Farmers ride in their tractor in the drought-hit region of Hasaka in northeastern Syria on June 17, 2010.

Farmers ride in their tractor in the drought-hit region of Hasaka in northeastern Syria on June 17, 2010.

We know the basic story in Syria by now: From 2006-2010, an unprecedented drought forced the country from a groundwater-intensive breadbasket of the region to a net food importer. Farmers abandoned their homes—school enrollment in some areas plummeted 80 percent—and flooded Syria’s cities, which were already struggling to sustain an influx of more than 1 million refugees from the conflict in neighboring Iraq. The Syrian government largely ignored these warning signs, helping sow discontent that ultimately spawned violent protests ... A preventable drought-triggered humanitarian crisis sparked the 2011 civil war, and eventually, ISIS. A new study published Monday in the Proceedings of the National Academies of Science provides the clearest evidence yet that human-induced global warming made that drought more likely. The study is the first to examine the drought-to-war narrative in quantitative detail in any country, ultimately linking it to climate change.

Analysts often point to many factors that contributed to the rise of ISIS. Sunni frustration with the Shi'a-dominated central Iraqi government, the remnants of Al Qaeda in Arabia, and of course the disastrous U.S.-led war just to name a few. But another factor may have played an early role in destabilizing Syria It's unfortunate that we in the U.S. have senior policymakers playing rhetorical games with snowballs as the world warms up and populations are displaced. But climate change denial isn't just bad science, it's bad business. And since our elected leaders increasingly take marching orders from corporate America instead of we the people, perhaps we can hope global energy companies and related firms, many of which are highly leveraged in the Middle East, will conclude that simply denying climate change is bad for their shareholders.