On the response of the Greenland ice sheet to greenhouse climate change

• Main Author: Greve, Ralf
• Format: Article in Journal/Newspaper
• Language: English
• Published: Kluwer Academic Publishers
• Subjects: Greenland; Ice sheet; Greenhouse gas; Climate change; Modelling; 451; Ice Sheet
• Online Access: http://hdl.handle.net/2115/34701; https://doi.org/10.1023/A:1005647226590

Numerical computations are performed with the three-dimensional polythermal ice-sheet model SICOPOLIS in order to investigate the possible impact of a greenhouse-gas-induced climate change on the Greenland ice sheet. The assumed increase of the mean annual air temperature above the ice covers a range from ΔT = 1℃ to 12℃, and several parameterizations for the snowfall and the surface melting are considered. The simulated shrinking of the ice sheet is a smooth function of the temperature rise, indications for the existence of critical thresholds of the climate input are not found. Within 1000 model years, the icevolume decrease is limited to 10% of the present volume for ΔT ≤ 3℃, whereas the most extreme scenario, ΔT = 12℃, leads to an almost entire disintegration, which corresponds to a sea-level equivalent of 7 m. The different snowfall and melting parameterizations yield an uncertainty range of up to 20% of the present ice volume after 1000 model years.