Earth's hemispheres may have worked together to drive past ice ages

New research from the University of St Andrews has uncovered a previously unknown process that may have helped drive Earth into past ice ages. Published today (Oct. 22) in the Journal of Climate, the paper links ice sheets in the Northern Hemisphere to changes in ocean circulation and sea ice in the Southern Hemisphere understood to drive down atmospheric CO₂. Linking these two key features of the ice ages has long been a challenge, given how far apart the two regions are.