Study: Warmer Climate Strongly Affects Human Conflict And Violence

SACRAMENTO (CBS13) - Human violence around the world is being linked to shifts in the climate.

A recent study by researchers at the University of California, Berkeley and Princeton University found the risk of conflict is substantially increased with relatively "minor departures from normal temperatures or rainfall."

Researchers 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 including personal violence, intergroup violence, and institutional breakdowns.

Personal violence includes crimes such as murder, assault, domestic violence, and rape.  Intergroup violence is associated with political instability like civil wars, riots, ethnic violence, and land invasions. Institutional breakdowns refer to abrupt and major changes in governing institutions or the collapse of entire civilizations.

They found all three types of conflict exhibit systematic and large responses to changes in climate.  The intergroup conflict was the most pronounced out of the three.

"We found that 1 standard deviation shift towards hotter conditions causes the likelihood of personal violence to rise 4 percent and intergroup conflict to rise 14 percent," said Marshall Burke, the study's co-lead author in a statement.

Researchers said that exactly why climate affects conflict and violence is the most pressing question for future related research.

"Our results shed new light on how the  future climate will shape human societies," said Burke.  "The findings of the study suggest that a global temperature rise of 2 degrees Celsius could increase the rate of intergroup conflicts, such as civil wars, by over 50 percent in many parts of the world."