Antarctica Was Last Ice-Free 34 Million Years Ago: What Triggered This Climate Shift?

Antarctica, which is nearly four times the size of the United States, was not always covered in ice. The last time it was ice-free was 34 million years ago during the Eocene-Oligocene boundary. At that time, global temperatures were higher, and carbon dioxide levels in the atmosphere were much higher than today. However, a significant drop in CO2 levels, coupled with …