There is evidence that the 2007−2010 drought contributed to the conflict in Syria. It was the worst drought on record, causing widespread crop failure and a mass migration of farming families to urban centers. Century-long observed trends in precipitation, temperature, and sea-level pressure, supported by climate model results, strongly suggest that anthropogenic forcing has increased the probability of severe and persistent droughts in this region, and made the occurrence of a 3-year drought as severe as that of 2007−2010 2 to 3 times more likely than by natural variability alone.
A study published in Proceedings of the National Academy of Sciences on 2 March 2015 conclude that human influences on the climate system are implicated in the current Syrian conflict. They say the drought that played a role in triggering the catastrophic Syrian Civil War was the worst such climate event in at least the past 900 years, and was partly caused by man-made global warming according to .
The study bolsters the conclusions from other research that found that because of human-made global warming, the drought was made three times more likely to occur, and that it was one of a number of factors that led to the outbreak of hostilities in 2011.
The new study examined tree-ring records showing the annual precipitation history from recent years back to the year 1100, across an area stretching from southern Europe to northern Africa to the Levant region of the Middle East.