A new study presents more evidence of the link between aggression and warmer temperatures. According to the study by economist Matthew Ranson, historic crime data and temperature data show that warmer weather leads to more murders, rapes, aggravated assaults, robberies, larceny, and theft.
Using crime and weather data dating back 30 years for 2,997 US counties, Ranson’s study finds that temperature has “a strong positive effect” on criminal behavior. According to the study, between 2010 and 2099, rising temperatures due to climate change will cause an additional 22,000 murders, 180, 000 rapes, 1.2 million aggravated assaults, 2.3 million simple assaults, 260,000 robberies, 2.2 million cases of larceny, and 580,000 cases of vehicle theft in the United States.
Though controversial, Ranson’s study is not the first to link climate change to increased aggression and violence. In August, researchers at UV Berkeley released a study in the peer-review journal Science, drawing a link between increased rates of violent crime and a warming climate.
Their study utilized data from 27 modern societies, which all showed a correlation between increased rates of violence and higher temperatures. The study projects that war and civil unrest may increase by as much as 56 percent between 2013 and 2050, while episodes of murder, rape, assault, and domestic abuse could increase by 16 percent during the same time period.
“To the extent that climate change causes people to be out and interacting more, there will be more crime,” John Roman, a senior fellow at the Urban Institute’s Justice Policy Center, told Mother Jones. For instance, police have long known that crime often increases as temperatures go up because people tend to be out-of-doors interacting more.
Intelligence agencies have also long been aware that climate change could produce additional conflict. Changing weather patterns such as increased flooding, drought, and extreme storms may lead to loss of habitable land, human displacement, and climate refugees. Under those circumstances, there is an increased opportunity for religious conflict and political violence.
The Pentagon and intelligence agencies have been looking at the national security implications of climate change for years. Last summer, the Pentagon announced that climate change has prompted its strategists to rethink security and consider “global food and water scarcity, mass migration, and the potential for those issues to ignite clashes around the world.”
Both national and international lawmakers will have to address how to adapt law enforcement and security practices in a changing environment. “The concept fits with classic crime theory so neatly that we need to start thinking about how to get ahead of this and respond,” Roman, of the Urban Institute’s Justice Policy Center, added.