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

A new study in the journal Nature, co-authored by Lancaster University’s Dr Jean-Francois Maystadt, 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.

“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.”

The experts’ best estimates are that 3 to 20 per cent of the risk of violent armed conflict within countries has been influenced by climate over the last century. None of the experts, who serve as co-authors of the study, ruled out the role of climate in 10 percent of conflict risk.

“Most striking to me is the consensus among scholars from different disciplines who have reached very different conclusions about the climate-conflict nexus in their previous work,” said Dr Maystadt, of the Institute of Development Policy (Antwerp University) and Lancaster University’s Department of Economics.

“Climate is recognised to have affected organised armed conflict in recent decades. However, even among those, like me, who found a strong role of climatic variations in explaining conflict, there is a wide acknowledgement that other drivers, like low socioeconomic development, low state capacity, intergroup inequality, and a recent history of violent conflict, have a heavier impact on conflict within countries. But climate change is also estimated to increase future conflict risk.”

In a scenario with 4C degrees of warming (approximately the path we are on now if societies do not substantially reduce emissions of heat-trapping gases), the influence of climate on conflicts increases more than five times, leaping to a 26 per cent chance of a substantial increase in conflict risk, according to the study. Even in a scenario of 2C 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 a 13 per cent 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.

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 materialise 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 economic shocks, the presence of natural resources, in particular in highly polarised and institutionally weak societies,” added Maystadt, a development economist specialising in the study of conflict, natural disasters and forced migration. “Changes in international relations among states have also played a significant role.

“It is quite likely that over this century, unprecedented climate change is going to affect the risk of conflict through these channels and others, but it is extremely hard to quantify and predict. What this study has shown me is that we need to work across disciplines to overcome the analytical challenges identified in the study and support effective risk management as the climate continues to change.”

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, post-harvest storage, training services and other measures, can increase food security and diversify economic opportunities, thereby reducing potential climate-conflict links. 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.

“Appreciating the role of climate change and its security impacts is important not only for understanding the social costs of our continuing heat-trapping emissions, but for prioritising responses, which could include aid and cooperation,” added Mach.