovernmental Panel on Climate Change from its inception through the last days of his life, explaining the scientific evidence to the lay public in lively and easily understood terms.  He will be greatly missed.

The hardest evidence for a link so far comes from a team led by Marshall Burke of the University of California and FSE Research Associate, and co-authored with FSE Fellow David Lobell. They studied African wars from 1980 to 2002 and found that rising temperatures are indeed associated with crop failure, economic decline and a sharp rise in the likelihood of war. It predicted a “50% increase” in the chance of civil war in Africa by 2030.

Advances in high-yield agriculture over the latter part of the 20th century have prevented massive amounts of greenhouse gases from entering the atmosphere - the equivalent of 590 billion metric tons of carbon dioxide - according to a new study led by two Stanford Earth scientists.

The yield improvements reduced the need to convert forests to farmland, a process that typically involves burning of trees and other plants, which generates carbon dioxide and other greenhouse gases.

The researchers estimate that if not for increased yields, additional greenhouse gas emissions from clearing land for farming would have been equal to as much as a third of the world's total output of greenhouse gases since the dawn of the Industrial Revolution in 1850.

The researchers also calculated that for every dollar spent on agricultural research and development since 1961, emissions of the three principal greenhouse gases - methane, nitrous oxide and carbon dioxide - were reduced by the equivalent of about a quarter of a ton of carbon dioxide - a high rate of financial return compared to other approaches to reducing the gases.

"Our results dispel the notion that modern intensive agriculture is inherently worse for the environment than a more 'old-fashioned' way of doing things," said Jennifer Burney, lead author of a paper describing the study that will be published online by the Proceedings of the National Academy of Sciences.

Adding up the impact

The researchers calculated emissions of carbon dioxide, methane and nitrous oxide, converting the amounts of the latter two gases into the quantities of carbon dioxide that would have an equivalent impact on the atmosphere, to facilitate comparison of total greenhouse gas outputs.

Burney, a postdoctoral researcher with the Program on Food Security and the Environment at Stanford, said agriculture currently accounts for about 12 percent of human-caused greenhouse gas emissions. Although greenhouse gas emissions from the production and use of fertilizer have increased with agricultural intensification, those emissions are far outstripped by the emissions that would have been generated in converting additional forest and grassland to farmland.

"Every time forest or shrub land is cleared for farming, the carbon that was tied up in the biomass is released and rapidly makes its way into the atmosphere - usually by being burned," she said. "Yield intensification has lessened the pressure to clear land and reduced emissions by up to 13 billion tons of carbon dioxide a year."

"When we look at the costs of the research and development that went into these improvements, we find that funding agricultural research ranks among the cheapest ways to prevent greenhouse gas emissions," said Steven Davis, a co-author of the paper and a postdoctoral researcher at the Carnegie Institution at Stanford.

To evaluate the impact of yield intensification on climate change, the researchers compared actual agricultural production between 1961 and 2005 with hypothetical scenarios in which the world's increasing food needs were met by expanding the amount of farmland rather than by the boost in yields produced by the Green Revolution.

"Even without higher yields, population and food demand would likely have climbed to levels close to what they are today," said David Lobell, also a coauthor and assistant professor of environmental Earth system science at Stanford.

"Lower yields per acre would likely have meant more starvation and death, but the population would still have increased because of much higher birth rates," he said. "People tend to have more children when survival of those children is less certain."

Avoiding the need for more farmland

The researchers found that without the advances in high-yield agriculture, several billion additional acres of cropland would have been needed.

Comparing emissions in the theoretical scenarios with real-world emissions from 1961 to 2005, the researchers estimated that the actual improvements in crop yields probably kept greenhouse gas emissions equivalent to at least 317 billion tons of carbon dioxide out of the atmosphere, and perhaps as much as 590 billion tons.

Without the emission reductions from yield improvements, the total amount of greenhouse gas pumped into the atmosphere over the preceding 155 years would have been between 18 and 34 percent greater than it has been, they said.

To calculate how much money was spent on research for each ton of avoided emissions, the researchers calculated the total amount of agricultural research funding related to yield improvements since 1961 through 2005. That produced a price between approximately $4 and $7.50 for each ton of carbon dioxide that was not emitted.

"The size and cost-effectiveness of this carbon reduction is striking when compared with proposed mitigation options in other sectors," said Lobell. "For example, strategies proposed to reduce emissions related to construction would cut emissions by a little less than half the amount that we estimate has been achieved by yield improvements and would cost close to $20 per ton."

The authors also note that raising yields alone won't guarantee lower emissions from land use change.

"It has been shown in several contexts that yield gains alone do not necessarily stop expansion of cropland," Lobell said. "That suggests that intensification must be coupled with conservation and development efforts.

"In certain cases, when yields go up in an area, it increases the profitability of farming there and gives people more incentive to expand their farm. But in general, high yields keep prices low, which reduces the incentive to expand."

The researchers concluded that improvement of crop yields should be prominent among a portfolio of strategies to reduce global greenhouse gases emissions.

"The striking thing is that all of these climate benefits were not the explicit intention of historical investments in agriculture. This was simply a side benefit of efforts to feed the world," Burney noted. "If climate policy intentionally rewarded these kinds of efforts, that could make an even bigger difference. The question going forward is how climate policy might be designed to achieve that."

David Lobell is a Center Fellow at the Freeman Spogli Institute for International Studies and at the Woods Institute for the Environment. The Program on Food Security and the Environment is a joint project of the Woods Institute and the Freeman Spogli Institute. The Precourt Institute for Energy and FSE provided funding for Jennifer Burney's research on agriculture and energy.

When Susan Rice graduated from Stanford in 1986, the Soviet Union was a formidable foe, China barely registered on the global economic scene and the first computer laptops – weighing in at 12 pounds each – were just hitting the market.

And if someone had told her that she'd serve in the Cabinet of the country's first black president as ambassador to the United Nations, "I would've asked them what they were smoking."

But in her remarks delivered during Stanford University's 119th Commencement on Sunday, Rice put the advances of the past 24 years in perspective. She called the fight against global poverty "not only one of the great moral challenges of all time, but also one of the great national security challenges of our time."

"The planet is still divided by fundamental inequalities," she said. "Some of us live in peace, freedom and comfort while billions are condemned to conflict, poverty and repression. These massive disparities erode our common security and corrode our common humanity."

While she did not discuss any specifics of her role as the country's ambassador to the United Nations or the organization's recent move to impose a fourth round of sanctions on Iran, Rice did talk about the link between poverty and security.

"When a country is wracked by war or weakened by want, its people suffer first. But poor and fragile states can incubate threats that spread far beyond borders – terrorism, pandemic disease, nuclear proliferation, criminal networks, climate change, genocide and more. In our interconnected age, a threat to development anywhere is a threat to security everywhere."
-Ambassador Susan Rice

Rice's address marked a very public return to Stanford. She graduated with a bachelor's in history from the university as a junior Phi Beta Kappa and Truman Scholar in 1986.

She was confirmed as ambassador to the United Nations in 2009 after being nominated by President Obama. It was a job that followed her role as Obama's senior adviser for national security affairs during his presidential campaign in 2007 and 2008. Before that, she served as the country's assistant secretary of state for African affairs and as a special assistant to President Clinton. She was also a senior director for African affairs at the National Security Council.

During a trip to a displaced persons camp in war-torn Angola in 1995, Rice saw firsthand the global poverty she talked about on Sunday. Of all the people she saw in the camp, she said one of her most striking memories is the smile she received from a malnourished little boy when she gave him her baseball cap.

But she's haunted by thoughts of what may have happened to him.

"I had to leave that camp," she said. "And when I did, I left that little boy in hell. I like to think, and I sure hope, that kid is OK. But he could well have become one of the 9  million children under the age of 5 who die each year from preventable and treatable afflictions."

And that boy, she said, should be a symbol to Stanford's graduates of the challenges that face them and the good they can do in the world.

"That little boy's future is tied to ours," she said. "Our security is ultimately linked to his well-being. So we must shape the world he deserves."

Rice's weighty remarks still left room for graduation levity. And the student procession – known as the Wacky Walk – showcased much of it.

The graduates hit the field of Stanford Stadium with balloons and signs thanking mom and dad. They were dressed as Egyptian kings and Vikings, wizards and butterflies. Some wore bathing suits and flowing togas. Others covered up with costumes paying homage to the pop culture past of Pac-Man, as well as more timeless pursuits like dominoes and poker.

It was a final blast of carefree fun for college students about to contend with an uncertain job market.

"We have everything we need on campus," said Tyler Porras, a graduating biology major who took to the field with a bolo tie and black cowboy hat. "Now it's off to the real world where you need to find a job."

The ceremony marked the award of 1,722 bachelor's degrees, 2,100 master's degrees and 980 doctoral degrees.

Departmental honors were awarded to 365 seniors, and 272 graduated with university distinction. Another 74 graduated with multiple majors and 33 received dual bachelor's degrees. There were 110 graduates receiving both bachelor's and master's degrees.

Among international students, there were 102 undergraduates from 45 countries other than the United States, and 955 graduate students from 75 foreign countries.

"As you leave Stanford, I hope you carry a deep appreciation of the values and traditions that are everlasting, as well as a willingness to be bold and to approach challenges with a fresh perspective," Stanford President John Hennessy told the graduates.

The day also gave parents a time to beam and brag.

"These kids have the potential to contribute so much to the world," said Tim Roake, whose daughter, Caitlin Roake, is graduating as a biology major and is planning to join the Peace Corps.

Roake and his wife, Kathleen Gutierrez, had front-row seats in the stadium bleachers next to Dave and Lori Gaskin. Their son, Greg, has been dating Caitlin Roake since their freshman year.

"The last four years for Greg have been such an enriching experience from an academic perspective but also on a personal level," Lori Gaskin said. "I attribute that not only to the university but the wonderful people he's met and the relationships he's made."