Thomas F. Homer-Dixon, Director, Peace and Conflict Studies Program, University of Toronto

September 28, 2000—In the last few decades on the Negros Island of the Philippines, the practice of swidden agriculture along with population growth and migration have led to severe erosion and destruction of cropland. This environmental destruction has combined with extreme poverty and the weak governmental structures to contribute to rural insurgency and guerrilla warfare and violence, according to Thomas Homer-Dixon, director and co-collaborator on multiple projects looking at environmental scarcity and violence. He elaborated on a two-step causal model of environmental contributions to violent conflict within developing countries, using the Philippines example to illustrate the causal chain. Homer-Dixon presented some of these key findings from his various research projects, which are summarized in his Princeton University Press book, Environment, Scarcity, and Violence (1999) at a public meeting sponsored by the Environmental Change and Security Project.

While there are many renewable resources, Homer-Dixon and his colleagues focused on the three key resources of cropland, fresh water, and forests within the context of three sources of scarcity. First, Homer-Dixon identified supply-induced scarcity, which is caused by the loss of resources such as a lack of quality drinking water or fertile land. Second, population growth and/or migration can increase the per person demand leading to demand-induced scarcity. Third, a skewed or disproportionate distribution of, or access to, resources is what Homer-Dixon terms structural scarcity.

Homer-Dixon's environmental scarcity research focused on two types of interactions using the three types of scarcities: (1) resource capture when resource access is shifted in favor of powerful groups (what economists term rent-seeking); and (2) ecological marginalization, where the combined impact of population growth and unequal resource access on a decrease in quality and quantity of renewable resources, can lead to increased environmental scarcity. This scarcity in turn, can lead to forced migration into ecologically-marginalized areas.

To illustrate his findings, Homer-Dixon highlighted the case of the Philippines, where in rural areas like the Negros, the primary method of farming has been slash and burn or swidden agriculture. Previously, with lower population densities, this method did little harm as the burned land had time to regenerate while other land was cultivated. With the rapid increase in population, however, both through natural increase and migration, the fallout from swidden agriculture has been fierce. The major environmental stresses have been erosion slides, flashfloods, washed out bridges and other structures, an increase in silt burdens, coral reef destruction, and fish stock depletion. In the case of the Philippines, the ecological problems have created a vicious cycle of migration both further and further upland and into the squatter settlements of large urban areas such as Manila. These migration flows appear to have fueled both urban unrest and rural insurgency.

While environmental scarcity is not a direct cause of violent conflict, it is important to understand that environmental scarcity in the context of other variables can be a contributing factor to violence. Homer-Dixon discussed different factors that can interrelate with environmental scarcity in causing violence. He listed four factors in each of two different categories. In a first category, the adaptability of a state's social structures included the stability of markets, autonomy of the state, the strength of social capital (e.g., norms, trust, reciprocity), and the strength of a social norm of responsibility for the greater good. The second category is tied to relations among groups: the strength of pre-existing ethnic divisions, a conception of justice by those challenging the government (as opposed to traditional peasant resignation or fatality), the resources and organizations of the challengers to the status quo, and the quality of leadership.

Discussion centered on what richer nations and institutions like the World Bank should do to resolve these issues as well as the abilities of societies to adapt to extreme social stress. Homer-Dixon ended the session by stressing that all of these dynamics do not happen in isolation of the global political economy. The environmental interactions are often undervalued but deserve more attention for the potential impact on political and violent conflict.