We know a lot about how carbon dioxide (CO2) levels can drive climate change, but how about the way that climate change can cause fluctuations in CO2 levels? New research from an international team of scientists reveals one of the mechanisms by which a colder climate was accompanied by depleted atmospheric CO2 during past ice ages.The overall goal of the work is to better understand how and why the earth goes through periodic climate change, which could shed light on how man-made factors could affect the global climate.