Even if the planet doesn't warm as much as it does now, melting ice in Greenland could add at least 1.5 meters and possibly as much as 5 meters to global average sea level. A sediment core from beneath the Greenland ice sheet has provided the first direct evidence that much of the ice has disappeared  during the interglacial period 400,000 years ago, when global temperatures were similar to what they are today. The findings show that even if the planet does not warm as it does now, the loss of ice from Greenland alone would add at least 1.5 meters to global average sea level, and possibly as much as 5 meters This is consistent with existing predictions, but the study provides direct evidence to support them. (Michael Le Page)