What caused the end of the Ice Age? It’s a 20,000-year old mystery that’s being tackled by climate scientists across the county. Answering this question is not just about understanding the past -- it’s about developing a unified theory of the atmospheric system. And it can help refine climate models that project current and future rates of warming.   Aaron Putnam and his research team from the University of Maine are searching for clues as to what caused this rapid melting of glaciers and ice sheets. To find answers, Putnam's team traveled to a remote ice field in the Mongolian Altai, a vast range of mountains that touch Russia, Mongolia, China and Kazakstan. This story is brought to us by Kevin Stark. He’s an environmental journalist who lives in Chicago. He embedded with Putnam’s team for the entire 6-week journey, a part his work as a Comer journalism fellow at Northwestern University. Make sure to read Kevin’s companion piece at Pacific Standard Magazine: http://bit.ly/2eJbZ4T Thanks to our sponsor, Wunder Capital. Create an account for free and invest directly in U.S. solar projects: Wundercapital.com/warm