How is Antarctica melting? Much faster than we hoped, according to the latest research — neatly explained in the latest Peter Sinclair This Is Not Cool video for Yale Climate Connections (formerly the Yale Forum), cunningly titled Meltwater Pulse 2b. Just how fast the West Antarctic Ice Sheet will melt, and how much East Antarctica will contribute to near term sea level rise is open an open question, but the news is not good, as the latest research on the stability of the Antarctic ice sheet at the end of the last ice age suggests.
Two new papers published this week suggest that the West Antarctic glaciers draining into the Amundsen Sea — the Pine Island, Thwaites, Haynes, Pope, Smith and Kohler glaciers — are melting rapidly and are now committed to collapse, adding up to 1.2 metres to future sea level rise. In the NASA JPL video above, Eric Rignot, lead author of a paper1 examining how the glaciers’ “grounding lines” — the point where the bottom of the glacial ice leaves the bedrock and starts to float — have retreated very significantly over the last 20 years explains how they are now melting back unstoppably. Another paper modelling ice loss from the Thwaites glacier 2 finds that it is committed to retreat and collapse via the same mechanism. Lead author Ian Joughin of the University of Washington, told Science magazine:
The next stable state for the West Antarctic Ice Sheet might be no ice sheet at all…
- E. Rignot, J. Mouginot, M. Morlighem, H. Seroussi, B. Scheuchl. Widespread, rapid grounding line retreat of Pine Island, Thwaites, Smith and Kohler glaciers, West Antarctica from 1992 to 2011. Geophysical Research Letters, 2014; DOI: 10.1002/2014GL060140 [↩]
- Ian Joughin, Benjamin E. Smith, Brooke Medley. Marine Ice Sheet Collapse Potentially Underway for the Thwaites Glacier Basin, West Antarctica, Science, DOI: 10.1126/science.1249055. [↩]