Linear response functions to project contributions to future sea level

Published: Oct 1, 2012 by The PISM Authors

Linear response functions can separately estimate the sea-level contributions of thermal expansion and solid ice discharge from Greenland and Antarctica. This formalism introduces a time-dependence which allows for future rates of sea-level rise to be influenced by past climate variations. The linear response function for the solid ice discharge is computed with the Potsdam Parallel Ice Sheet Model PISM-PIK (Winkelmann et al. 2011) under surface warming scenarios. Different from earlier studies we conclude that solid ice discharge from Greenland due to dynamic thinning is bounded by 0.42 m sea-level equivalent. Ice discharge induced by surface warming on Antarctica is best captured by a model which reflects the fact that ice loss increases with the cumulative amount of heat available for softening the ice in our model.