A January special issue of the Journal of Peace Research brings together a new collection of evidence on a subject that has been a mainstay of the environmental security agenda: the links between climate and conflict.

Though the evidence for simple, especially direct, causal linkages between climate and conflict appears to be waning, there are still many questions to be asked and much to be learned about the potentially more complex interactions between shifts in the climate and existing sources of tension and strain.

Several studies delve deeply into the specific mechanisms that might link a shifting climate to an increased risk of conflict and find “limited support for viewing climate change as an important influence on armed conflict,” according to guest editor Nils Petter Gleditsch (see his post on the issue here).

The studies collected in the special issue offer an excellent glimpse at the state of the field for researchers and policymakers alike. We’ve collected a few comments on the issue here, from researchers Solomon Hsiang of Princeton University and Todd G. Smith of University of Texas, Austin, and will continue to post them as they come:

Solomon Hsiang, Princeton University

From a research standpoint, I think the largest contributions in the January special issue of the Journal of Peace Research on climate and conflict are the various new data sets that are being developed and introduced. It will take some time for the research community to carefully extract information from these new data sets, so the preliminary findings in this issue should be examined cautiously.

However, having carefully read all 16 papers in the issue, I think it is important to note that Nils Petter Gleditsch’s widely quoted statement from the abstract of his summary article – “overall, the research reported here offers only limited support for viewing climate change as an important influence on armed conflict” – does not accurately represent the findings presented in the special issue.

The issue contains 16 research articles, 8 of which are large sample studies capable of examining whether climate systematically influences the likelihood of conflict in various contexts (the others are theoretical, case studies or large sample studies examining other questions). Of these eight studies, seven (88 percent) find evidence that climate influences conflict (the one remaining study fails to find evidence that floods and intense storms do not generate conflict by slowing GDP growth, which is unsurprising).

Thus, overall, the data and findings in the special issue are consistent with the main result from the existing literature: Climatological changes have had substantial and measurable impacts on the likelihood of conflict.

Also consistent with existing results, these studies tend to find that the effect of climate on conflict appears to be the strongest in low income or weakly institutionalized populations, although neither these studies nor previous studies have been able to understand why these societies are particularly vulnerable. It is possible that…

1. These populations lack the resources or institutions necessary to adapt to climatological changes;
2. These populations are low income or weakly institutionalized because they experience climate-related conflict; or
3. They are low income, weakly institutionalized and prone to climate-related conflict for some additional, unobserved reason.

We still do not know.

Todd G. Smith, University of Texas

Nils Petter Gleditsch writes in the introductory article to this collection, “it seems fair to say that so far there is not yet much evidence for climate change as an important driver of conflict.” This grossly overstates the non-findings of a link between climate change, or weather factors, and conflict. In my view, all but a few of the authors find some connection between climate change and conflict – perhaps indirectly, in interaction with other factors, or in unexpected ways, but a connection nonetheless.

It is true that climate change is very unlikely by itself to cause resource scarcities that will directly lead to conflict, much less civil war, but conflict is rarely if ever caused by a single driver. No one claims, at least not anymore, that the relationship is simple.

If the typical story about climate change induced resource scarcities is increasingly dubious, researchers should – and indeed they have begun to, as evidenced by these articles – turn their attention to explaining other potential mechanisms, using both quantitative and qualitative methodologies.

This collection includes articles that investigate the connection between climate change and leading to conflict using different conflict outcome measures, in different contexts, and via different causal pathways. Types of conflict examined include civil war, local level communal conflict, and social unrest (i.e. strikes, riots, and demonstrations). The different contexts examined include pastoral areas of East Africa and the Sahel, international water basins, and post-disaster settings. And many of them begin to better unravel different causal pathways such as a climate disaster leading to conflict through reduced economic growth and through the interactions between poverty, civil war, and climate change. Finally, several articles focus on institutions as potential mediating factors, which is critical for policymakers because they can be the focus of effective interventions.

This is a good beginning but there is much work to be done. Many questions remain unanswered and many mechanisms remain unexplored. What is the mechanism behind the association between wet periods and conflict observed by several of the studies? Will climate change lead to changing migration patterns and, if so, is this a causal pathway to conflict? How might climate change fuel conflicts in urban settings? Is there potential for conflict over climate adaption funds or carbon financing?

These are just a few of the areas that deserve further investigation, and until conflict pathways are properly specified, it is futile to continue to search for a correlation between the beginning of the causal chain (climate or weather) and the end (conflict) without specifying the intermediate links. But it is equally disingenuous to deny some connection between climate change and conflict in light of this collection of mostly compelling articles.

The authors recognize the limitations, empirical or otherwise, of their research and all of them claim that further research is necessary. In so doing, they implicitly recognize that climate change is at least a potential driver of conflict. Otherwise the security literature could ignore it. Understanding the complexities behind these relationships is the first step to preventing the worst and realizing the best of the possible outcomes.