WASHINGTON, DC -- While global warming may make the achievement of sustainable agricultural production more difficult, especially in developing countries, a bigger threat may come from more immediate concerns, such as lags in the spending on agricultural research needed for development of new technology, according to a new issues brief published by Resources for the Future (RFF).
Authored by RFF's Pierre Crosson, the paper, "Impacts of Climate Change on Agriculture," is part of RFF's series of issues briefs on global climate change.
It can be downloaded on the internet at http://www.rff.org/issues/home.htm.
"The potential impacts of climate change on agriculture at both the global and national level are important to the United States because our agriculture system is so inextricably entwined with global agriculture," Crosson says. "We cannot understand what might happen in the U.S. without taking account of impacts elsewhere in the world."
In his paper, Crosson discusses the various estimates of climate change impacts on agriculture from the 1996 report by the Intergovernmental Panel on Climate Change (IPCC), a body of leading natural and social scientists from around the world. The estimates are based on grain production data for industrialized Western countries and developing countries in Asia, Africa and Latin America (grain is often used as a proxy for all food because over half of all food calories consumed in the world come from grain). The impact estimates included four scenarios that involved various concentrations of carbon dioxide in the atmosphere and farmers both adjusting and not adjusting their methods to offset climate change impacts.
Crosson points out that the IPCC climate models are in general agreement about the expected effects on global climate averages -- that surface temperatures will rise 1.0-3.5 degrees Celcius, and that the northern latitudes will warm more than the tropics. But with respect to regional changes, the models diverge sharply, which creates great uncertainty about the impacts on agriculture. As far as the models go, however, they suggest that climate change will modestly reduce grain production in developing countries while possibly improving it in industrialized countries, Crosson says.
Crosson notes two reasons for this discrepancy: the "physical" factor -- that most industrialized countries are in the northern latitudes and their agricultures will benefit from the longer growing seasons that a warmer climate would bring; and, the "eco-structural" factor -- that industrialized countries have much greater economic resources that can be devoted to helping farmers adjust to climate change and their institutional structures are more efficient in mobilizing the resources needed to pursue specific social objectives.
"It's important to remember that the eco-structural weaknesses among developing countries are not forever fixed," Crosson says. "In east and southeast Asia, for example, agricultural performance over the last 10 or 15 years has impressively improved. Farmers have adopted new, more productive technologies as they have become available, and production, both per person and per hectare, has increased. The Asian experience provides some promise that by the time climate change begins to negatively impact developing countries, they will have developed a capacity to adjust to it well beyond what they could accomplish under present conditions."
"The possible impacts of climate change on agriculture in developing countries are, at most, of secondary importance relative to other immediate problems," Crosson concludes. "Compared to the long time it will take for climate change impacts to become evident, many developing countries, especially in Africa, face more severe immediate problems, which constrain the ability of farmers to respond adequately to rising demands for food and other agricultural commodities."
Crosson notes that natural resource degradation is also serious in some parts of these countries, but recent studies indicate that in general and contrary to a widely held view, degradation of land and water resources is not an inherent threat to agricultural sustainability in developing countries. The critical issue, Crosson says, is whether, in the future and over the next several decades, these countries can develop the capacity to increasingly expand the knowledge base and the institutional resources needed to achieve sustainable agricultural systems.
As decisionmakers prepare for domestic policy debates and the ongoing international negotiations under the Framework Convention on Climate Change, RFF's climate issues briefs provide topical, timely, and non-technical information and analysis. They are intended to integrate the various aspects of climate change with critical reviews of existing literature and original research at RFF on climate policy, energy markets, agriculture, water and forest resource management, technological change, air pollution, and sustainable development.
GLOBAL CLIMATE CHANGE can be caused by an increase in the atmospheric concentration of greenhouse gases which inhibits the transmission of some of the sun's energy from the earth's surface to outer space. These gases include carbon dioxide, water vapor, methane, chlorofluorocarbons (CFCs), and other chemicals. The increased concentrations of greenhouse gases result in part from human activity -- deforestation; the burning of fossil fuels such as gasoline, oil, coal and natural gas; and the release of CFCs from refrigerators, air conditioners, etc.
Although there is a strong scientific consensus that increasing atmospheric concentrations of greenhouse gases will, in time, result in higher global temperatures, there is an enormous amount of controversy surrounding questions of how much temperature rise is likely and when it will occur. There are differing opinions, domestically and internationally, about the answers to these questions and, therefore, about the seriousness of risks posed by climate change, about the costs of responding to these risks, and about the sharing of the costs among countries. Advocates warn that climate change is one of the greatest threats facing humankind and urge immediate and strong responses to reduce greenhouse gases. Skeptics contend that there is inadequate scientific documentation of the risks of climate change, and that little action should be taken today other than more research and continued development of technological options.
Disagreements over the scientific evidence relating to climate change and its consequences, together with differing national interests, surface frequently in the ongoing efforts of the international community to negotiate goals and actions under the Framework Convention on Climate Change. The Convention is an agreement among more than 150 countries to develop programs to slow climate change, and to consider climate change in the management of agriculture, energy, water and other natural resources.
SUSTAINABLE DEVELOPMENT is a concept that implies accepting that continued economic growth is necessary to meet the needs of the world's population particularly in the developing world, but at the same time maintaining the ecological and human knowledge systems needed to protect the interests of future generations. It emphasizes better management of finite resources (particularly energy) and the increased use of renewable resources.