(June 2007) In February 2007, the Intergovernmental Panel on Climate Change (IPCC), a panel of international experts assessing the current scientific knowledge on climate asserted that warming of the earth's climate system is "unequivocal."1 The panel's conclusions are based on mounting evidence of shifts in the climate and consequent effects on ecological processes and biodiversity. Although some estimates of the health effects of climate change have been undertaken, there is still no clear understanding of the potential social effects.
The world's less industrialized regions are particularly vulnerable to the effects of climate change. In rural areas, specifically, environmental change has immediate and direct effects on the health and well-being of millions of households that depend on natural resources for their basic livelihoods.2
When weather changes reduce families' livelihood options, these changes can act as a "push" factor: People leave resource-dependent rural areas and create new migration patterns.3 Because migration represents a tremendous force of social change,4 the potential for climate change to increase migration deserves careful consideration and policy attention.
Rural Livelihoods and Climate Vulnerability
Rural households tend to rely heavily on climate-sensitive resources such as local water supplies and agricultural land; climate-sensitive activities such as arable farming and livestock husbandry; and natural resources such as fuelwood and wild herbs.5 Climate change can reduce the availability of these local natural resources, limiting the options for rural households that depend on natural resources for consumption or trade. Land may become less fertile; fewer reeds may be available for basketmaking; there may be less local fuelwood for cooking.
Of course, shifts in climate will bring different changes to different regions. Some areas may see greater natural resources because of increased rainfall, for example. But on balance, the poorest regions are most likely to suffer because they are least able to adjust to new conditions.
A recently released IPCC report suggests farmers in warmer and drier conditions in the Sahelian region of Africa have already curtailed their cropping seasons.6 Yields from rain-fed agriculture are expected to fall as much as 50 percent in some poor African countries. Fisheries production will likely also decline, according to the report. Rural regions in Latin America are also expected to be affected. In the region's drier areas, climate change is expected to lead to increases in the saline content of the soil, which reduces crop productivity. As previously productive lands become more arid, Latin America could also see greater desertification.
Migration and Climate
In the face of climate-related environmental change, such as the decline of productive agricultural land, rural residents may be forced to migrate in search of work. Migrants who find work often remit portions of their salary back home. Their families in the home communities may use the remittances to buy substitutes for goods previously produced or harvested from the local environment. For example, store-bought food may substitute for food previously grown on homestead plots.7
A link between migration and climatic factors, such as temperature and precipitation, has been documented in several rural regions of developing countries. In Burkina Faso, for example, residents of dry, rural areas are likely to migrate to rural regions with greater rainfall.8 In this way, migration may be a long-term response to the threat of recurrent droughts. Still, only short-distance moves appear affected by climactic factors, since international migration tends to be less common in a period of rainfall shortage, perhaps because of the investment required for an international move.
Migration is one of many survival strategies also used by Ethiopian households in times of environmental stress. Other survival strategies include using food reserves, seeking local nonfarm employment, selling livestock, borrowing food, or selling household and farm equipment. Still, once these livelihood options are exhausted, people often migrate to a new area.9
Although climate change is occurring and will continue, governments have undertaken little policy action to reduce climate-related migration, particularly in rural regions of less developed countries. Such policies need not be climate-specific, but could serve to enhance families' livelihood options, making them more resilient if their resource-base changes. In this way, development efforts and programs to reduce poverty will lessen livelihood vulnerability, ultimately reducing the need for families to migrate because of climate change.
In addition to practical implications, there are ethical dimensions to the link between climate change, poverty, and migration.. Although residents of less industrialized countries have contributed little to climate change, they are going to suffer disproportionately from the effects.10 The disadvantage already characterizing resource-dependent rural households may be exacerbated in the face of future changes in regional precipitation and temperature patterns.
Lori M. Hunter was a Bixby Visiting Scholar at the Population Reference Bureau, and is associate professor of sociology and environmental studies at the University of Colorado, Boulder.
- Intergovernmental Panel on Climate Change (IPCC), Climate Change 2007: The Physical Science Basis. Summary for Policymakers (Geneva: World Meteorological Organization (WMO) and UN Environment Programme (UNEP) IPCC, 2007), accessed online at http://ipcc-wg1.ucar.edu/, on June 1, 2007.
- Izabella Koziell and Jacqueline Saunders, eds., Living Off Biodiversity: Exploring Livelihoods and Biodiversity (London: International Institute for Environment and Development, 2001); and Charlie Shackleton and Sheona Shackleton, "The Importance of Non-Timber Forest Products in Rural Livelihood Security and as Safety Nets: A Review of Evidence From South Africa," South African Journal of Science 100 (2004): 658-64.
- Diane Bates and Thomas Rudel, "Climbing the Agricultural Ladder: Social Mobility and Motivations for Migration in an Ecuadorian Colonist Community," Rural Sociology 69, no. 1 (2004): 59-76.
- Roger-Mark DeSouza, "Using Return Migration as a Development Tool—Are the Right Policies in Place?" (2006), accessed online at www.prb.org, on June 1, 2007; and Philip Martin and Elizabeth Midgley, "Immigration: Shaping and Reshaping America, 2d ed., Population Bulletin 61, no. 4 (2006), accessed online at www.prb.org, on June 1, 2007.
- Shackelton and Shackelton, "The Importance of Non-Timber Forest Products in Rural Livelihood Security and as Safety Nets."
- IPCC Working Group II Contribution to the Fourth Assessment Report, Climate Change 2007: Climate Change Impacts, Adaptation and Vulnerability (Geneva: WHO and UNEP IPCC, 2007), accessed online at www.ipcc.ch, on June 1, 2007.
- Lori M Hunter, Wayne Twine, and Laura Patterson, "Locusts Are Now Our Beef: Adult Mortality and Household Dietary Use of Local Environmental Resources in Rural South Africa," Scandinavian Journal of Public Health 17, no. 5 (2007): 1-10.
- Sabine Henry, Bruno Schoumaker, and Cris Beauchemin, "The Impact of Rainfall on the First Outmigration: A Multi-Level Event-History Analysis in Burkina Faso," Population and Environment 25, no. 5 (2004): 423-60.
- Elisabeth Meze-Hausken, "Migration Caused by Climate Change: How Vulnerable Are People in Dryland Areas?" Mitigation and Adaptation Strategies for Global Change 5, no. 4 (2004): 379-406.
- Hans G. Bohle, Thomas E. Downing, and Michael J. Watts, "Climate Change and Social Vulnerability: Toward a Sociology and Geography of Food Insecurity," Global Environmental Change 4, no. 1 (1994): 37-48; and Jouni Paavola, "Justice in Adaptation to Climate Change in Tanzania," in Fairness in Adaptation to Climate Change, ed. W. Neil Adger et al. (Cambridge, MA: MIT Press: 2006): 223-37.