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Can changes to the climate increase conflict?

by Francesco Femia and Caitlin E. Werrell | Center for Climate and Security
Tuesday, 6 August 2013 10:15 GMT

* Any views expressed in this opinion piece are those of the author and not of Thomson Reuters Foundation.

Changes in the climate may make us more likely to honk a car horn, punch someone at a sports event, or even start a civil war

Changes in the climate may make us more likely to honk a car horn, punch someone at a sports event, or even start a civil war. That’s the conclusion of a new study released this week.

The study, published in Science, finds that abnormal temperature spikes, more extreme rainfall and other factors associated with climate change, can increase the likelihood of interpersonal and intergroup conflict ranging from domestic violence to war.

The study represents a review of 60 previous studies and 45 different conflict data sets. Though the study – by design – does not assess other sociological drivers (or mitigators) of conflict, it represents a starting point for further research and action.


In light of this study, the current historical context is worth repeating. We have entered a point in human history that is unprecedented in terms of the rate and scale of climatic change, human population, and economic acceleration.

No one can precisely foresee how climate change will influence human societies in the future – including how it will influence human conflict. History can tell us a lot, but we may need to look more and more to data-driven projections, such as the recent Intelligence Community Assessment on Global Water Security.

But though the study published this week assesses only brief departures from normal temperatures and rainfall in history, and does not account for societal factors that mitigate conflict, it still gives us some new information about the possible sensitivity of humans to climate stress, which offers important clues about mitigating future climate risks.

Another study published in the June issue of Nature, asserts that more research and more theory-building are needed regarding how climate change might affect conflict. This week’s study is a step in that direction, but just a step.

As with all fields of science, particularly those in the early stages of theoretical development, we do not yet have a complete picture of how climate change and conflict will interact. It is therefore important at this point not to overstate the study’s conclusion, which asserts that climate variability is just one factor among many drivers of conflict.

But let’s also not understate it unless we have significantly more research to suggest that the connection is insignificant. The old adage, “an absence of evidence is not an evidence of absence,” applies here. And in this case, studies are chipping away at the “absence of evidence” part, with statistically significant conclusions about the links between past climate variability and violence. They have given us some evidence. Now it is time to get to work and analyse it, test it, figure out how robust it is, build on – and add nuance to – its conclusions with additional research.


Before the ink was dry on this study, the media flared up with sensational headlines and debates about “environmental determinism,” which have tended to bury the actual data, methodology and conclusions of the study.

For example, the Science study states that violence linked to heat and drought “…might occur for a variety of reasons that simply become more likely when climatic conditions deteriorate.” But some public commentary has focused on the straw man that “climate change causes conflict,” which is not a conclusion of the study.

“Increases the likelihood of conflict” is the key concept. The actual top-line conclusion of the study is worth a look: “The magnitude of climate’s influence is substantial: for each one standard deviation change in climate toward warmer temperatures or more extreme rainfall, median estimates indicate that the frequency of interpersonal violence rises 4 percent and the frequency of intergroup conflict rises 14 percent. Because locations throughout the inhabited world are expected to warm 2 to 4 degrees by 2050, amplified rates of human conflict could represent a large and critical impact of anthropogenic climate change.”

Closer examination of this study should yield more thorough assessments. Lauren Morello’s write-up on the Nature news site is a good start, but it will take some time to get past the heat in the debate (pun intended).


However this particular study is judged in the future, it has certainly added to a growing evidence base, and policy-makers should take note. If there is a possibility that the risk of conflict increases due to climatic change, as a society we need to at least be prepared to deal with it. That is what risk management is all about.

A debate that ignores the data and analysis of risk in favor of media-driven ideas can be disastrous for the development of sound policy – particularly in terms of policies addressing national and international security.

As Andrew Holland at the American Security Project compellingly argues:  “For national security planners and professionals, we don’t need a scientific consensus directly linking past changes in climate or temperature to violent conflict. When national security planners look at threats to our security, they know that you cannot act with certainty: once you have 100 percent certainty, it is too late to act. The truth is that so long as there’s a persuasive chance that climate change will cause conflict, prudent actions to mitigate the threat are in order.”

We made a similar assertion in a piece published by the Bulletin of Atomic Scientists, arguing that in the overall U.S strategy, much lower degrees of certainty persist in the understanding of risks such as the detonation of weapons of mass destruction, international terrorist attacks, and systemic economic crises. And yet we devote significant attention and resources to addressing and preparing for those risks.

The possibility – which now seems more and more likely - that climate change can play a role in magnifying the likelihood of conflict should be treated in much the same way. We cannot wait until it is too late to develop smart policies to address it.

But “smart policies” is a key phrase here. As the authors of a recent Woodrow Wilson Center publication argued, it is important to avoid instituting policies that might heighten the possibility of conflict. The Thomas Midgley “Law of Unintended Consequences” comes to mind.


Though there is growing evidence that environmental and climatic factors can multiply other drivers of conflict (and thus increase its likelihood), this is not yet a feature of most conflict analyses. For example, the Failed State Index, a popular and oft-cited index for assessing “failed states,” which looks at conflict and conflict potential, does not, as of yet, incorporate climate variables – ones that can contribute to agricultural disruption, and forced migration.

That is what occurred in Syria from 2006-2011, a phenomenon that security analysts largely left out of assessments of Syria’s stability in the past. This suggests that the conflict literature has significant holes that need to be patched up if we are to better understand drivers of violence.

The Science study, though light on sociological context, can help feed into the development of more comprehensive conflict analysis and better risk assessment, which can, in turn, improve security from local to national to international levels.

More research must be done to test the linkages between temperature variance and the kind of human behavior that leads to conflict - and to determine the lines of causation.

But it is becoming increasingly clear that there is a scientifically sound probability that climatic changes can heighten the risk of conflict. That is enough certainty to suggest that our governments need to take the security risk of rapid and unprecedented climate change seriously. To quote retired U.S. Navy Rear Admiral David Titley, in regards to taking action on climate change:  “In the military, if you wait until you’re absolutely certain that you’re in grave danger, you’re already dead.”

Francesco Femia and Caitlin E. Werrell are founding directors of the Center for Climate and Security. This blog first appeared on the center website.