Armed-conflict risks enhanced by climate-related disasters in ethnically fractionalized countries
- aPotsdam Institute for Climate Impact Research, 14473 Potsdam, Germany;
- bClimate Analytics, 10969 Berlin, Germany;
- cIntegrative Research Institute on Transformations of Human–Environment Systems, Humboldt University, 10099 Berlin, Germany;
- dStockholm Resilience Centre, Stockholm University, 114 19 Stockholm, Sweden;
- eSanta Fe Institute, Santa Fe, NM 87501
See allHide authors and affiliations
Contributed by Hans Joachim Schellnhuber, May 20, 2016 (sent for review February 5, 2016; reviewed by Yoshito Hirata and Jürgen Scheffran)

Significance
Ethnic divides play a major role in many armed conflicts around the world and might serve as predetermined conflict lines following rapidly emerging societal tensions arising from disruptive events like natural disasters. We find evidence in global datasets that risk of armed-conflict outbreak is enhanced by climate-related disaster occurrence in ethnically fractionalized countries. Although we find no indications that environmental disasters directly trigger armed conflicts, our results imply that disasters might act as a threat multiplier in several of the world’s most conflict-prone regions.
Abstract
Social and political tensions keep on fueling armed conflicts around the world. Although each conflict is the result of an individual context-specific mixture of interconnected factors, ethnicity appears to play a prominent and almost ubiquitous role in many of them. This overall state of affairs is likely to be exacerbated by anthropogenic climate change and in particular climate-related natural disasters. Ethnic divides might serve as predetermined conflict lines in case of rapidly emerging societal tensions arising from disruptive events like natural disasters. Here, we hypothesize that climate-related disaster occurrence enhances armed-conflict outbreak risk in ethnically fractionalized countries. Using event coincidence analysis, we test this hypothesis based on data on armed-conflict outbreaks and climate-related natural disasters for the period 1980–2010. Globally, we find a coincidence rate of 9% regarding armed-conflict outbreak and disaster occurrence such as heat waves or droughts. Our analysis also reveals that, during the period in question, about 23% of conflict outbreaks in ethnically highly fractionalized countries robustly coincide with climatic calamities. Although we do not report evidence that climate-related disasters act as direct triggers of armed conflicts, the disruptive nature of these events seems to play out in ethnically fractionalized societies in a particularly tragic way. This observation has important implications for future security policies as several of the world’s most conflict-prone regions, including North and Central Africa as well as Central Asia, are both exceptionally vulnerable to anthropogenic climate change and characterized by deep ethnic divides.
Footnotes
- ↵1To whom correspondence may be addressed. Email: john{at}pik-potsdam.de or schleussner{at}pik-potsdam.de.
Author contributions: C.-F.S., J.F.D., R.V.D., and H.J.S. designed research; C.-F.S. performed research; C.-F.S. and J.F.D. analyzed data; and C.-F.S., J.F.D., R.V.D., and H.J.S. wrote the paper.
Reviewers: Y.H., Institute of Industrial Science, University of Tokyo; and J.S., University of Hamburg.
The authors declare no conflict of interest.
Data deposition: The data in this paper have been deposited at www.pik-potsdam.de/research/publications/pnas/Schleussner_et_al_2016_PNAS_scripts.zip.
This article contains supporting information online at www.pnas.org/lookup/suppl/doi:10.1073/pnas.1601611113/-/DCSupplemental.
Freely available online through the PNAS open access option.
Citation Manager Formats
Article Classifications
- Physical Sciences
- Environmental Sciences
- Social Sciences
- Sustainability Science














