Friday, August 02, 2013

Climate change may increase violence, study shows

By Elizabeth Landau, CNN
updated 6:41 AM EDT, Fri August 2, 2013


When the temperature rises, so does aggression -- and that can lead to large-scale consequences, considering that climate change is turning up the heat over the entire planet.

A new study in the journal Science shows that shifts in climate historically have been associated with violent conflicts, among both individuals and groups, and that current warming patterns could significantly increase the abundance of human conflict by midcentury.

Researchers' meta-analysis of 60 studies suggest that, consistent with links between conflict and climate shifts in the past, the risk of intergroup conflict around much of the planet would be amplified by 50% in 2050.


Studies both in laboratory settings and of "natural" human situations have found a connection between heat and violence (PDF), the study said. Higher temperatures have been linked to both innocuous hostile behaviors, such as horn-honking while driving, and more serious behaviors such as domestic violence within households, assault and rape. Police officers are also more likely to use force at higher temperatures, studies have found.

Conflict is also associated with extreme rainfall, particularly in societies dependent on agriculture. Higher rates of personal violence are found in low-income settings, where agriculture income suffers from extremely wet or dry conditions.

The Mayan civilization appears to have collapsed during long periods of drought, Hsiang said. The same global climate event seems to have brought down the Tang dynasty in China -- in fact, according to Hsiang, most Chinese dynasties collapsed during dry spells.


Shifts in temperature and rainfall influence economic productivity and food prices, which may influence discontent and therefore riots. Climate changes can force the displacement of population, or urbanization, which may lead to clashes over resources.

There's also the mental and physical responses to rising temperatures, which need further scientific investigation. "For instance, climatic events may alter individuals' ability to reason and correctly interpret events, possibly leading to conflicts triggered by misunderstandings," the authors wrote.


"Military, security, and intelligence analysts are now engaged with the issue, and there's a great deal of thought now being given to the long-term security implications of climate change," Homer-Dixon wrote in an e-mail. "There's very little skepticism within these circles about the reality of climate change, nor about the potential risk climate change poses to national and international security."

The scientific community agrees that human activity -- namely burning coal, oil and natural gas -- has been driving a rapid rise of carbon dioxide levels in the atmosphere. This is analogous to turning the dial up on an electric blanket, says Jim Butler, a senior scientist at NOAA; it takes a little while to warm up, and even if we stop emitting carbon dioxide, temperatures would still rise for a decade or two.


No comments:

Post a Comment