Frank D. W. Witmer

Climate variability and conflict risk in East Africa, 1990–2009

Recent studies concerning the possible relationship between climate trends and the risks of violent conflict have yielded contradictory results, partly because of choices of conflict measures and modeling design. In this study, we examine climate–conflict relationships using a geographically disaggregated approach. We consider the effects of climate change to be both local and national in character, and we use a conflict database that contains 16,359 individual geolocated violent events for East Africa from 1990 to 2009. Unlike previous studies that relied exclusively on political and economic controls, we analyze the many geographical factors that have been shown to be important in understanding the distribution and causes of violence while also considering yearly and country fixed effects. For our main climate indicators at gridded 1° resolution (∼100 km), wetter deviations from the precipitation norms decrease the risk of violence, whereas drier and normal periods show no effects. The relationship between temperature and conflict shows that much warmer than normal temperatures raise the risk of violence, whereas average and cooler temperatures have no effect. These precipitation and temperature effects are statistically significant but have modest influence in terms of predictive power in a model with political, economic, and physical geographic predictors. Large variations in the climate–conflict relationships are evident between the nine countries of the study region and across time periods.

The Localized Geographies of Violence in the North Caucasus of Russia, 1999–2007

The second Chechen war, starting in the North Caucasus in August 1999, shows few signs of a ceasefire after eleven years, although the level of violence has declined from the peaks of the wars first two years. Initially framed by both sides as a war of separatists versus the federal center, the situation is now complicated by the installation of a Moscow ally into power in Chechnya and by the splintering of the opposition into groups with diverse aims and theaters of operation. The main rebel movement has declared the establishment of an Islamic caliphate in all the Muslim republics of the North Caucasus as its ultimate goal. Fears of regional destabilization of the entire North Caucasus of Russia are propelled by reports of increased militant activism in republics adjoining Chechnya due to possible contagion effects of violence in these poor areas. Temporal and spatial descriptive statistics of a large database of 14,177 violent events, geocoded by precise location, from August 1999 to August 2007, provide evidence of the conflicts diffusion into the republics bordering Chechnya. “Hot spots” of violence are identified using Kulldorffs SaTScan statistics. A geographically weighted regression predictive model of violence indicates that locations in Chechnya and forested areas have more violence, whereas areas with high Russian populations and communities geographically removed from the main federal highway through the region see less violence.

Detecting the Effects of Wars in the Caucasus Regions of Russia and Georgia Using Radiometrically Normalized DMSP-OLS Nighttime Lights Imagery

Satellite data can provide a remote view of developments in often dangerous conflict zones. Nighttime lights imagery from the Defense Meteorological Satellite Program (DMSP) Operational Linescan System (DMSP-OLS) satellite was used to detect the effects of war in the Caucasus region of Russia and Georgia. To assess changes over time, the data were radiometrically normalized using cities with a relatively stable nighttime lights signature over the course of the study period, 1992-2009. Buffers were created around these stable cities to select the pixels that were then used to normalize cities and towns whose nighttime lighting fluctuated over time. The results show that conflict-related events such as large fires that burn for weeks and large refugee movements are possible to detect, even given the relatively coarse spatial resolution (2.7 km) of the DMSP-OLS imagery.

The Afghanistan-Pakistan Wars, 2008-2009: Micro-geographies, Conflict Diffusion, and Clusters of Violence

A team of political geographers analyzes over 5,000 violent events collected from media reports for the Afghanistan and Pakistan conflicts during 2008 and 2009. The violent events are geocoded to precise locations and the authors employ an exploratory spatial data analysis approach to examine the recent dynamics of the wars. By mapping the violence and examining its temporal dimensions, the authors explain its diffusion from traditional foci along the border between the two countries. While violence is still overwhelmingly concentrated in the Pashtun regions in both countries, recent policy shifts by the American and Pakistani governments in the conduct of the war are reflected in a sizeable increase in overall violence and its geographic spread to key cities. The authors identify and map the clusters (hotspots) of conflict where the violence is significantly higher than expected and examine their shifts over the two-year period. Special attention is paid to the targeting strategy of drone missile strikes and the increase in their number and geographic extent by the Obama administration.

Effects of temperature and precipitation variability on the risk of violence in sub-Saharan Africa, 1980–2012

Significance A robust debate about the effects of climate change on conflict occurrences has attained wide public and policy attention, with sub-Saharan Africa generally viewed as most susceptible to increased conflict risk. Using a new disaggregated dataset of violence and climate anomaly measures (temperature and precipitation variations from normal) for sub-Saharan Africa 1980–2012, we consider political, economic, and geographic factors, not only climate metrics, in assessing the chances of increased violence. The location and timing of violence are influenced less by climate anomalies than by key political, economic, and geographic factors. Overall, the temperature effect is statistically significant, but important inconsistencies in the relationship between temperature extremes and conflict are evident in more nuanced relationships than have been previously identified. Ongoing debates in the academic community and in the public policy arena continue without clear resolution about the significance of global climate change for the risk of increased conflict. Sub-Saharan Africa is generally agreed to be the region most vulnerable to such climate impacts. Using a large database of conflict events and detailed climatological data covering the period 1980–2012, we apply a multilevel modeling technique that allows for a more nuanced understanding of a climate–conflict link than has been seen heretofore. In the aggregate, high temperature extremes are associated with more conflict; however, different types of conflict and different subregions do not show consistent relationship with temperature deviations. Precipitation deviations, both high and low, are generally not significant. The location and timing of violence are influenced less by climate anomalies (temperature or precipitation variations from normal) than by key political, economic, and geographic factors. We find important distinctions in the relationship between temperature extremes and conflict by using multiple methods of analysis and by exploiting our time-series cross-sectional dataset for disaggregated analyses.

Space-Time Granger Analysis of the War in Iraq: A Study of Coalition and Insurgent Action-Reaction

We investigate insurgent-coalition interaction using the WikiLeaks dataset of Iraq war logs 2004–2009. After a review of existing theoretical interventions on the dynamics of insurgency and presenting a baseline model of violent events, we test a conceptual model of reciprocity using an innovative space-time Granger causality technique. Our estimation procedure retains predicted probabilities of reaction in response to a previous opponents action across different temporal and spatial configurations in Iraq and in Baghdad. Our conclusions about conflict in Iraq are based on these profiles of risk—what we call space-time signatures. We find strong evidence of “tit-for-tat” associations between coalition/Iraq forces on one side and insurgents/militants on the other. Specifically, we find that the action-reaction association varies strongly by majority ethnic region across Iraq and in Baghdad, by urban and nonurban location, and within Sunni-dominated areas, by district income. While violence is strongly temporally dependent in the same location, the effect of distance varies significantly across the different subsets of the Iraq data.

Satellite Data Methods and Application in the Evaluation of War Outcomes: Abandoned Agricultural Land in Bosnia-Herzegovina After the 1992–1995 Conflict

The devastation of wars is most often measured in terms of the number of dead and missing people, but other conflict effects are long-lasting and far-reaching. The 1992–1995 war in Bosnia-Herzegovina resulted in almost 100,000 killed and almost half of the population displaced. This article analyzes the wars effects by evaluating impacts on the postwar agriculture environment from which most Bosnians derive their livelihoods. The wars impacts showed significant geographic variability, with localities near the frontlines and in eastern Bosnia-Herzegovina particularly affected. Thirty-meter Landsat imagery from before, during, and after the war was used to identify abandoned agricultural land in two study areas (northeast and south) within Bosnia-Herzegovina, characterized by different climates, soil, and vegetation. In the image analysis methodology, multiple change detection techniques were tested, and ultimately a supervised classification was chosen. Ground reference data collected during the spring seasons of 2006 and 2007 show the remote sensing methodology is effective in identifying abandoned agricultural land for the northeast study region but not for the southern one. The differential success rates were due primarily to variations in climate and soil conditions between the two regions, but also point to contrasts due to the different nature of the war in the two study regions. The study has important implications for the use of remote sensing data in tracking the course of conflicts and evaluating their long-term impacts.

Modeling and data choices sway conclusions about climate-conflict links

In an era of growing concern about the human impacts of climate change, the academic and policy communities are paying increasing attention to the possible link between weather anomalies and violent conflict. Early research papers on the topic by Burke et al. (1) and the reanalysis and extension of their work by Buhaug (2) claim contradictory findings, the first showing a link between increased temperatures and war, and the second—using an expanded dataset and different models—calling these results into question. Hsiang and Meng (3) reexamine the data and argue that the original Burke et al. (1) conclusions are robust and remain a “benchmark” for future studies of the climate–conflict relationship.

The Changing Geography of Violence in Russia's North Caucasus, 1999-2011: Regional Trends and Local Dynamics in Dagestan, Ingushetia, and Kabardino-Balkaria

Three U.S. geographers analyze the temporal and spatial trends of 17,438 violent events in Russias North Caucasus region from August 1999 to July 2011, demonstrating that the diffusion of conflict away from Chechnya intensified during the period 2007-2011, as levels of violence rose in neighboring republics. An increasing number of casualties are civilians in Dagestan, Ingushetia, and Kabardino-Balkaria, the three republics that are the focus of the paper. Employing multiple methods of spatial pattern analysis and geographically sensitive regression models, the authors examine the spatial fragmentation of violence from the perspective of rebel groups operating in the three republics. The analysis documents how the incidence of violence varies dramatically over space (i.e., reflecting the influence of urbanization, strategic location, and physical geographic factors such as elevation and extent of forest cover). Although violence in the North Caucasus region as a whole has declined in absolute terms over the past four years, the authors show how new geographies of violence are developing in the region, underscoring the emergence of republic-based insurgent operations against the various organs of the Russian state. Journal of Economic Literature, Classification Numbers: H560, H770, O180. 9 figures, 3 tables, 1 appendix, 103 references:

Remote sensing of violent conflict: eyes from above

The use of remote-sensing technology to study violent conflict has increased considerably over the last 5–10 years. This article surveys this growing field to show which conflict-related impacts are and are not currently possible to detect from afar. A brief overview of the principles of remote-sensing technology and sensor characteristics is provided, followed by a review and discussion of the literature, organized by temporal delay in the visible manifestation of the conflict impact from minutes for structural damage to years for changes to land use/land cover. Remote-sensing technology is most valuable in hard-to-reach and/or dangerous conflict zones where field observations are spotty or non-existent. Although good ground reference data are important for verifying the accuracy of observations derived from remote-sensing imagery, it is possible to corroborate or refute suspect reports with appropriate imagery and analysis techniques.