Greenland Ice Sheet and rising sea level in a worst-case climate change scenario

Models that simulate sheet flow in the Greenland Ice Sheet balance forces at gridpoints in the map plan, which allows only a slow response to changes in climate forcing. A holistic approach to modeling allows a rapid response that takes place in ice streams. Holistic modeling results are presented that lengthen and lower the profiles of Greenland ice streams. This occurs because surface meltwater from greenhouse" warming reaches the bed through crevasses, and thereby increases basal water pressure. Thinning is then controlled primarily by increased basal water pressure that lengthens ice streams. If thinning caused by this process is both rapid and simultaneous for the major Greenland ice streams, the resulting iceberg outbursts might trigger an episode of rapid climate change.