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Does Climate Change Cause Armed Conflict?

climate conflict pic nature


A new study finds that climate has affected the risk of armed conflict to date. Though other drivers of violence were found to be substantially more influential, as global temperatures continue to rise, the changing climate is expected to further amplify the risk of conflict.

By Devon Ryan, Stanford Woods Institute for the Environment

Can a changing climate trigger organized armed conflict, such as civil war, or make it more severe?

A study published today in the journal Nature endeavors to explain the current state of debate on the issue through consultation with experts in fields such as political science, environmental science and economics, who hold divergent views. The experts' best estimates are that 3 to 20 percent of the risk of violent armed conflict within countries has been influenced by climate over the last century. None of the experts, who also serve as co-authors of the study, ruled out the role of climate in 10 percent of conflict risk.

"Disagreement on climate and conflict has been stark," said Katharine Mach, Director of the Stanford Environment Assessment Facility and study lead author. "Our analysis represents a strong foundation for figuring out the strengths and limitations of current understanding and reasons for disagreement."

In a scenario with 4 degrees of warming (approximately the path we're on now if societies do not substantially reduce emissions of heat-trapping gases), the influence of climate on conflicts increases more than 5 times, leaping to 26 percent chance of a substantial increase in conflict risk, according to the study. Even in a scenario of 2 degrees Celsius of warming beyond preindustrial levels–the stated goal level of the Paris Climate Agreement¬–the influence of climate on conflicts would more than double, rising to 13 percent chance.

Climate change can impact agricultural production, economies, and even inequities among groups, all of which can interact with other conflict drivers and potentially increase risks of violence.

"With so much at stake in the debate over the security implications of climate change, it's refreshing to have a consensus statement that leverages so much international expertise—and an honor to have been able to help," said Cullen Hendrix, Director of the Sié Chéou-Kang Center for International Security and Diplomacy at the Josef Korbel School and a co-author on the study. "Climate change will present a host of challenges to economic, social, and political systems the world over—up to and including heightening the risk of armed conflicts that would threaten the security of millions."

While the experts agree that climate has affected organized armed conflict in recent decades, they make clear that other factors, such as low socioeconomic development, the strength of government, inequalities in societies, and a recent history of violent conflict, have a much heavier impact on conflict within countries.

Uncertainty about climate change's effect on armed conflict remains. In particular, the mechanisms through which climate affects conflict and under what conditions those mechanisms materialize are only partially understood. For example, consequences of future climate change will likely be different from historical climate disruptions.

"Historically, levels of armed conflict over time have been heavily influenced by shocks to, and changes in, international relations among states and in their domestic political systems," said James Fearon, professor of political science and co-author on the study. "It is quite likely that over this century, unprecedented climate change is going to have significant impacts on both, but it is extremely hard to anticipate whether the political changes related to climate change will have big effects on armed conflict in turn. So I think putting non-trivial weight on significant climate effects on conflict is reasonable."

Reducing conflict risk and preparing for a changing climate can be a win–win approach. The study explains that adaptation strategies, such as crop insurance, postharvest storage, training services, and other measures, can increase food security and diversify economic opportunities thereby reducing potential climate–conflict linkages. Peacekeeping, conflict mediation and post-conflict aid operations could incorporate climate into their risk reduction strategies by looking at ways climatic hazards may exacerbate violent conflict in the future.

However, the researchers make clear there is a need to increase understanding of the strategies' effectiveness and potential for adverse side effects. For example, food export bans following crop failures can increase instability elsewhere.

"One of the major challenges of dealing with climate change is that adaptive strategies themselves carry potential threats. Global food markets have increased human wellbeing considerably, but they make it easier for a drought in Russia to translate into food-related protests in the Midde East," said Hendrix. "Moving forward, we will need to think creatively in order to harness the global economy for promoting the greater good and addressing climate change."


Stanford Author Affiliations:

Mach is also a senior research scientist in Earth system science. Burke is a center fellow at the Freeman Spogli Institute for International Studies and, by courtesy, at the Stanford Woods Institute for the Environment. Fearon is the Theodore and Frances Geballe Professor in the School of Humanities and Sciences; a senior fellow at the Freeman Spogli Institute for International Studies; and professor, by courtesy, of economics.

Other Stanford co-authors include: Chris Field, the Melvin and Joan Lane professor for Interdisciplinary Environmental Studies, a professor of biology and of Earth system science, Perry L. McCarty director of the Stanford Woods Institute for the Environment, and a senior fellow at the Precourt Institute for Energy; Kenneth Schultz, professor of political science; and Caroline Kraan, research professional at the Stanford Woods Institute for the Environment and the Stanford Environment Assessment Facility.

DU Author Affiliations:

Hendrix is Professor and Director of the Sié Chéou-Kang Center for International Security and Diplomacy at the Josef Korbel School of International Studies.

Stanford Media Contacts:

Katharine Mach, Department of Earth System Science
(650) 561-5640

Devon Ryan, Stanford Woods Institute for the Environment
(650) 497-0444

DU Media Contacts:

Kate Morgan, Sié Center for International Security and Diplomacy
(303) 871-7713