Greenland Ice Sheet is More Sensitive to Climate Change than Previously Understood Written by AZoCleantechMar 16 2021 In 1966, US Army scientists drilled down through nearly a mile of ice in northwestern Greenland--and pulled up a fifteen-foot-long tube of dirt from the bottom. Then this frozen sediment was lost in a freezer for decades. It was accidentally rediscovered in 2017. In 2019, University of Vermont scientist Andrew Christ looked at it through his microscope--and couldn't believe what he was seeing: twigs and leaves instead of just sand and rock. That suggested that the ice was gone in the recent geologic past--and that a vegetated landscape, perhaps a boreal forest, stood where a mile-deep ice sheet as big as Alaska stands today.