Reducing the uncertainty in the past, present, and future contribution of ice sheets to sea-level rise requires a coordinated effort between the climate and glaciology communities. The Ice Sheet Model Intercomparison Project for CMIP6 (ISMIP6) is the primary activity within the Coupled Model Intercomparison Project Phase 6 (CMIP6) focusing on modeling the evolution of the Greenland and Antarctic ice sheets. The ISMIP6 experimental design relies on CMIP climate models and includes, for the first time within CMIP, coupled ice-sheet-climate models as well as standalone ice sheet models. ISMIP6 provides a basis for investigating the feedbacks, impacts, and sea-level changes associated with dynamic ice sheets and for quantifying the uncertainty in ice sheet contribution to sea-level change. The goal of this special issue is to build an evolving volume of refereed and high-quality contributions focusing on both standalone ice sheet models and coupled ice sheet-climate models, as well as new developments to improve the representation of external forcings used by ice sheet models. Such a volume will serve as a unique open reference to the rapidly evolving field of numerical modeling of ice sheet flow of the Greenland and Antarctic ice sheets.

This special issue includes articles reporting results performed in the framework of ISMIP6, including improvements in ice sheet modeling, ice-climate interactions, or external forcings, as well as studies expounding on the ISMIP6 experimental protocol.