The existing understanding of interglacial periods is that they are initiated by Milankovitch cycles enhanced by rising atmospheric carbon dioxide concentrations. During interglacials, global temperature is also believed to be primarily controlled by carbon dioxide concentrations, modulated by internal processes such as the Pacific Decadal Oscillation and the North Atlantic Oscillation. Recent Work challenges the fundamental bases of these conceptions.
Journal of Climatology, Volume 2014, Article ID 345482
http://dx.doi.org/10.1155/2014/345482
Interglacials, Milankovitch Cycles, and Carbon Dioxide