Presentation from the session session "Biofuels, Tropical Deforestation, and Climate Policy: Key Challenges and Opportunities" at the annual AAAS meeting, Feb 14 2009.
Higher growing season temperatures can have dramatic impacts on agricultural productivity, farm incomes, and food security. We used observational data and output from 23 global climate models to show a high probability (>90%) that growing season temperatures in the tropics and subtropics by the end of the 21st century will exceed the most extreme seasonal temperatures recorded from 1900 to 2006. In temperate regions, the hottest seasons on record will represent the future norm in many locations. We used historical examples to illustrate the magnitude of damage to food systems caused by extreme seasonal heat and show that these short-run events could become long-term trends without sufficient investments in adaptation.
This paper
presents data from six of the first countries incorporated into the
Agricultural Lives of the Poor project: Ghana, Guatemala, India, Malawi, Uganda,
and Vietnam. Datasets were selected
based on availability and depth of detail on consumption expenditures, sources
of income, and agricultural practices. Each of these survey components is necessary in order for ALP
to focus on net consumption/production at the household level, and to
understand expenditure and consumption behavior. Net consumption and production data of individual crops and
food groups is further disaggregated by subgroups formed on characteristics
that include economic status, household attributes, livelihood strategies,
calories available, landholding, tenure types, and agricultural input use.
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Program on Food Security and the Environment, Stanford University
Berkeley and Stanford - Climate change could increase the likelihood of civil war in sub-Saharan Africa by over 50 percent within the next two decades, according to a new study led by a team of researchers at University of California, Berkeley, Stanford University, New York University and Harvard University, and published in today's (Monday, Nov. 23) online issue of the journal Proceedings of the National Academy of Sciences (PNAS).
The study provides the first quantitative evidence linking climate change and the risk of civil conflict. It concludes by urging accelerated support by African governments and foreign aid donors for new and/or expanded policies to assist with African adaptation to climate change.
"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," said Marshall Burke, the study's lead author, a graduate student at UC Berkeley's Department of Agricultural and Resource Economics, and research associate at the Program on Food Security and the Environment. "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."
"We were definitely surprised that the linkages between temperature and recent conflict were so strong," said Edward Miguel, professor of economics at UC Berkeley and faculty director of UC Berkeley's Center for Evaluation for Global Action. "But the result makes sense. The large majority of the poor in most African countries depend on agriculture for their livelihoods, and their crops are quite sensitive to small changes in temperature. So when temperatures rise, the livelihoods of many in Africa suffer greatly, and the disadvantaged become more likely to take up arms."
Understanding the causes and consequences of civil strife in much of the African continent has been a major focus of the social sciences for decades, said Miguel, given the monumental suffering has resulted from it.
In the study, the researchers first combined historical data on civil wars in sub-Saharan Africa with rainfall and temperature records across the continent. They found that between 1980 and 2002, civil wars were significantly more likely in warmer-than-average years, with a 1 degree Celsius increase in temperature in a given year raising the incidence of conflict across the continent by nearly 50 percent.
Building on this historical relationship between temperature and conflict, the researchers then used projections of future temperature and precipitation change to quantify future changes in the likelihood of African civil war. Based on climate projections from 20 global climate models, the researchers found that the incidence of African civil war could increase 55 percent by 2030, resulting in an additional 390,000 battle deaths if future wars are as deadly as recent wars.
All climate models project rising temperatures in coming decades, said David Lobell, study co-author and an assistant professor of environmental earth system science at Stanford and center fellow at Stanford's Program on Food Security and the Environment, a joint program of the Freeman Spogli Institute for International Studies and the Woods Institute for the Environment.
"On average, the models suggest that temperatures over the African continent will increase by a little over 1 degree Celsius by 2030," he added. "Given the strong historical relationship between temperature rise and conflict, this expected future rise in temperature is enough to cause big increases in the likelihood of conflict."
To confirm that this projection was not the result of large effects in just a few countries or due to overreliance on a particular climate model, the researchers recalculated future conflict projections using alternate data. "No matter what we tried - different historical climate data, different climate model projections, different subsets of the conflict data - we still found the same basic result," said Lobell.
It's easy to think of climate change as a long way off, said the researchers, but their study shows how sensitive many human systems are to small increases in temperature, and how fast the negative impacts of climate change could be felt.
"Our findings provide strong impetus to ramp up investments in African adaptation to climate change, for instance by developing crop varieties less sensitive to extreme heat and promoting insurance plans to help protect farmers from adverse effects of the hotter climate," said Burke.
Applying findings from this study could prove useful to policy makers at the upcoming Copenhagen negotiations in December in determining both the speed and magnitude of response to climate change, the authors said.
"If the sub-Saharan climate continues to warm and little is done to help its countries better adapt to high temperatures, the human costs are likely to be staggering," said Burke.
Armed conflict within nations has had disastrous humanitarian
consequences throughout much of the world. Here we undertake the first
comprehensive examination of whether global climate change will exacerbate
armed conflict in sub-Saharan Africa. We find strong historical linkages
between civil war and temperature on the continent, with warmer years leading
to significant increases in the likelihood of war. When combined with climate
model projections of future temperature trends, this historical response to
temperature suggests a roughly 60% increase in armed conflict incidence by
2030, or an additional 390,000 battle deaths if future wars are as deadly as
recent wars. Our results suggest
an urgent need to reform African governments' and foreign aid donors' policies
to deal with rising temperatures.
Violent conflicts claim 3,000 lives per day through wars, bombings and attacks that dominate the news media. Meanwhile, behind the headlines, 20,000 people die each day from causes related to hunger and poverty. Physical security and food security are deeply connected. Over a billion people suffer from chronic food insecurity, a situation that feeds violent conflict and weakens national and international security. Food insecurity is especially problematic in agricultural regions where income growth is constrained by resource scarcity, disease, and environmental stress.
Gerald Nelson, Senior Research Fellow at IFPRI will be giving a talk on Climate and Agriculture in the Context of Copenhagen. Nelson received his PhD from Stanford University in 1982. Since that time he has served as the Agricultural Development Council representative at the University of the Philippines, Los Banos from 1982-85, and as assistant, associate and full professor in the Department of Agricultural and Consumer Economics, University of Illinois, Urbana-Champaign from 1985 to 2008. He is now an agricultural economist at the International Food Policy Research Institute (IFPRI) in Washington, DC specializing in climate change.
Jerry Yang and Akiko Yamazaki
Environment and Energy Building (Y2E2)
Room 300
Gerald Nelson
Senior Research Fellow
Speaker
International Food Policy and Research Institute
Seminars
Climate and Agriculture: Models, Impacts, and Adaptation Strategies
Recent work has shown that current bio-energy policy directives may have harmful, indirect consequences, affecting both food security and the global climate system. An additional unintended but direct effect of large-scale biofuel production is the impact on local and regional climate resulting from changes in the energy and moisture balance of the surface upon conversion to biofuel crops. Using the latest version of the WRF modeling system we conducted twenty-four, midsummer, continental-wide, sensitivity experiments by imposing realistic biophysical parameter limits appropriate for bio-energy crops in the Corn Belt of the United States. In the absence of strain/crop-specific parameterizations, a primary goal of this work was to isolate the maximum regional climate impact, for a trio of individual July months, due to land-use change resulting from bio-energy crops and to identify relative importance of each biophysical parameter in terms of its individual effect. Maximum, local changes in 2 m temperature of the order of 1C occur for the full breadth of albedo (ALB), minimum canopy resistance (RCMIN) and rooting depth (ROOT) specifications, while the regionally (105W-75W and 35N-50N) and monthly averaged response of 2 m temperature was most pronounced for the ALB and RCMIN experiments, exceeding 0.2C. The full range of the albedo variability associated with biofuel crops may be sufficient to drive regional changes in summertime rainfall. Individual parameter effects on 2 m temperature are additive, highlight the cooling contribution of higher leaf area index (LAI) and ROOT for perennial grasses (e.g., Miscanthus) versus annual crops (e.g., maize), and underscore the necessity of improving location- and vegetation-specific representation of RCMIN and ALB.
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.
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.
"We were definitely surprised that the linkages between temperature and recent conflict were so strong," said Edward Miguel, professor of economics at UC Berkeley and faculty director of UC Berkeley's Center for Evaluation for Global Action. "But the result makes sense. The large majority of the poor in most African countries depend on agriculture for their livelihoods, and their crops are quite sensitive to small changes in temperature. So when temperatures rise, the livelihoods of many in Africa suffer greatly, and the disadvantaged become more likely to take up arms."