Study ties conflict risk in sub-Saharan Africa to climate change, socioeconomics, geography

The new research follows a 2012 PNAS study led by O’Loughlin that indicated the risk of human conflict in East Africa from 1990 to 2009 increased somewhat with hotter temperatures and dropped a bit with higher precipitation. That study, which charted about 26,000 instances of conflict, also showed socioeconomic, political and geographic factors played a larger role in armed conflicts than climate change.

For the new study the research team divided the African continent into thousands of geographic grid cells, each about 6,214 square miles (10,000 square kilometers), examining them individually for both conflict and climate data, said O’Loughlin, also a faculty research associate at CU-Boulder’s Institute of Behavioral Sciences.

O’Loughlin said the link between climate and violent conflict is strongest for “communal incidents” — violence between groups of civilians, rather than large-scale civil wars where rebel groups battle government armies.

The exhaustive database of violent events in the Sahel from 1980 to 2012 was assembled in part by CU-Boulder undergraduates, who combed online information sources like LexisNexis, a corporation that pioneered the electronic accessibility of legal and newspaper documents.

The work by the students — who put thousands of hours into the project — was funded by the NSF’s Research Experience for Undergraduates (REU) and has generated several undergraduate honors theses, O’Loughlin said.

The CU-Boulder students coded each conflict event with very specific data, including geographic location coordinates, dates, people and descriptive classifications. The event information was then aggregated into months and into the grid cells that served as the units of analysis for quantitative modeling.

Each conflict grid also was coded by socioeconomic and political characteristics like distance to an international border, capital city, local population size, well-being as measured by infant mortality, the extent of political rights, presidential election activity, road network density, vegetation condition and ethnic community inclusion into the national government. The National Center for Atmospheric Research in Boulder and the University of East Anglia in Norwich, England, provided climate data for the study.

Data also came from the Armed Conflict Location and Event Dataset (ACLED), directed by Clionadh Raleigh of Trinity College in Dublin.  That database covers individual conflicts from 1997 to 2009 in Africa and parts of Asia and Haiti. There are more than 60,000 violent incidents in the database to date. Raleigh started the data collection while earning her doctorate at CU in 2007 under O’Loughlin.

The release notes that as a next step, O’Loughlin has undertaken a new NSF-funded study with CU-Boulder anthropology Professor Terrence McCabe and political science Professor Jaroslav Tir to look at the mechanisms of conflict in Kenya. Researchers are interviewing Kenyans about their experiences regarding both violence and climate change, including the severity and frequency of drought. The study will include data on human migrations as well as the welfare of pastoralists and farmers as a result of climate change, he said.

— Read more in John O’Loughlin et al., “Effects of temperature and precipitation variability on the risk of violence in sub-Saharan Africa, 1980–2012,” Proceedings of the National Academy of Sciences (9 October 2014) (doi: 10.1073/pnas.1411899111); and John O’Loughlin et al., “Climate variability and conflict risk in East Africa, 1990–2009,” Proceedings of the National Academy of Sciences (11 September 2012) (doi: 10.1073/pnas.1205130109)