Demonstrators participate in a silent protest in front of a conference hall where the Intergovernmental Panel on Climate Change was meeting in Yokohama, near Tokyo, on March 31. (Shizuo Kambayashi/AP)

Joshua Busby is an associate professor at the LBJ School of Public Affairs at the University of Texas-Austin and one of the leading researchers involved in the Climate Change and African Political Stability (CCAPS) program, a five-year grant funded by the U.S. Department of Defense under its Minerva Initiative.

The Intergovernmental Panel on Climate Change (IPCC) just released the Working Group II report from its Fifth Assessment, summarizing the scientific community’s latest findings on climate change impacts around the world. For the first time, the IPCC includes a chapter on human security. The media immediately highlighted the connections between climate change and conflict. The IPCC is going beyond the physical sciences to examine how climate change affects society and politics.

However, the care that the authors took in describing the state of scientific knowledge about violence and conflict may get lost. As scientific claims go public, they often lose their nuances.

The chapter on human security examines not only climate and conflict, but how climate change can affect migration, vulnerable populations and more. The section on climate and conflict focuses on intrastate conflict, civil wars and communal violence. Because researchers often disagree about how or whether climate change sometimes causes violence, the IPCC report is necessarily cautious:

Some of the factors that increase the risk of violent conflict within states are sensitive to climate change (medium agreement, medium evidence). The evidence on the effect of climate change and variability on violence is contested. Although there is little agreement about direct causality, low per capita incomes, economic contraction, and inconsistent state institutions are associated with the incidence of violence.

However, the summary for policymakers, (where each line is reviewed by governments, as best as I understand it) is rather more forward leaning:

Climate change can indirectly increase risks of violent conflicts in the form of civil war and inter-group violence by amplifying well-documented drivers of these conflicts such as poverty and economic shocks (medium confidence).

Journalists may erode the nuance and subtleties still further, for example by not mentioning that the report only has medium confidence that there is a relationship between climate change and violent conflict.

The indirect pathways between climate change and violence identified by the report have barely been tested by scholars. Most of the important work in this space (including work by my colleagues Cullen Hendrix, Idean Salehyan, and Clionadh Raleigh) looks at the direct linkages between climate change and violence.  Academics usually look for some analogue for the expected effects of climate change (e.g. droughts or rainfall change) and ask whether or not these historically have been associated with civil war, communal conflict, or strikes and riots. They don’t come to any strong agreement, and their results depend on which hazard they are looking at (i.e. too much rain or too little rain) as well as the kind of conflict (with the drivers of civil wars perhaps being different from communal conflict).

Statistically inclined scholars have had big arguments about whether climate change causes conflict (there have been some epic exchanges between Halvard Buhaug and Solomon Hsiang), but the most important debates are really about the causal mechanisms – i.e. the specific ways in which one thing ‘causes’ another – that connect climate hazards to conflict. Only recently have people started to look at the indirect (and possibly more plausible) pathways by which climate change might lead to conflict such as through economic growth (see Koubi et al.) and food price shocks (see Smith).

As I have argued before, getting hung up on whether and how climate causes conflict misses other important security consequences associated with climate change. Climate-related hazards already expose millions to the risk of mass death from extreme weather events, and those risks will likely become worse with climate change.

As the new IPCC report notes, climate vulnerability is not distributed equally around the world, with developing countries and marginalized populations within them most vulnerable given limited coping capacity. Even within Africa, the continent thought most vulnerable to climate change, our work shows that some locations are more vulnerable than others, given variation in local physical exposure, population density, community resources, and governance. These vulnerabilities and what we already know about climate change provide compelling reasons to act.

Map of vulnerability in Africa

Hot Spot Map of Climate Security Vulnerability in Africa