In the Heat of the Moment

By Sara S. Moore

Many of us are versed in the primary hazards of climate change – from the cost of disasters in lives and resources to the disappearance of low-lying island nations. Something we hear about less often is the direct influence of climate on human behavior, and the implications for the future under climate change.

Climate change and civil conflict

Academics have only been putting the climate change-conflict link to close examination for about five years. Solomon Hsiang (UC Berkeley), Marshall Burke (Stanford), and Edward (Ted) Miguel (UC Berkeley) are pioneers in this field. Last year they unveiled the results of an analysis of 60 studies using 45 data sets from all regions of the world showing a correlation between heat, rain, and conflict. Last month they released a refinement of this study. In their working paper “Climate and Conflict” (summary here) they show significant increases in both interpersonal and intergroup conflicts (e.g., fist fights and wars) with greater heat and more extreme rainfall.

Some of the background studies cited by these researchers include a 2011 study that shows major league baseball pitchers are more likely to retaliate for their teammates being hit by the rival pitcher when it’s hotter. In their talk “Quantifying the Impact of Climate on Human Conflict” at UC Berkeley in April 2013, Miguel and Burke described fascinating experimental psychology studies showing that police are more likely to shoot at a simulated intruder in higher temperature rooms, and people are faster to lean on their horns behind a car stopped at a green light on hotter days.

Climate change and crime

In February of this year a journal article by Matthew Ranson described a correlation between crime and weather and speculated on the potential impact of climate change on crime. The author looked at 2,997 U.S. counties’ monthly crime and weather data over 30 years. He looked at FBI statistics for murder, manslaughter, rape, aggravated and simple assault, robbery, burglary, larceny, and vehicle theft. He states bluntly, “[a]cross a variety of offenses, higher temperatures cause more crime.” His rich data set appears to have established a strong link between heat and violent crime. Specifically, he shows a linear relationship between heat and violent crime and a nonlinear relationship with non-violent crime (property crime, e.g., burglary): he doesn’t see heat affecting property crime in any consistent way. Heat specifically exacerbates violence.

Measuring vulnerability to climate-related violence

Some analysts are trying to map out the world’s general vulnerability to climate-related violence. On Oct. 29, 2014, the 2015 “Climate Change and Environmental Risk Atlas” was released, naming 32 “extreme risk” countries where climate change might increase violence. Bangladesh was named most at risk. The author of the report, UK-based Maplecroft Global Risk Analytics, has produced this atlas annually since 2008. In 2011, its report included results of an analysis of 42 factors using the Climate Change Vulnerability Index (CCVI), intended to help corporations and governments identify vulnerabilities in their operations, supply chains, and investments. (Note: it is not to be confused with the tool of the same name launched by the Nature Conservancy in 2009 to evaluate wild species’ vulnerability.) Maplecroft’s tool incorporates social, economic, and environmental factors to assess vulnerability both at a national level and down to a resolution of 22km², looking 30 years out (as described in the 2014 Risk Atlas).

Over recent years other indices of vulnerability have been created (check out an annotated list of indices of climate change vulnerability from Other institutions have taken other approaches to identifying climate-driven violence risks.

The Pentagon and the Institute of Peace agree: climate change is bad for peace

As reported by James West in Mother Jones, the U.S. Department of Defense (in its 20-page adaptation roadmap released Oct. 13, 2014) and the U.S. Institute of Peace (in a 2011 report on Nigeria) are both worrying about weak governments, already fostering terrorism, being further weakened by impacts from climate change. While lacking adaptation policy recommendations, both institutions clearly and concisely describe the “threat multiplier” facet of climate change.

What can we do?

People developing climate impact response plans in the security, defense, and risk management fields should take into account the results of recent studies linking climate change and conflict. Extreme climate events can be tracked and direct and immediate security fallout projected. Also, the still under-researched indirect and long-term impacts of climate on conflict—such as a heat wave destroying a farming community’s livelihood, driving the community’s young men to migrate, potentially inflaming territorial and sectarian violence— can also be projected and anticipated by security and defense forces.

A very readable 2007 journal article by Barnett and Adger discusses the underlying causes of conflict and how climate change could drive conflict. They propose a basic 3-prong research regime of identifying livelihoods vulnerable to climate hazards, examining the consequences of damage to these livelihoods, and understanding the role of institutions in managing climate hazards so that they do not become security problems (e.g., by protecting livelihoods).

Who else should pay attention to climate’s link to conflict?

Those working on economic, social and international development policy, human rights organizations, and those working in the capacity of a negotiator should anticipate the impact of extreme heat and other climate stressors on their constituents, both individuals and communities. People working in the field of restorative justice and other disciplines focused on reducing violence and criminalization of historically disadvantaged communities should also track the effect of climate stressors on their project outcomes, and adapt programs accordingly. Those working for non-violent solutions within urban conflict zones might ramp up their mediation efforts in particularly hot summers.

You also can watch your own behavior in response to climate-induced stress. On the next hot day you might take a second to breathe before honking at a car stopped at a green light… you might just be behind an experimental psychologist with a stopwatch.