Scientists have known since the GISP2 borehole was drilled in 1993 that Central Greenland deglaciated at least once in the late Pleistocene (Bierman et al., 2024). Indeed, the Summit of the modern Greenland ice sheet was actually ice-free at some point between 250,000 and 1.1 million years ago – which is relatively recent from a geological perspective.
Plants, wood, insects, fungi and other remnants suggestive of vegetation were recovered from the bottom of the boring site. This is quite a contrast to today’s 3000-meters-high ice sheet at this same location.
“The presence of poppy, spike-moss, fungal sclerotia, woody tissue, and insect parts in the GISP2 till shows that tundra vegetation once covered central Greenland, mandating that the island was largely ice-free.”