The Center on Food Security and the Environment is a joint effort of the Freeman Spogli Institute for International Studies and the Stanford Woods Institute for the Environment.
A team led by FSE fellow David Lobell has found a valuable, untapped resource in historical data from crop yield trials conducted across sub-Saharan Africa. Combined with weather records, they show that yield losses would occur across 65 percent of maize-growing areas from a temperature rise of a single degree Celsius, even with sufficient water.
Despite recent high-level statements suggesting that climate change could worsen the risk of civil conflict, until now we had little quantitative evidence linking the two. Unfortunately, our study finds that climate change could increase the risk of African civil war by over 50 percent in 2030 relative to 1990, with huge potential costs to human livelihoods. - David Lobell
Development of new crop varieties that are more heat and drought tolerant will be critical for successful adaptation to a warmer world. A recent 3 day meeting of international climate and crop experts at Stanford University focused on specific needs and promising approaches for improving crops. A meeting synopsis and recommended priorities can be found in a summary report, Climate Extremes and Crop Adaptation.
This study uses regression analysis to evaluate the relationships among sea surface temperature anomalies (SSTA) averaged over the Niño-3.4 region (5°N-5°S, 120°-170°W), rainfall, and rice production, area harvested, and yield in Luzon, the large island on which most Philippine rice is grown. Previous research on Philippine rice production and El Niño-Southern Oscillation (ENSO) has found negative associations between El Niño events and rice yields in rainfed systems. This analysis goes further and shows that both irrigated and rainfed ecosystems are impacted. It also compares impacts on area harvested and yield. Variations in average July-September Niño-3.4 SSTAs explain approximately 29% of the interannual variations in the deviations of total January-June (dry season) rice production from a polynomial trend for 1970-2005. In contrast, no impact was found on July-December production in either year t or t + 1. The impact of ENSO on dry-season rice production in Luzon appears to be primarily due to changes in area harvested rather than yield. Production declines for rainfed ecosystems are relatively larger than for irrigated ecosystems: a 1°C increase in average July-September Niño-3.4 SSTA is associated with a 3.7% decrease in irrigated dry-season production but with a 13.7% decline in rainfed dry-season production.
This study investigates the skill of linear methods for downscaling provincial-scale precipitation over Indonesia from fields that describe the large-scale circulation and hydrological cycle. The study is motivated by the strong link between large-scale variations in the monsoon and the El Nino - Southern Oscillation (ENSO) phenomenon and regional precipitation, and the subsequent impact of regional precipitation on rice production in Indonesia. Three different downscaling methods are tested across five different combinations of large-scale predictor fields, and two different estimates of regional precipitation for Indonesia.
Downscaling techniques are most skillful over the southern islands (Java and Bali) during the monsoon onset or transition season (Sep.-Dec.). The methods are moderately skillful in the southern islands during the dry season (May-Aug.), and exhibit poor skill during the wet season (Jan.-Apr.). In northern Sumatra downscaling methods are most skillful during Jan.-Apr. with little skill at other times of the year. There is little difference between the three different linear methods used to downscale precipitation over Indonesia. Additional analysis indicates that downscaling methods that are trained on the annual cycle of precipitation produce less-biased estimates of the annual cycle of regional precipitation than raw model output, and also show some skill at reconstructing interannual variations in regional precipitation. Most of the downscaling methods' skill is attributed to year-to-year ENSO variations and to the long-term trend in precipitation and large-scale fields.
While the goal of the present study is to investigate the skill of downscaling methods specifically for Indonesia, results are expected to be more generally applicable. In particular, the downscaling models derived from observations have been effectively used to debias the annual cycle of regional precipitation from global climate models. It is expected that the methods will be generally applicable in other regions where regional precipitation is strongly affected by the large-scale circulation.
In June 2009, a group of experts in climate science, crop modeling, and crop development gathered at Stanford University to discuss the major needs for successful crop adaptation to climate change. To focus discussion over the three day period, the meeting centered on just three major crops – rice, wheat, and maize – given that these provide the bulk of calories to most populations. The meeting also focused on two aspects of climate– extreme high temperatures and extreme low moisture conditions (i.e. drought) – that present substantial challenges to crops in current climate and are likely to become more prevalent through time. Other aspects of climate change such as more frequent flooding or saltwater intrusion associated with rising sea levels were not addressed, although they may also be important.
The current document is split into two sections:
The main target audiences for the document are donor institutions seeking to invest in climate adaptation, and climate and crop scientists seeking to set research agendas. We intend the term donor institutions to include private foundations, governments, and inter‐governmental organizations such as the World Bank and United Nations. An underlying assumption of the Stanford meeting was that there is a real and growing need to identify specific investment opportunities that will improve food security in the face of climate change. This is reflected, for instance, by the recent G8 announcement of a $20B investment in food security, the expectation of additional resources for adaptation from the Copenhagen Conference in 2009, and the emphasis of the Obama administration on food and climate issues.
Professor Walter P. Falcon, Deputy Director of the Center on Food Security and the Environment (FSE), former director of FSI, and Helen Farnsworth Professor of International Agricultural Policy, Emeritus has been recognized with an honorary degree from McGill University for his research aimed at reducing world hunger and enhancing global food security.
Professor Falcon's expertise is in food policy, commodity markets, trade policies, and regional development. Professor Falcon's current research focuses on agricultural decision-making in Indonesia and Mexico, biotechnology, climate change, and biofuels.
From 1972 to 1991, Professor Falcon served as professor of economics and director of Stanford University's Food Research Institute, after which he directed the Freeman Spogli Institute for International Studies until 1998. From 1998 to 2007 he co-directed the Center for Environmental Science and Policy. At Stanford he has also served as senior associate dean for the social sciences, a member of the academic senate, and twice a member of the University's Advisory Board.
Professor Falcon has also consulted with numerous international organizations, been a trustee of Winrock International, and was chairman of the board of the International Rice Research Institute (IRRI). From 1978 to 1980, he was a member of the Presidential Commission on World Hunger and in 1990 was named a Fellow of the American Agricultural Economics Association. From 1996-2001 he served as chairman of the board of the International Corn and Wheat Institute (CIMMYT), and from 2001-07 served on the board of the Center for International Forestry Research (CIFOR).
Falcon was cited as the outstanding 1958 graduate of Iowa State University in 1989 and in 1992 was awarded the prestigious Bintang Jasa Utama medal of merit by the government of Indonesia for twenty-five years of assistance to that country's development effort.
[See video interview with Chris Field and David Lobell here].
Biofuels such as ethanol offer an alternative to petroleum for powering our cars, but growing energy crops to produce them can compete with food crops for farmland, and clearing forests to expand farmland will aggravate the climate change problem. How can we maximize our "miles per acre" from biomass?
Researchers writing in
the May 7, 2009, edition of the journal Science say the best bet is to
convert the biomass to electricity rather than ethanol. They calculate
that, compared to ethanol used for internal combustion engines,
bioelectricity used for battery-powered vehicles would deliver an
average of 80 percent more miles of transportation per acre of crops,
while also providing double the greenhouse gas offsets to mitigate
climate change.
"It's a relatively obvious question once you ask it, but nobody had really asked it before," said study co-author Christopher B. Field, director of the Department of Global Ecology at the Carnegie Institution.
"The kinds of motivations that have driven people to think about
developing ethanol as a vehicle fuel have been somewhat different from
those that have been motivating people to think about battery electric
vehicles, but the overlap is in the area of maximizing efficiency and
minimizing adverse impacts on climate."
Field, who is
also a professor of biology at Stanford University and a senior fellow
at Stanford's Woods Institute for the Environment, is part of a
research team that includes lead author Elliott Campbell of the University of California-Merced and David Lobell of Stanford's Program on Food Security and the Environment.
The
researchers performed a life-cycle analysis of both bioelectricity and
ethanol technologies, taking into account not only the energy produced
by each technology, but also the energy consumed in producing the
vehicles and fuels. For the analysis, they used publicly available data
on vehicle efficiencies from the U.S. Environmental Protection Agency
and other organizations.
Bioelectricity was the clear
winner in the transportation-miles-per-acre comparison, regardless of
whether the energy was produced from corn or from switchgrass, a
cellulose-based energy crop. For example, a small SUV powered by
bioelectricity could travel nearly 14,000 highway miles on the net
energy produced from an acre of switchgrass, while a comparable
internal combustion vehicle could only travel about 9,000 miles on the
highway. (Average mileage for both city and highway driving would be
15,000 miles for a biolelectric SUV and 8,000 miles for an internal
combustion vehicle.)
"The internal combustion engine just isn't very efficient, especially
when compared to electric vehicles," said Campbell. "Even the best
ethanol-producing technologies with hybrid vehicles aren't enough to
overcome this."
Climate change
The
researchers found that bioelectricity and ethanol also differed in
their potential impact on climate change. "Some approaches to bioenergy
can make climate change worse, but other limited approaches can help
fight climate change," said Campbell. "For these beneficial
approaches, we could do more to fight climate change by making
electricity than making ethanol."
The energy from
an acre of switchgrass used to power an electric vehicle would prevent
or offset the release of up to 10 tons of CO2 per acre, relative to a
similar-sized gasoline-powered car. Across vehicle types and different
crops, this offset averages more than 100 percent larger for the
bioelectricity than for the ethanol pathway. Bioelectricity also offers
more possibilities for reducing greenhouse gas emissions through
measures such as carbon capture and sequestration, which could be
implemented at biomass power stations but not individual internal
combustion vehicles.
While the results of the study clearly favor bioelectricity over
ethanol, the researchers caution that the issues facing society in
choosing an energy strategy are complex. "We found that converting
biomass to electricity rather than ethanol makes the most sense for two
policy-relevant issues: transportation and climate," said Lobell. "But
we also need to compare these options for other issues like water
consumption, air pollution, and economic costs."
"There is a big strategic decision our country and others are making:
whether to encourage development of vehicles that run on ethanol or
electricity," said Campbell. "Studies like ours could be used to ensure
that the alternative energy pathways we chose will provide the most
transportation energy and the least climate change impacts."
This research was funded through a grant from the Stanford Global Climate and Energy Project, with additional support from the Stanford Program on Food Security and the Environment, UC-Merced, the Carnegie Institution for Science, and a NASA New Investigator Grant.
This paper is part 2 of a two-part study evaluating the climatic effect of one of the nation's most rapidly expanding metropolitan complexes, the Greater Phoenix, Arizona, region.
Part 1, using a set of sensitivity experiments, estimated the potential impact of observed landscape evolution, since the dawn of the Landsat satellite era on the near surface climate, with a primary focus on the alteration of the surface radiation and energy budgets and through use of high-resolution, 2km grid spacing, Regional Atmospheric Modeling System (RAMS) simulations with circa 1973, circa 1992, and circa 2001 landscape data sets.
In this paper, part 2, we address the role of the previously discussed surface budget changes and subsequent repartitioning of energy on the mesoscale dynamics and thermodynamics of the region, the effect on convective rainfall, and their association with the large-scale North American Monsoon System (NAMS). Our results show that contrasts in surface heating resulting from landscape change are responsible for the development of preferentially located mesoscale circulations, on most days, which were stronger for the 2001 compared to the 1973 landscape, due to increased planetary boundary layer (PBL) heating via enhanced turbulent heat flux.
The effect of these stronger circulations was to warm and dry the lower part of the PBL and moisten the upper part of the PBL for the 2001 relative to the 1973 landscape. The precise physical pathway(s) whereby precipitation enhancement is initiated with evolving landscape, since the early 1970s, reveals a complicated interplay among scales (from the turbulent to the synoptic scale) that warrants future research. Precipitation recycling, however, was found to be an important driver in the overall sustenance of rainfall enhancement.
Although this study was not designed to investigate other radiative forcing factors such as greenhouse gas emissions and aerosols, the results of our sensitivity experiments do suggest that regional land use change is an important element of climate change in semiarid environments characterized by large urban areas with scarce water resources.