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Sampling bias in climate–conflict research

Abstract

Critics have argued that the evidence of an association between climate change and conflict is flawed because the research relies on a dependent variable sampling strategy1,2,3,4. Similarly, it has been hypothesized that convenience of access biases the sample of cases studied (the ‘streetlight effect’5). This also gives rise to claims that the climate–conflict literature stigmatizes some places as being more ‘naturally’ violent6,7,8. Yet there has been no proof of such sampling patterns. Here we test whether climate–conflict research is based on such a biased sample through a systematic review of the literature. We demonstrate that research on climate change and violent conflict suffers from a streetlight effect. Further, studies which focus on a small number of cases in particular are strongly informed by cases where there has been conflict, do not sample on the independent variables (climate impact or risk), and hence tend to find some association between these two variables. These biases mean that research on climate change and conflict primarily focuses on a few accessible regions, overstates the links between both phenomena and cannot explain peaceful outcomes from climate change. This could result in maladaptive responses in those places that are stigmatized as being inherently more prone to climate-induced violence.

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Fig. 1: Frequency of mentions of continents in the climate–conflict literature per year.
Fig. 2: Changes in the frequency of mentions in the climate–conflict literature depending on country characteristics.

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References

  1. Buhaug, H. et al. One effect to rule them all? A comment on climate and conflict. Climatic Change 127, 391–397 (2014).

    Article  Google Scholar 

  2. Buhaug, H. Climate–conflict research: some reflections on the way forward. WIREs Clim. Change 6, 269–275 (2015).

    Article  Google Scholar 

  3. Gemenne, F., Barnett, J., Adger, W. N. & Dabelko, G. Climate and security: evidence, emerging risks, and a new agenda. Climatic Change 123, 1–9 (2014).

    Article  Google Scholar 

  4. Raleigh, C., Linke, A. & O´Loughlin, J. Extreme temperatures and violence. Nat. Clim. Change 4, 76–77 (2014).

    Article  Google Scholar 

  5. Hendrix, C. S. The streetlight effect in climate change research on Africa. Glob. Environ. Change 43, 137–147 (2017).

    Article  Google Scholar 

  6. Barnett, J. The price of peace (is eternal vigilance): a cautionary editorial essay on climate geopolitics. Climatic Change 96, 1–6 (2009).

    Article  Google Scholar 

  7. Ide, T. Critical geopolitics and school textbooks: the case of environment–conflict links in Germany. Polit. Geogr. 55, 61–70 (2016).

  8. Verhoeven, H. Gardens of Eden or Hearts of Darkness? The genealogy of discourses on environmental insecurity and climate wars in Africa. Geopolitics 19, 784–805 (2014).

    Article  Google Scholar 

  9. McDonald, M. Discourses of climate security. Polit. Geogr. 33, 42–51 (2013).

    Article  Google Scholar 

  10. Ide, T. Research methods for exploring the links between climate change and conflict. WIREs Clim. Change 8, 1–14 (2017).

    Article  Google Scholar 

  11. O’Loughlin, J., Linke, A. M. & Witmer, F. D. W. Modeling and data choices sway conclusions about climate–conflict links. Proc. Natl Acad. Sci. USA 111, 2054–2055 (2014).

  12. Hsiang, S., Burke, M. & Miguel, E. Quantifying the influence of climate on human conflict. Science 341, 1–14 (2013).

    Article  Google Scholar 

  13. Hsiang, S. & Burke, M. Climate, conflict, and social stability: what does the evidence say? Climatic Change 123, 39–55 (2014).

    Article  Google Scholar 

  14. Kelley, C. P., Mohtadib, S., Cane, M. A., Seager, R. & Kushnir, Y. Climate change in the Fertile Crescent and implications of the recent Syrian drought. Proc. Natl Acad. Sci. USA 112, 3241–3246 (2015).

    Article  CAS  Google Scholar 

  15. De Juan, A. Long-term environmental change and geographical patterns of violence in Darfur, 2003–2005. Polit. Geogr. 45, 22–33 (2015).

  16. Feitelson, E. & Tubi, A. A main driver or an intermediate variable? Climate change, water and security in the Middle East. Glob. Environ. Change 44, 39–48 (2017).

    Article  Google Scholar 

  17. Hartmann, B. Rethinking climate refugees and climate conflict: rhetoric, reality and the politics of policy discourse. J. Int. Dev. 22, 233–246 (2010).

  18. Dalby, S. Recontextualising violence, power and nature: the next twenty years of critical geopolitics? Polit. Geogr. 29, 280–288 (2010).

    Article  Google Scholar 

  19. Ford, J. D., Berrang-Ford, L. & Paterson, J. A systematic review of observed climate change adaptation in developed nations. Climatic Change 106, 327–336 (2011).

    Article  Google Scholar 

  20. Downes, B. J., Miller, F., Barnett, J., Glaister, A. & Ellemor, H. How do we know about resilience? An analysis of empirical research on resilience, and implications for interdisciplinary praxis. Environ. Res. Lett. 8, 1–9 (2013).

    Article  Google Scholar 

  21. IPCC Climate Change 2014: Impacts, Adaptation, and Vulnerability (eds Field, C. B. et al.) (Cambridge Univ. Press, 2014).

  22. Melander, E., Pettersson, T. & Themnér, L. Organized violence, 1989–2015. J. Peace Res. 53, 727–742 (2016).

    Article  Google Scholar 

  23. Country Index Exposure 2015 (ND-GAIN, 2016); http://index.gain.org/ranking/vulnerability/exposure

  24. Kreft, S., Ecksetin, D. & Melchior, I. Global Climate Risk Index 2017 (Germanwatch, 2017).

  25. Benjaminsen, T., Alinon, K., Buhaug, H. & Buseth, J. T. Does climate change drive land-use conflict in the Sahel? J. Peace Res. 49, 97–111 (2012).

    Article  Google Scholar 

  26. Bernauer, T. & Gleditsch, N. P. New event data in conflict research. Int. Interact. 38, 375–381 (2012).

    Article  Google Scholar 

  27. Expanding research views. Nat. Clim. Change 7, 229 (2017).

  28. Gleditsch, N. P. Armed conflict and the environment: a critique of the literature. J. Peace Res. 35, 381–400 (1998).

    Article  Google Scholar 

  29. Adano, W., Dietz, T., Witsenburg, K. M. & Zaal, F. Climate change, violent conflict and local institutions in Kenya’s dryland. J. Peace Res. 49, 65–80 (2012).

    Article  Google Scholar 

  30. Fincher, R., Barnett, J. & Graham, S. Temporalities in adaptation to sea-level rise. Ann. Assoc. Am. Geogr. 105, 263–273 (2015).

    Article  Google Scholar 

  31. Higgins, J. P. T. & Green, S. (eds) Cochrane Handbook for Systematic Reviews of Interventions version 5.1.0 (Cochrane Collaboration, London, 2011).

  32. Ford, J. D. & Pearce, T. What we know, do not know, and need to know about climate change vulnerability in the western Canadian Arctic: a systematic literature review. Environ. Res. Lett. 5, 1–9 (2010).

    Article  Google Scholar 

  33. Zhang, D. D. et al. The causality analysis of climate change and large-scale human crisis. Proc. Natl Acad. Sci. USA 108, 17296–17301 (2011).

    Article  CAS  Google Scholar 

  34. Scheffran, J., Ide, T. & Schilling, J. Violent climate or climate of violence? Concepts and relations with focus on Kenya and Sudan. Int. J. Human. Rights 18, 366–387 (2014).

    Article  Google Scholar 

  35. Maystadt, J. F. & Ecker, O. Extreme weather and civil war: does drought fuel conflict in Somalia through livestock price shocks? Am. J. Agric. Econ. 96, 1157–1182 (2014).

    Article  Google Scholar 

  36. Theisen, O. M. Climate clashes? Weather variability, land pressure, and organized violence in Kenya, 1989-2004. J. Peace Res. 49, 81–96 (2012).

    Article  Google Scholar 

  37. Nardulli, P. F., Peyton, B. & Bajjalieh, J. Climate change and civil unrest: the impact of rapid-onset disasters. J. Confl. Resolut. 59, 310–335 (2015).

    Article  Google Scholar 

  38. Selby, J. Positivist climate conflict research: a critique. Geopolitics 19, 829–856 (2014).

    Article  Google Scholar 

  39. Hartmann, B. Converging on disaster: climate security and the malthusian anticipatory regime for Africa. Geopolitics 19, 757–783 (2014).

    Article  Google Scholar 

  40. Salehyan, I. Climate change and conflict: making sense of disparate findings. Polit. Geogr. 43, 1–5 (2014).

    Article  Google Scholar 

  41. World Populations Prospects: The 2017 Revision (United Nations, 2017).

  42. Employment in Agriculture (% of Total Employment) (International Labour Organization, 2017); https://data.worldbank.org/indicator/SL.AGR.EMPL.ZS?locations=AL

  43. World Development Indicators: Contribution of the Agricultural Sector to GDP (World Bank, 2017); https://data.worldbank.org/data-catalog/world-development-indicators

  44. Ide, T. et al. On exposure, vulnerability and violence: spatial distribution of risk factors for climate change and violent conflict across Kenya and Uganda. Polit. Geogr. 43, 68–81 (2014).

    Article  Google Scholar 

Download references

Acknowledgements

This research was completed with support from the Australian–American Fulbright Commission, the German Research Foundation (DFG) project ID80/2-1 and the Australian Research Council project FT120100208.

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Contributions

C.A., T.I., J.B. and A.D. designed the research, analysed the results and wrote the paper. C.A. performed the systematic literature review. A.D. and T.I. conducted the statistical analysis.

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Correspondence to Tobias Ide.

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The authors declare no competing financial interests.

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Supplementary Information

Supplementary Tables 1–3 and Supplementary Datasets 1–2

Supplementary Dataset 3

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Adams, C., Ide, T., Barnett, J. et al. Sampling bias in climate–conflict research. Nature Clim Change 8, 200–203 (2018). https://doi.org/10.1038/s41558-018-0068-2

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