Wars are usually caused by struggles for land or power, but one new study is blaming climate change, at least in part, for the start of the Syrian war.

A nationwide drought, the worst Syria has ever seen, ravaged the region from 2006-2010, destroying the agricultural industry and driving farmers to poverty-stricken cities.

Coincidentally, in spring 2011, unrest escalated into a full-blown Syrian war that has since killed at least 200,000 people and displaced millions.

"We're not saying the drought caused the war," Richard Seager, a climate scientist at Columbia University's Lamont-Doherty Earth Observatory who co-authored the study, said in a news release. "We're saying that added to all the other stressors, it helped kick things over the threshold into open conflict. And a drought of that severity was made much more likely by the ongoing human-driven drying of that region."

Previous research has suggested that extreme weather, including high temperatures and droughts, increases the chances of violence. This ranges from mere individual attacks to full-scale wars, as seen in Syria. Some experts believe that man-made global warming, if it hasn't already done so, will escalate future conflicts. As for the case in Syria, researchers are taking a closer look.

The findings are described in the journal Proceedings of the National Academy of Sciences.

Seager and his colleagues found that since 1900, the Fertile Crescent - a region that includes much of Syria, Iraq and Turkey - has heated up by about 2 degrees Fahrenheit (1-1.2 Celsius), and seen a 10 percent reduction in rainfall.

This is bad news for a region that's dependent on agriculture and animal herding. The drought's effects were swift, decreasing agricultural production by a third and wiping out livestock herds. What's more, cereal prices doubled and nutrition-related diseases among children saw dramatic increases.

Thousands of dispossessed farmers fled to the cities, which were already strained by an influx of refugees from the ongoing war in next-door Iraq.

"Rapid demographic change encourages instability," the authors said. "Whether it was a primary or substantial factor is impossible to know, but drought can lead to devastating consequences when coupled with preexisting acute vulnerability."

Data suggests that global warming caused the decrease in precipitation, by weakening wind patterns that might have brought moisture-laden air from the Mediterranean. Additionally, the higher temperatures increased evaporation of soil moisture. This lead to a one-two punch that caused the region's most severe drought in more than a half century.

That, plus issues of poverty, government mismanagement, population growth and other factors triggered rising discontent that has led to a full-blown war in Syria.

And with an already arid and violent Middle East expected to dry even more in coming decades, researchers fear future discontent may come.

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