FOSSIL PLANTS found beneath MILE-DEEP GREENLAND ICE—indicating risk of rapid sea-level rise

Long-lost Camp Century ice core provides direct evidence that giant ice sheet melted off within the last million years and is highly vulnerable to a warming climate, PNAS study shows. 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. Over the last year, Christ and an international team of scientists—led by Paul Bierman at UVM, Joerg Schaefer at Columbia University and Dorthe Dahl-Jensen at the University of Copenhagen—have studied these one-of-a-kind fossil plants and sediment from the bottom of Greenland. Their results show that most, or all, of Greenland must have been ice-free within the last million years, perhaps even the last fe