News release: “The study, which includes more data than prior research in this field and covers all major regions of the globe, shows the Earth’s climate plays a more influential role in human affairs than previously thought. The results were published (Thursday, Aug. 1) in the journal Science. The authors found similar patterns of conflict around the world that were linked to changes in climatic, such as increased drought or higher than average annual temperature. Examples include spikes in domestic violence in India and Australia; increased assaults and murders in the United States and Tanzania; ethnic violence in Europe and South Asia; land invasions in Brazil; police using force in the Netherlands; civil conflicts throughout the tropics; and even the collapse of Mayan and Chinese empires…

They examined various aspects of climate such as rainfall, drought or temperature, and their associations with various forms of violence within three broad categories of conflict:

• Personal violence and crime such as murder, assault, rape, and domestic violence;
• Intergroup violence and political instability, like civil wars, riots, ethnic violence, and land invasions;
• Institutional breakdowns, such as abrupt and major changes in governing institutions or the collapse of entire civilizations.

The results proved all three types of conflict exhibit systematic and large responses to changes in climate, with the effect on intergroup conflict being the most pronounced. Conflict responded most consistently to temperature, with all 27 out of 27 studies of modern societies finding a positive relationship between high temperatures and greater violence.”

• Also, via Climate Central –  Climate & Conflict: Warmer World May be More Violent