From the WaPo Wonk Blog:
WP: To be clear here, you’re not saying drought caused the conflict. But these environmental stresses were an overlooked factor in creating unrest?
FF: The conflict is ongoing, so it’s hard right now to study the dynamics in Syria and look at exactly how population movements might have put pressure on the economic and social dynamics in various areas. So we’re not making any claim to causality here. We can’t say climate change caused the civil war. But we can say that there were some very harsh climatic conditions that led to instability.