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.
There is little disagreement now that the climate is changing, and that such changes could fundamentally affect humanity's collective ability to feed itself. However, there is little systematic knowledge of where climate effects will hit hardest and how agriculture might adapt to a rapidly changing climate.
Agriculture is the human enterprise most dependent on climate and natural resources, and is thus the sector that has the most to gain or lose from short- or long-run changes in the level or variability of climate. A growing literature seeks to understand the probable effects of climate change on agriculture, and improvements in our understanding of climate dynamics and crop response has begun to reduce some of the uncertainties inherent in projecting future impacts on agriculture. Nevertheless, there has been scant research conducted on the climate impacts on various crops and agroecosystems of central importance to the global poor. Furthermore, much of the existing literature assumes that farmers will automatically adapt to climate change and thereby lessen many of its potential negative impacts, taking for granted the monumental past efforts at the collection, preservation, and utilization of plant genetic resources on which much of farmer adaptation has historically depended.
Given potentially large changes in global temperature, regional precipitation patterns, and extreme weather events, we believe it is dangerous to assume that adaptation of cultivars will happen automatically. Extensive crop breeding that relies on access to genetic resources will almost certainly be required for crop adaptation under conditions of global climate change. Furthermore, substantial knowledge and insight is needed to gauge what types of diversity now exist in the gene banks, and what will be needed in the future. Fundamental questions remain to be addressed, for example: How are regional patterns of climate expected to change in the future, and how will these changes affect agro-ecosystems around the world? There are also several strategic investment issues to consider--which traits, which crops and which regions should be central to strategic decisions on ex situ genetic conservation? What steps should be taken to conserve the genetic diversity of the important but neglected minor crops where the number of accessions is currently low? Answers to these questions will be critical for promoting food security and ensuring human survival, and to date have received little or no attention in the scientific literature or broader policy arena.
This conference will seek to answer three main questions:
1) What and where are the largest threats to agro-ecosystems under future climate change? Here we will seek to identify both the nature and the location of the largest probable threats, a topic that to date has not been systematically undertaken for certain areas of interest.
2) Taken individually and together, what do these threats imply for crop genetic diversity on a regional or global level? I.e. which traits, which crops and which regions appear central to strategic decisions on ex situ genetic conservation?
3) What is the current state of genetic conservation with respect to these threats, and what does this imply about the sequencing of future efforts at ex situ conservation focus? For example, are there a set of minor crops important to food security that are both poorly represented in the gene banks and under great threat from future climate change?
Particular attention will be paid to those crops and cropping systems on which food insecure populations currently depend, and who would be least able to adapt in the absence of concerted public action to the contrary. We expect that this effort will be the first serious attempt to link crop genetic resource conservation to climate change and variability.
» A news article on recent investments being made by the Global Crop Diversity Trust, decisions which were informed by the Bellagio meeting.
Bellagio, Italy
We select a 30-day delay in monsoon onset as a threshold beyond which significant impact on the country's rice economy is likely to occur. To project the future probability of monsoon delay and changes in the annual cycle of rainfall, we use output from the Intergovernmental Panel on Climate Change AR4 suite of climate models, forced by increasing greenhouse gases, and scale it to the regional level by using empirical downscaling models.
Our results reveal a marked increase in the probability of a 30-day delay in monsoon onset in 2050, as a result of changes in the mean climate, from 9-18% today (depending on the region) to 30-40% at the upper tail of the distribution. Predictions of the annual cycle of precipitation suggest an increase in precipitation later in the crop year (April-June) of 10% but a substantial decrease (up to 75% at the tail) in precipitation later in the dry season (July-September). These results indicate a need for adaptation strategies in Indonesian rice agriculture, including increased investments in water storage, drought-tolerant crops, crop diversification, and early warning systems.
A new study published May 8th in the Proceedings of the National Academy of Sciences (PNAS) finds that Indonesian rice agriculture is greatly affected by short-run climate variability, and could be significantly harmed by long-run climate change. Indonesia is the fourth most populous country in the world, one of the world's largest producers and consumers of rice, and is characterized by a population of rural poor who depend on rice agriculture for their livelihood.
"Agriculture is central to human survival, and is probably the human enterprise most vulnerable to changes in climate", notes lead author Rosamond Naylor, Director of the Program on Food Security and the Environment at Stanford. "This is particularly true in countries such as Indonesia, with large populations of rural poor. Understanding the current and future effects of changes in climate on Indonesian rice agriculture will be crucial for improving the welfare of the country's poor".
Rice growers facing shortened rainy season
The PNAS study, entitled 'Assessing the risks of climate variability and climate change for Indonesian rice agriculture', was a joint effort among a team of scientists at Stanford University, the University of Washington, and the University of Wisconsin. The study finds that rice production in Indonesia is greatly affected by year-to-year climate variability -- in particular the variability caused by El Nino/Southern Oscillation (ENSO) events in the Pacific Ocean. During a warm ENSO event (or 'El Nino'), the arrival of the monsoon rains is delayed, disrupting the planting of the main rice crop and prolonging the 'hungry season' in Indonesia. "During a bad El Nino event, farmers literally wait months before they can plant their crop, resulting in a harvest that is months late and often much smaller in size", says Naylor.
The authors then analyzed how climate change could effect rainfall and agriculture in Indonesia. Using output from 20 global climate models (GCMs), running two emissions scenarios, and tailoring the GCM projections to the complex local topography of the Indonesian archipelago, the authors found that the probability of experiencing a harmful delay in monsoon rains could more than double in some of the most important rice growing regions in Indonesia.
"Most models predict that the rains will come later in Indonesia, it will rain a little harder once the monsoon begins, and then it will really dry up during the summer months," says David Battisti, co-author and atmospheric scientist at the University of Washington. "So Indonesia could be looking at a much shorter rainy season, with an almost rainless dry season in some areas, squeezing rice farmers on both ends".
While the study cannot directly address changes in the frequency or intensity of ENSO events under future climate change -- still an area of active research -- the authors conclude that even if there were no changes in the basic pattern of ENSO, Indonesian rice growers will be facing a significantly shortened rainy season. In the absence of adaptive measures, these growers could suffer greatly.
Adapting for change
What adaptive measures could be taken in the face of harmful short-run variability and long-run change in climate? In the short run, the science of ENSO prediction has advanced to the point that reasonably high-confidence ENSO forecasts are available at least two seasons in advance. A forecasting model developed by the authors is now being used to by the Indonesian Agricultural Ministry to anticipate and plan for ENSO events and their effects on agriculture. The authors are also working with Indonesian officials to develop longer-run strategies which address the anticipated effects of climate change on agriculture in the country. Such strategies could include investments in water storage, development of drought-tolerant crops, and crop diversification for those farmers at greatest risk.
Along with its important findings for Indonesian policy-makers, the study design itself is a novel contribution to the literature. "To our knowledge, our study is the first climate-agriculture study that uses projections from all available GCMs to look at climate effects in a specific region", explains Battisti. "Thus more than past efforts, our study captures the range of uncertainty across different projections of future climate, knowledge which will be crucial for long-run thinking about how to respond."
Battisti also notes that the use of empirical downscaling models in the study, which translate GCM output into useable regional forecasts of changes in climate, is a technique missing from most other studies of climate and agriculture in the tropics, an omission that could render their regional climate projections untrustworthy. Naylor adds: "From a scientific perspective, its imperative that we now replicate this kind of study elsewhere, in order to start building a more complete picture of the effects of climate change on agriculture." The team has begun a similar study in China this spring.
Richard and Rhoda Goldman Conference Room
The Jerry Yang and Akiko Yamazaki
Environment and Energy Building
Stanford University
473 Via Ortega, Office 363
Stanford, CA 94305
Rosamond Naylor is the William Wrigley Professor in Earth System Science, a Senior Fellow at Stanford Woods Institute and the Freeman Spogli Institute for International Studies, the founding Director at the Center on Food Security and the Environment, and Professor of Economics (by courtesy) at Stanford University. She received her B.A. in Economics and Environmental Studies from the University of Colorado, her M.Sc. in Economics from the London School of Economics, and her Ph.D. in applied economics from Stanford University. Her research focuses on policies and practices to improve global food security and protect the environment on land and at sea. She works with her students in many locations around the world. She has been involved in many field-level research projects around the world and has published widely on issues related to intensive crop production, aquaculture and livestock systems, biofuels, climate change, food price volatility, and food policy analysis. In addition to her many peer-reviewed papers, Naylor has published two books on her work: The Evolving Sphere of Food Security (Naylor, ed., 2014), and The Tropical Oil Crops Revolution: Food, Farmers, Fuels, and Forests (Byerlee, Falcon, and Naylor, 2017).
She is a Fellow of the Ecological Society of America, a Pew Marine Fellow, a Leopold Leadership Fellow, a Fellow of the Beijer Institute for Ecological Economics, a member of Sigma Xi, and the co-Chair of the Blue Food Assessment. Naylor serves as the President of the Board of Directors for Aspen Global Change Institute, is a member of the Scientific Advisory Committee for Oceana and is a member of the Forest Advisory Panel for Cargill. At Stanford, Naylor teaches courses on the World Food Economy, Human-Environment Interactions, and Food and Security.
Changes in the global production of major crops are important drivers of food prices, food security and land use decisions. Average global yields for these commodities are determined by the performance of crops in millions of fields distributed across a range of management, soil and climate regimes. Despite the complexity of global food supply, here we show that simple measures of growing season temperatures and precipitation--spatial averages based on the locations of each crop--explain about 30% or more of year-to-year variations in global average yields for the world's six most widely grown crops. For wheat, maize, and barley, there is a clearly negative response of global yields to increased temperatures. Based on these sensitivities and observed climate trends, we estimate that warming since 1981 has resulted in annual combined losses of these three crops representing roughly 40 MT or $5 billion per year, as of 2002. While these impacts are small relative to the technological yield gains over the same period, the results demonstrate already occurring negative impacts of climate trends on crop yields at the global scale.
The harmful environmental effects of livestock production are becoming increasingly serious at all levels-local, regional, national and global-and urgently need to be addressed, according to researchers from Stanford, the United Nations Food and Agriculture Organization (FAO) and other organizations. The researchers, representing five countries, presented their findings on Feb. 19 at the annual meeting of the American Association for the Advancement of Science (AAAS) in San Francisco during a symposium titled "Livestock in a Changing Landscape: Drivers, Consequences and Responses."
Large-scale livestock operations provide most of the meat and meat products consumed around the world-consumption that is growing at a record pace and is projected to double by 2050, said symposium organizer Harold A. Mooney, professor of biological sciences. "We are seeing tremendous environmental problems with these operations, from land degradation and air and water pollution to loss of biodiversity," he said, noting that the developing world is especially vulnerable to the effects of these operations.
Intensive and extensive systems
Symposium co-organizer Henning Steinfeld of the FAO Livestock Environment and Development initiative emphasized that intensive and extensive forms of production are beset with a range of different problems. In "intensive systems," animals are contained and feed is brought to them. "Extensive systems" generally refer to grazing animals that live off the land.
"Extensive livestock production plays a critical role in land degradation, climate change, water and biodiversity loss," Steinfeld said. For example, grazing occupies 26 percent of the Earth's terrestrial surface, and feed-crop production requires about a third of all arable land, he said. Expansion of livestock grazing land is also a leading cause of deforestation, especially in Latin America, he added. In the Amazon basin alone, about 70 percent of previously forested land is used as pasture, while feed crops cover a large part of the remainder.
"We are seeing land once farmed locally being transformed to cropland for industrialized feed production, with grasslands and tropical forests being destroyed in these land use changes, with resources feeding livestock rather than the humans who previously depended on those lands," added Mooney, who co-chaired the scientific advisory panel for the United Nations-initiated Millennium Ecosystem Assessment.
Climate change
According to the FAO, when emissions from land use are factored in, the livestock sector accounts for 9 percent of all carbon dioxide emissions derived from human-related activities, as well as 37 percent of methane emissions-primarily gas from the digestive system of cattle and other domesticated ruminants-and 65 percent of nitrous oxide gases, mostly from manure.
The problems surrounding livestock production cannot be considered in isolation, nor are they limited to the environmental impact, Mooney said, noting that economic, social, health and environmental perspectives "will be critical to solving some of these problems. We hope to develop a greater understanding of these complex issues so that we may encourage policies and practices to reduce the adverse effects of livestock production, while ensuring that humans are fed and natural resources are preserved, today and in the future."
Kathy Neal is communications manager of the Woods Institute for the Environment.
The Amazon Basin is one of the world's most important bioregions, harboring a rich array of plant and animal species and offering a wealth of goods and services to society. For years, ecological science has shown how large-scale forest clearings cause declines in biodiversity and the availability of forest products. Yet some important changes in the rainforests, and in the ecosystem services they provide, have been underappreciated until recently. Emerging research indicates that land use in the Amazon goes far beyond clearing large areas of forest; selective logging and other canopy damage is much more pervasive than once believed. Deforestation causes collateral damage to the surrounding forests - through enhanced drying of the forest floor, increased frequency of fires, and lowered productivity. The loss of healthy forests can degrade key ecosystem services, such as carbon storage in biomass and soils, the regulation of water balance and river flow, the modulation of regional climate patterns, and the amelioration of infectious diseases. We review these newly revealed changes in the Amazon rainforests and the ecosystem services that they provide.
Most research on the agricultural impacts of climate change has focused on the major annual crops, yet perennial cropping systems are less adaptable and thus potentially more susceptible to damage. In regions where perennial crops are economically and culturally important, improved assessments of yield responses to future climate are needed to prioritize adaptation strategies. These impact assessments, in turn, must rely on climate and crop models that contain often poorly defined uncertainties. We evaluated the impact of climate change on six major perennial crops in California: wine grapes, almonds, table grapes, oranges, walnuts, and avocados. Outputs from multiple climate models were used to evaluate climate uncertainty, while multiple statistical crop models, derived by resampling historical databases, were used to address crop response uncertainties. We find that, despite these uncertainties, climate change in California is very likely to put downward pressure on yields of almonds, walnuts, avocados, and table grapes by 2050. Without CO2 fertilization or adaptation measures, projected losses range from 0 to >40% depending on the crop and the trajectory of climate change. Climate change uncertainty generally had a larger impact on projections than crop model uncertainty, although the latter was substantial for several crops. Opportunities for expansion into cooler regions were identified, but this adaptation would require substantial investments and may be limited by non-climatic constraints. Given the long time scales for growth and production of orchards and vineyards (30 years), climate change should be an important factor in selecting perennial varieties and deciding whether and where perennials should be planted.
Biofuels are a hot topic in both the academic literature and the popular press. Much of the current debate over biofuels, however, is devoted to narrow issues of energy conversion to the exclusion of understanding the broader implications surrounding their rapid development. This project embraces these larger questions, examining the role of biofuels development on global land use change and climate, on food markets, and on global food security. Primary questions include: