EGU2020-19502, updated on 12 Jun 2020
EGU General Assembly 2020
© Author(s) 2020. This work is distributed under
the Creative Commons Attribution 4.0 License.

Doubling of future Greenland Ice Sheet surface melt revealed by the new CMIP6 high-emission scenario

Stefan Hofer1, Charlotte Lang2, Charles Amory2, Christoph Kittel2, Alison Delhasse2, Andrew Tedstone3, Patrick Alexander4, Robin Smith5, and Xavier Fettweis2
Stefan Hofer et al.
  • 1University of Oslo, Department of Geosciences, Oslo, Norway. (
  • 2Laboratory of Climatology, Department of Geography, University of Liège, Belgium
  • 3Department of Geosciences, University of Fribourg, Switzerland
  • 4NASA Goddard Institute for Space Studies, Columbia University, USA
  • 5National Centre for Atmospheric Science, Department of Meteorology, University of Reading, UK

Future climate projections show a marked increase in Greenland Ice Sheet (GrIS) runoff
during the 21st century, a direct consequence of the Polar Amplification signal. Regional
climate models (RCMs) are a widely used tool to downscale ensembles of projections from
global climate models (GCMs) to assess the impact of global warming on GrIS melt and
sea level rise contribution. Initial results of the CMIP6 GCM model intercomparison
project have revealed a greater 21st century temperature rise than in CMIP5 models.
However, so far very little is known about the subsequent impacts on the future GrIS
surface melt and therefore sea level rise contribution. Here, we show that the total GrIS
melt during the 21st century almost doubles when using CMIP6 forcing compared to the
previous CMIP5 model ensemble, despite an equal global radiative forcing of +8.5 W/m2
in 2100 in both RCP8.5 and SSP58.5 scenarios. The total GrIS sea level rise contribution
from surface melt in our high-resolution (15 km) projections is 17.8 cm in SSP58.5, 7.9 cm
more than in our RCP8.5 simulations, despite the same radiative forcing. We identify a
+1.7°C greater Arctic amplification in the CMIP6 ensemble as the main driver behind the
presented doubling of future GrIS sea level rise contribution

How to cite: Hofer, S., Lang, C., Amory, C., Kittel, C., Delhasse, A., Tedstone, A., Alexander, P., Smith, R., and Fettweis, X.: Doubling of future Greenland Ice Sheet surface melt revealed by the new CMIP6 high-emission scenario, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-19502,, 2020