Zhonghui Liu of the University of Hong Kong has made the most comprehensive deep-sea core research to date Global Cooling During the Eocene-Oligocene Climate Transition. Global SST's fell by an average of 4.5 to 6 degrees F at the E-O boundary, with temps near the South Pole and North Pole dropping 9 to 11 degrees. An atmospheric CO2 drop is the most likely culprit for such widespread cooling, Lui says. But what caused the theoretical greenhouse-gas plunge remains to be shown. Amazingly, Antartica would have been free of ice and populated by primitive dinosaurs before the E-O boundary event incidentally.