Rebuttal: 'Greenland ice sheet is a 3 km thick chunk of ice spread across a 1000 km wide island. You could visualize it as being a thick piece of paper. Can you imagine a piece of paper lying flat on a table, collapsing? The land under ice sheet is depressed due to weight ofice above it, & is bowl shaped. Furthermore, the island is full of mountain ranges buried under ice – which prevent lateral movement'