A study into the melting of the Antarctic ice sheet shows how it could cause multi-meter rise in sea levels by the end of the millennium. The conclusion of the Hokkaido University research predicts that continued global warming under current trends will lead to an elevation of the sea level by as much as five meters by the year 3000 CE (Common Era).
The cryosphere is the part of the Earth system comprised of frozen water: ice sheets and glaciers, snow, permafrost and sea ice. As the climate warms, the inevitable response of the cryosphere is enhanced melting. The biggest consequence of this process is with Antarctica.
The focus of the research was upon the long-term perspective for the Antarctic ice sheet beyond the 21st century under global-warming conditions. This formed part of the Ice Sheet Model Intercomparison Project for the Coupled Model Intercomparison Project Phase 6 (ISMIP6). The researchers used the ice-sheet model SICOPOLIS (SImulation COde for POLythermal Ice Sheets) to extend the ISMIP6 through a new series of simulations.
ISMIP6 is part of the World Climate Research Programme (WCRP).the organization is dedicated to addressing frontier scientific questions related to the coupled climate system.
The simulations looked at the total mass change of the ice sheet, regional changes in West Antarctica, East Antarctica and the Antarctic Peninsula, and also the different contributors to mass change.
The simulations of mass loss of the Antarctic ice sheet show that, by the year 3000, the unabated warming pathway produces a sea-level equivalent of as much as 1.5 to 5.4 metres. In contrast, if emissions can be reduced in line with global commitments, the sea level equivalent drops to 0.13 to 0.32 metres.
What is important about the research is that the impact of climate change today on the Antarctic ice sheet extends well beyond the 21st century itself.
The research connects with the growing body of evidence suggesting the acceleration of Antarctic ice-mass loss in recent decades may mark the begin of a self-sustaining and irreversible period of ice sheet retreat and substantial global sea level rise.
Reducing global emissions and tackling global warming could see the eventual stabilization of the ice sheet but when this might happen is unknown. Stabilization is dependent upon how much future climate warming occurs.
In the meantime, the major risk is that as the sea level rises, large areas of densely populated coastal land are at risk from becoming uninhabitable.
The new research appears in the Journal of Glaciology, titled “Mass loss of the Antarctic ice sheet until the year 3000 under a sustained late-21st-century climate.”
