Climate Variability and Development

Agreement on an international convention to mitigate the buildup of greenhouse gases could be one of UNCED' s important achievements. However, it is also important that the conference address the problem of existing climate variability, which at present complicates the sustainable development of resources in developed countries and, even more so, in developing countries. Agriculture illustrates the vulnerability of societies to this variability, yet it also demonstrates a potential for adaptability. Agriculture's response to drought suggests that better means of adapting to existing climate variability would provide immediate benefits and would likely expand the range of options available to cope with climate change in the future.

An effective international response to global climate change must involve components of both a workable mitigation strategy and an improved capacity for adaptation.

While there is an urgent need to investigate international strategies aimed at mitigating the buildup of greenhouse gases, it is also important that international forums address the problem of existing climate variability. For even if the world community agrees to strong controls on the emissions of greenhouse gases, these controls will not eliminate such emissions nor will they remove CO2 and other greenhouse gases from the atmosphere; thus, while emissions controls could greatly mitigate the potential impact of global climate change, they probably will not prevent such change. Furthermore, even if no threat of greenhouse warming existed, climate variability and extreme climatic events would continue to complicate the sustainable development of agriculture, water, and other resources in developed countries and, even more so, in developing countries. Better means of adapting to existing climate variability would have important immediate benefits and might also provide ways to ease adaptation to global climate change in the future. Thus adaptation and mitigation should be viewed as complementary approaches. An effective international response to global climate change must involve components of both a workable mitigation strategy and an improved capacity for adaptation.

In discussing efforts to adapt to existing climate variability and how these efforts relate to lessening the potential effect of global climate change and improving the prospects for sustainable development, it is instructive to examine agriculture's options for improved adaptation in drought-prone regions. Recently, a panel of the National Academy of Sciences concluded that global agriculture may be able to adapt more quickly to changing climate conditions than other natural resource sectors such as water, forests, and unmanaged ecosystems. Water resources, for example, are even more dependent than is agriculture on a large, fixed infrastructure (dams, irrigation systems, and the like). Forest resources may be slow to adapt due to the long time-span between harvests and regrowth. And unmanaged natural ecosystems—wetlands, forests, and tundras, for example—may be the most vulnerable of all these resources because of their inability to adapt to rapidly changing conditions. Nevertheless, despite the higher potential for adaptation within the agricultural sector, agriculture probably best illustrates the vulnerability of different societies to existing climate variability and future climate change.

Climate and societal vulnerability

Droughts in sub-Saharan Africa have been associated with widespread famine. For example, it has been estimated that during the drought in the Sahel in the early 1970s there were 100,000 famine-related deaths. While it is clear that famines have occurred during periods of prolonged drought in sub-Saharan Africa, it is less clear what specific role drought has played in causing famine. Droughts do not necessarily result in famines, and famines do not necessarily result from droughts. Other key factors that have contributed to famine conditions include lack of availability of or access to technology and information, domestic and international economic policy, political turmoil, and even war.

Many African societies are remarkably well adapted to arid conditions. Drought, however, often exacerbates other environmental stresses such as over-grazing, and existing economic and political problems such as deficiencies in the food distribution system or rural poverty. Comprehending the role that drought plays in causing famine requires an understanding of how drought interacts with these other factors.

The Great Plains region of the United States, like the Sahel region of Africa, is prone to prolonged periods of severe drought; however, the social effects of these drought periods have been far less devastating than those in the Sahel. The "dust bowl" years of the 1930s represent the most serious recorded deviation from normal weather patterns in much of the Great Plains. For the decade as a whole, temperatures averaged 1° C above normal in some states, and precipitation was as much as 15 percent lower than normal. In certain years (1934 and 1936 particularly) conditions were much more severe; average wheat yields in the Great Plains states declined by a third, and nearly 30 percent of the acreage planted to wheat during the decade had to be abandoned. The social effects of the drought were also severe, with considerable loss of farm income and large-scale migration of people out of the area. Because the drought occurred at a time of national and world economic depression, the economic distress experienced in the region cannot be attributed solely to it.

Severe drought also hit the Great Plains during the 1950s, in 1974–1976, and again in 1987–1989; none of these droughts equalled the dust bowl years in terms of length, severity, or extent of social disruptions. During these more recent droughts, loss of crop yields was significant; however, migration from the region was minor, and there was little evidence of social collapse, such as occurred in the 1930s. The drought of the late 1980s resembled the worst of the dust bowl years in terms of severity and geographical distribution. But in spite of crop losses of 20 to 50 percent, the 1987–1989 drought was not as economically and socially disruptive as that of the 1930s. Large grain surpluses were available from relatively wet years preceding the drought, thus preventing food shortages. Government drought relief in the form of services, technical assistance, and insurance softened the blow to fanners.

The impacts of climate variability and change may be as much, if not more, a product of social and economic conditions as of climate itself.

This resilience—not so much to drought per se as to its severe ramifications—has been accomplished through a strong agricultural research establishment that has led to improved crop varieties and land management techniques. Of no less importance have been market interventions that somewhat damped what were once wild oscillations in commodity prices and crop insurance, which provided protection for farm family income in bad years. The existence of a strong system of public education has also contributed to the increased resilience to drought in the region.

The model of drought adaptation used in the Great Plains does not necessarily represent the only or the best approach for developing countries to follow today, not least because these efforts have required large investments of resources that only a rich nation could have made on its own in the past and that cannot now be made in most developing nations without international assistance. It is also important to recognize that some of the drought resilience that technology has brought to the Great Plains has been at the cost of environmental degradation—groundwater pollution by nitrates and pesticides, depletion or mining of groundwater that might have been available for emergency use, and the loss of fisheries and wildlife habitat due to the damming of rivers. This raises important questions about the long-term sustainability of current agricultural practices that have allowed farmers to adapt to climatic variability. New technologies and techniques are needed to repair environmental damage already done by some of these practices in the Great Plains and in other agricultural regions of the United States. The environmental consequences of future drought-resistance efforts in the agricultural sector will have to be reckoned in advance and new environmentally benign technologies and techniques will be needed to further those efforts.

Climate change and sustainable development

Much of what has already been learned about coping with the agricultural effects of drought Will be relevant for responding to future climate change.

Because scientists cannot predict the future climate of regions in a greenhouse-warmed world, any discussion of possible adaptations to climate change must be labeled as speculation at best. However, there is confidence about two matters regarding climate change and the adaptation of agriculture. First, it is clear that a strong research establishment will be essential to maintaining a steady stream of adaptations. Second, it is clear that the rate of response and adaptation will increase if farmers and their governments perceive that climate is actually changing, or if scientific evidence of forthcoming change becomes incontrovertible. This perception or evidence is likely to affect response and adaptation to climate change in other resource sectors, such as water or forestry, as well.

The relatively optimistic view presented here of the developed world's current and future agricultural capability to cope with climate change is based on an implicit assumption that the resources available to agricultural research establishments in the developed world will be adequate to the task and that new tools, such as biotechnology, may make rapid adaptation easier in the future. This may not be true in the developing world, where the margin of survival is much smaller and where the impacts of existing climate variability are often not well managed. Although there is no reason to believe that the extent of greenhouse-induced climate change will be more severe in developing countries than in developed countries, the developing countries are likely to be more vulnerable to such change because of their more limited ability to respond to uncertain conditions.

Many climate-sensitive regions of the developing world are clearly beseiged by problems of underdevelopment, poverty, and environmental degradation. Brazil's semiarid northeast is a case in point. Much of this area is densely populated, agriculturally marginal, and prone to severe and prolonged periods of drought. The area is particularly vulnerable to the effects of drought because it is impoverished, mostly rural, and highly dependent on agriculture. The impacts of drought—unemployment, declining income, falling agricultural production, and rising food prices—on the area's rural population often reinforce one another. Many rural workers and their families are thus forced to migrate to large cities in search of employment, contributing to Brazil's rising urban poverty. Recently, these workers have been moving into the Amazon region as well, increasing pressures for deforestation.

Developing countries' potential vulnerability to climate change suggests the need for both mitigating the emission of greenhouse gases and improving the prospects for achieving sustainable economic development.

Adding to the area's problems is the prospect of its vulnerability to the effects of a greenhouse gas-induced climate change. On the basis of climate-change scenarios drawn from general circulation models, the Intergovernmental Panel on Climate Change (an international board of scientific and policy experts) has identified two broad sets of regions that appear most vunerable to climate change. Northeastern Brazil is among the set of semiarid tropical and subtropical regions so identified. While the uncertainty surrounding predictions of regional vulnerability to climate change remains great, it is likely that global climate change will exacerbate this area's climate problems, with major implications for sustainable resource development.

The plight of developing countries and their potential vulnerability to climate change argues strongly not only for pushing forward with international efforts to mitigate the emission of greenhouse gases but also for addressing the need for improving the prospects for achieving sustainable economic development. With respect to many of the world's developing regions, it seems clear that the climate change issue cannot be separated from the more immediate problems of development. Indeed, improvement of strategies for dealing with current climate variability is of interest to both developed and developing countries. The United Nations Conference on Environment and Development could offer a valuable forum for devising cooperative efforts among countries to improve strategies for coping with existing climate variability. Such efforts would greatly enhance the prospects for sustainable use of natural resources in both the developed and developing worlds, and thus improve prospects for both mitigating and adapting to climate change in the future.

Peter M. Morrisette is a fellow in the Energy and Natural Resources Division at RFF. Norman J. Rosenberg is a senior fellow in the division and director of RFF's Climate Resources Program.

A version of this article appeared in print in the January 1992 issue of Resources magazine.