Food Security
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The economic costs of Indonesia’s 2015 forest fires are estimated to exceed US $16 billion, with more than 100,000 premature deaths. On several days the fires emitted more carbon dioxide than the entire United States economy. Here, we combine detailed geospatial data on fire and local climatic conditions with rich administrative data to assess the underlying causes of Indonesia’s forest fires at district and village scales. We find that El Niño events explain most of the year-on-year variation in fire. The creation of new districts increases fire and exacerbates the El Niño impacts on fire. We also find that regional economic growth has gone hand-in-hand with the use of fire in rural districts. We proceed with a 30,000-village case study of the 2015 fire season on Sumatra and Kalimantan and ask which villages, for a given level of spatial fire risk, are more likely to have fire. Villages more likely to burn tend to be more remote, to be considerably less developed, and to have a history of using fire for agriculture. Although central and district level policies and regional economic development have generally contributed to voracious environmental degradation, the close link between poverty and fire at the village level suggests that the current policy push for village development might offer opportunities to reverse this trend.


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Journal Articles
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World Development Journal
Authors
Rosamond L. Naylor
Walter P. Falcon
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As the global population and people’s incomes rise, the demand for ocean-derived food will continue to grow. At the same time, hunger and malnutrition continues to be a challenge in many countries, particularly in rural or developing areas. Looking to the ocean as a source of protein produced using low-carbon methodologies will be critical for food security, nutrition and economic stability, especially in coastal countries where hunger and malnutrition are a challenge. Yet these advances in ocean production can only be achieved with a concurrent focus on addressing threats to ocean health, such as climate change and overfishing.

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Conference Memos
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High Level Panel for a Sustainable Ocean Economy
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Rosamond L. Naylor
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Understanding the determinants of agricultural productivity requires accurate measurement of crop output and yield. In smallholder production systems across low- and middle-income countries, crop yields have traditionally been assessed based on farmer-reported production and land areas in household/farm surveys, occasionally by objective crop cuts for a sub-section of a farmer’s plot, and rarely using full-plot harvests. In parallel, satellite data continue to improve in terms of spatial, temporal, and spectral resolution needed to discern performance on smallholder plots. This study evaluates ground- and satellite-based approaches to estimating crop yields and yield responsiveness to inputs, using data on maize from Eastern Uganda. Using unique, simultaneous ground data on yields based on farmer reporting, sub-plot crop cutting, and full-plot harvests across hundreds of smallholder plots, we document large discrepancies among the ground-based measures, particularly among yields based on farmer-reporting versus sub-plot or full-plot crop cutting. Compared to yield measures based on either farmer-reporting or sub-plot crop cutting, satellite-based yield measures explain as much or more variation in yields based on (gold-standard) full-plot crop cuts. Further, estimates of the association between maize yield and various production factors (e.g., fertilizer, soil quality) are similar across crop cut- and satellite-based yield measures, with the use of the latter at times leading to more significant results due to larger sample sizes. Overall, the results suggest a substantial role for satellite-based yield estimation in measuring and understanding agricultural productivity in the developing world.

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American Journal of Agricultural Economics
Authors
David Lobell
Marshall Burke
George Azzari, Sydney Gourlay, Zhenong Jin, Talip Kilic, Siobhan Murray
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Feeding a growing population while reducing negative environmental impacts is one of the greatest challenges of the coming decades. We show that microsatellite data can be used to detect the impact of sustainable intensification interventions at large scales and to target the fields that would benefit the most, thereby doubling yield gains. Our work reveals that satellite data provide a scalable approach to sustainably increase food production.

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Nature Sustainability
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Meha Jain, Balwinder-Singh, Preeti Rao, Amit K. Srivastava, Shishpal Poonia, Jennifer Blesh, George Azzari, Andrew J. McDonald
David Lobell
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Fighting to End Hunger at Home & Abroad:  Ambassador Ertharin Cousin shares her journey & lessons learned

A Conversation in Global Health with Ertharin Cousin

FSI Payne Distinguished Lecturer | Former Executive Director of the World Food Programme | TIME's 100 Most Influential People

RSVP for conversation & lunch: www.tinyurl.com/CIGHErtharinCousin (please arrive at 11:45 am for lunch)

Professor Ertharin Cousin has been fighting to end global hunger for decades. As executive director of the World Food Programme from 2012 until 2017, she led the world’s largest humanitarian organization with 14,000 staff serving 80 million vulnerable people across 75 countries. As the US ambassador to the UN Agencies for Food and Agriculture, she served as the US representative for all food, agriculture, and nutrition related issues.

Prior to her global work, Cousin lead the domestic fight to end hunger. As chief operating officer at America’s Second Harvest (now Feeding America), she oversaw operations for a confederation of 200 food banks across America that served more than 50,000,000 meals per year.

Stanford School of Medicine Senior Communications Strategist Paul Costello will interview Professor Cousin about her experiences, unique pathway, and the way forward for ending the global hunger crisis.

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Li Ka Shing Room 320 

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Massive changes in the global food sector over the next few decades – driven by climate change and other environmental stresses, growing population and income, advances in technology, and shifts in policies and trade patterns – will have profound implications for the oceans. Roz Naylor, Senior Fellow and Founding Director of Stanford’s Center on Food Security and the Environment,  will discuss the interplay between terrestrial and marine food systems, highlighting the rising role of aquaculture in helping to meet the nutritional demands of 9-10 billion people by 2050. As a platform for her talk, she will introduce a new research initiative at Stanford on “Oceans and the Future of Food”, co-led by the Center for Oceans Solutions (COS) and the Center on Food Security and the Environment (FSE).

Free Admission is by reservation only. Please call 831-655-6200 between 8:30AM – 5:00PM, Mon-Fri, or RSVP at the Friends of Hopkins web page.

Contact:
Amanda Whitmire
831-655-6200
thalassa@stanford.edu

Boat Works Lecture Hall, Hopkins Marine Station

Lectures
Authors
Taylor Kubota
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As more of the greenhouse gas carbon dioxide enters the atmosphere, leading to climate change, crops might carry fewer nutrients, like zinc and iron. Stanford researchers explored this trend and regions most likely to be hurt by it.

As the climate changes, where plants grow best is predicted to shift. Crops that once thrived as a staple in one region may no longer be plentiful enough to feed a community that formerly depended on it. Beyond where plants grow, there’s also the issue of how they grow. Evidence suggests that plants grown in the presence of high carbon dioxide levels aren’t as nutritious.

“Zinc is critical for the immune system and zinc deficiency makes pneumonia, diarrheal illness, malaria more difficult for the body to combat,” said Eran Bendavid, associate professor of medicine. “Iron deficiency has all sorts of manifestations, from lethargy and feeling ill to broader effects, like worse performance in school.”

David Lobell, professor of Earth system science in the School of Earth, Energy & Environmental Sciences, has been studying the relationship between climate change and crops. He was drawn to the relationship between C02 and crop nutrition because his work pairs findings from scientific models with concrete observations.

“Any time you’re looking at data, you need observations that correspond to the conditions you’re trying to understand. But you have to be creative to find data sets that allow for this kind of validation,” Lobell said.

Years of life lost due to less nutritious crops

The researchers estimated how many additional years of healthy life would be lost from 2015 to 2050 due to carbon dioxide-related declines in zinc and iron in crops. This data represents the base case scenario, where carbon dioxide levels climb relatively unabetted. These predictions start at 2015 but health disparities between the regions already existed: at that time, the African Region was losing approximately four times as many healthy years due to these nutrient insufficiencies as the European Region. (Image credit: Yvonne Tang)

Last year, Lobell, Bendavid and Stanford collaborators including management science and engineering graduate student Christopher Weyant, published a paper in which they projected how crop nutrition – zinc and iron levels – will respond to climate change in the coming decades and what that might mean for human health. They looked at two different scenarios, one a base case scenario in which carbon dioxide levels climb relatively unabetted, resulting in a nearly 40 percent increase in carbon dioxide concentrations by 2050. In the other, the group assumed global temperatures would remain within 2 degrees Celsius of pre-industrial levels, as proposed by the Paris Agreement.

For each scenario, they calculated how many years of healthy life people around the world would lose due to illness, disability or death as a result of less iron and zinc in their diet. In the base case scenario, they also explored how different health care interventions, including zinc or iron supplementation, and disease control programs for pneumonia, diarrhea and malaria could help.

Reductions in years of life lost through different interventions

The researchers estimated total years of healthy life lost from 2015 to 2050 due to carbon-dioxide-related zinc and iron deficiencies, with different interventions. The researchers’ predictions showed that keeping to the Paris Agreement goals and reducing greenhouse gas emissions results in far better health outcomes than other solutions, such as supplementing nutrients. (Image credit: Yvonne Tang)

They projected that, by far, the most effective way to reduce the consequences of this carbon dioxide-induced disease burden was to limit the amount of carbon dioxide in the atmosphere. In their model, sticking to Paris Agreement goals avoided 48.2 percent of the healthy years lost to carbon dioxide-induced nutritional diseases. In contrast, providing health care interventions only reduced years of healthy life lost by 26.6 percent.

As with other research on the impact of climate change, these nutritional deficiencies are more likely to affect the poorest people first and most severely. But Lobell cautions against assuming it is a problem happening somewhere else.

“Even in a world that is getting more and more food secure, malnutrition would be among the biggest – if not the biggest – health effects of climate change,” Lobell said.

Lobell is now studying what large and small farms are currently doing to combat climate change and the effectiveness of those efforts. One aspect of this work is his lab’s analysis of high-resolution images from satellites to estimate crop yields from space.

Additional co-authors of the paper are Margaret Brandeau and Marshall Burke of Stanford. Senior author was Sanjay Basu of Stanford. Bendavid is also a member of the Maternal & Child Health Research Institute (MCHRI) and an affiliate of the Stanford Woods Institute for the Environment. Lobell is also a senior fellow at the Freeman Spogli Institute for International Studies, at the Stanford Woods Institute for the Environment and at the Stanford Institute for Economic Policy Research. He is also an affiliate of the Precourt Institute for Energy.

The way we treat the planet has direct consequences on human health. This series of stories explores some of those consequences and what we can do to lessen the risks.

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Accurate prediction of crop yields in developing countries in advance of harvest time is central to preventing famine, improving food security, and sustainable development of agriculture. Existing techniques are expensive and difficult to scale as they require locally collected survey data. Approaches utilizing remotely sensed data, such as satellite imagery, potentially provide a cheap, equally effective alternative. Our work shows promising results in predicting soybean crop yields in Argentina using deep learning techniques. We also achieve satisfactory results with a transfer learning approach to predict Brazil soybean harvests with a smaller amount of data. The motivation for transfer learning is that the success of deep learning models is largely dependent on abundant ground truth training data. Successful crop yield prediction with deep learning in regions with little training data relies on the ability to fine-tune pre-trained models.

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COMPASS '18 Proceedings of the 1st ACM SIGCAS Conference on Computing and Sustainable Societies
Authors
Anna Wang
Caelin Tran
Nikhil Desai
David Lobell
Stefano Ermon
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Crop type mapping at the field level is necessary for a variety of applications in agricultural monitoring and food security. As remote sensing imagery continues to increase in spatial and temporal resolution, it is becoming an increasingly powerful raw input from which to create crop type maps. Still, automated crop type mapping remains constrained by a lack of field-level crop labels for training supervised classification models. In this study, we explore the use of random forests transferred across geographic distance and time and unsupervised methods in conjunction with aggregate crop statistics for crop type mapping in the US Midwest, where we simulated the label-poor setting by depriving the models of labels in various states and years. We validated our methodology using available 30 m spatial resolution crop type labels from the US Department of Agriculture's Cropland Data Layer (CDL). Using Google Earth Engine, we computed Fourier transforms (or harmonic regressions) on the time series of Landsat Surface Reflectance and derived vegetation indices, and extracted the coefficients as features for machine learning models. We found that random forests trained on regions and years similar in growing degree days (GDD) transfer to the target region with accuracies consistently exceeding 80%. Accuracies decrease as differences in GDD expand. Unsupervised Gaussian mixture models (GMM) with class labels derived using county-level crop statistics classify crops less consistently but require no field-level labels for training. GMM achieves over 85% accuracy in states with low crop diversity (Illinois, Iowa, Indiana, Nebraska), but performs sometimes no better than random when high crop diversity interferes with clustering (North Dakota, South Dakota, Wisconsin, Michigan). Under the appropriate conditions, these methods offer options for field-resolution crop type mapping in regions around the world with few or no ground labels.

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Remote Sensing of Environment
Authors
Sherrie Wang
George Azzari
David Lobell
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Blogs
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Twelve-year-old Lena is growing up poor and malnourished on Chicago’s West Side. She buys Blue Juice and Hot Chips from the corner store on her way to school. She and her classmates can afford the flavoured sugar water and salty starch, but this cheap “food” that fills up her stomach provides no nutritional value. 

Lena is one of over 20 million Americans living in food deserts, places without access to a full-service grocery store within two miles. Yet while Lena buys her Hot Chips, an affluent family nearby uses an online retail platform to order their weekly delivery of fresh, nutritious food – at prices that Lena and her family can’t afford. Despite a surge of technology innovations in food retail, Lena and her family represent a growing number of underserved customers around the world.

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