The researchers from University of New Hampshire has shown that the most likely explanation for the initiation of Antarctic glaciation during a major climate shift 34 million years ago.
Matthew Huber of the UNH Institute for the Study of Earth, Oceans, and Space and department of Earth said that the Eocene-Oligocene transition was a major event in the history of the planet and their results really flipped the whole story on its head.
Huber said that the textbook version had been that gateway opening, in which Australia pulled away from Antarctica, isolated the polar continent from warm tropical currents, and changed temperature gradients and circulation patterns in the ocean around Antarctica, which in turn began to generate the ice sheet. They had shown that, instead, CO2-driven cooling initiated the ice sheet and that this altered ocean circulation.
Huber asserted that one of the things they were always missing with their CO2 studies, and it had been missing in everybody's work, is if conditions were such to make an ice sheet form, perhaps the ice sheet itself was affecting ocean currents and the climate system that once one start getting an ice sheet to form, maybe it became a really active part of the climate system and not just a passive player.
The study is published in Nature.