Mar 30, 2016

Contribution of Antarctica to past and future sea-level rise

by
Robert M. DeConto, David Pollard
,
Nature
  • States polar temperatures over the last several million years have, at times, been slightly warmer than today, yet global mean sea level has been 6–9 metres higher as recently as the Last Interglacial (130,000 to 115,000 years ago) and possibly higher during the Pliocene epoch (about three million years ago)
  • States in both cases the Antarctic ice sheet has been implicated as the primary contributor, hinting at its future vulnerability
  • Uses a model coupling ice sheet and climate dynamics—including previously underappreciated processes linking atmospheric warming with hydrofracturing of buttressing ice shelves and structural collapse of marine-terminating ice cliffs—that is calibrated against Pliocene and Last Interglacial sea-level estimates and applies this to future greenhouse gas emission scenario
  • Finds Antarctica has the potential to contribute more than a metre of sea-level rise by 2100 and more than 15 metres by 2500, if emissions continue unabated
  • Finds that in this case atmospheric warming will soon become the dominant driver of ice loss, but prolonged ocean warming will delay its recovery for thousands of years