Greenland cave discovery reveals the Arctic temperature millions of years ago

By Raquel Brandao – earth.com

Cave minerals from far northern Greenland show that the High Arctic once thawed and flowed with liquid water. The new record points to mean annual air temperatures roughly 25 degrees Fahrenheit warmer than today.

Those minerals grew between roughly 9.5 and 5.3 million years ago, a warm slice of the Late Miocene. The samples indicate brief swings to small glaciers between warm spells, revealing a region that shifted quickly when conditions changed.