ratives and news reports of conflict over diminishing resources frequently concern clashes between rivaling ethnic groups or between pastoralists and sedentary farmers. The conflicts in Assam in India, Darfur in Sudan, Kenya, Mali, and Mauritania, all central cases in the environmental security literature, were at least initially interethnic conflicts without explicit state involvement. Key questions in this regard are how environmental conditions and rapid environmental change affect intercommunal relations and local land use disputes, and what role the state plays in ending or fueling these conflicts. (p. 106)
Because climate change has the potential for an increase in the number or severity of various types of disasters caused by weather-related extreme events (cyclones, storm surges, floods, droughts, wildfires, etc.) or geographic shifts, or at least an expansion of their areas of incidence, there has been a renewed interest in the possible link between such events and interstate and intrastate violence.13 Using a time series for 1966–1980, Drury and Olson (1998) provided the first quantitative attempt to test for a relationship between disasters and political instability and found “a direct and positive linkage between disaster severity and ensuing levels of political unrest” (p. 153). Ten years later Nel and Righarts (2008) analyzed a much larger number of cases (183 from the period 1950–2000) and found a positive and robust relationship between natural disasters of all types and both major (more than 1,000 killed) and minor (less than 1,000 killed) internal armed conflict occurring in the same year as the disaster as well as in the following year. Interestingly, when the analysis was limited to climate-type disasters only, there was only a correlation with major armed conflict, not minor. In a separate study that focused only on earthquakes, Brancati (2007) found a positive relationship between earthquakes and ensuing instances of political violence. The evidence indicates that climate events can contribute to social and political disruption in various ways, sometimes causing as much as a doubling of risks of adverse outcomes.
Recently, however, all of these findings and conclusions have been challenged by Omelicheva (2011), Bergholt and Lujala (2012), and Slettebak (2012), who question in different ways the previous studies’ variable specifications and measurements, particularly their inadequate inclusion of control variables in their models. On the whole, their arguments contend that when closer attention is paid to variable specification and measurement and the models are made more complex with closer attention to such things
13 A separate stream of literature not treated here on the role of disasters/catastrophes, including ENSO-related events, in what might be called civilizational collapses or macro-system changes would include Davis (2002), Diamond (2005), Nur and Burgess (2008), Fagan (2009), and Johnson (2011) among others.