Sydney Morning Herald: Sea levels could rise by up to seven metres if greenhouse gas emissions were not scaled back, a panel of leading geoscientists has told the US Congress. The warning came as a vast ice shelf, about 260 square kilometres in size, continued to fall away from Greenland’s Petermann glacier, the largest iceberg shed by the island in half a century. The geoscientists told Congress Greenland might cease to exist, with the island rapidly approaching a tipping point that would see much …