Annual S.T. Lee Lecture in Antarctic Studies

The Greenland Ice Sheet is reacting to climate change, and is losing progressively more mass every year. One of our challenges in the future is to adapt to rising sea level. Looking into the past provides knowledge on how the ice sheets react to changing climate, and this can be used to improve future predictions of sea level rise.

The deep ice cores from Greenland contain information on past climate that goes back more than 130,000 years, telling tales about past abrupt climate and sea level changes. The last interglacial, 130,000 to 115,000 years before present, is a key analogue for future climate. At this time, the climate was 5°C warmer over Greenland, and global sea level was 6-9 m higher than present. All the ice cores from Greenland show that the ice sheet survived, making only a modest contribution to global sea level rise of approximately 2m at this time.

These findings imply that Antarctica was a major contributor to sea level rise during this past warm period, and may respond similarly in the future.

Dorthe Dahl-Jensen is a Professor at the Niels Bohr Institute, University of Copenhagen. Professor Dahl-Jensen has participated in more than 25 field seasons on ice core drilling projects including leading several international deep drilling projects like the North Greenland Ice Core Project (NGRIP), North Greenland Eemian Ice Drilling Project (NEEM) and the East Greenland Ice Core Project (EGRIP).