It’s a hot day; sweat soaks your forehead, and you just want to get back to your air-conditioned home, so of course you’re going to be angry if the car in front of you doesn’t move when the traffic light turns green. Honk! Honk!

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.

“It does change how we think about the value of avoiding climate change,” said Solomon Hsiang, lead study author and researcher at the University of California, Berkeley. “It makes us think that avoiding climate change is actually something we should be willing to invest more in.”

Future populations will hopefully also be able to figure out ways to adapt to these climate events, such that the predicted increase in violence will become less likely. Large-scale changes in technologies or political institutions may also alter the risk of violence in the future, Hsiang said.

Research on this topic is making waves. A 2011 report, in which Shepherd participated, found that new national security challenges will arise for the U.S. Navy, Marine Corps and Coast Guard if even moderate trends in climate change continue.

“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.

Indirectly, analyses such as Hsiang’s can influence discussions about climate policy in general.

“If the world that these studies project will arrive in mid-century looks pretty unpleasant, then one obvious response is to be more serious about reducing greenhouse gas emissions,” Homer-Dixon said.

It remains to be seen whether this research will indeed get policy makers hot and bothered enough to enact change.

 – CNN