When Busted sang about having been to the year 3000 — where ‘not much has changed, but they lived underwater’ — who’d have suspected it might be prophetic?
If the Antarctic Ice Sheet continues to melt, the sea level could rise as high as 17 feet in the next millennium.
This is the warning of a team of researchers led from Hokkaido University, who modelled the fate of the Antarctic ice sheet beyond the 21st century.
The team stated that although the “business as usual” forecast looks bad, it could be avoided if greenhouse gases are reduced, which would keep sea level rise below one foot.
Without costly and extensive coastal protection, substantial sea level rise may make large areas of coastal land that are densely populated uninhabitable.
The sea level could rise up to 17ft by the end of the millennium if Antarctica’s ice sheets continue to melt due global warming. Photograph: Antarctica
“This paper by Christopher Chambers, a Japanese meteorologist and author of the study on Antarctic climate change,” said Christopher Chambers from Japan’s Hokkaido University.
‘The most severe consequences — multi-meter contribution to sea-level rise — will likely only be seen later,’ he added.
“Future work will involve basing simulations upon more realistic futureclimate scenarios and using other ice sheet models to model them.
In their study, Dr Chambers and colleagues build upon existing research — the so-called ‘Ice Sheet Model Intercomparison Project for the Coupled Model Intercomparison Project Phase 6’, or ‘ISMIP6’ for short.
The international project, which was aptly named “The International Project”, used the most recent climate models to predict the effects of global warming on Antarctica’s and Greenland’s ice sheets at the end of this century.
The results — which informed the recent Sixth Assessment Report of the Intergovernmental Panel on Climate Change — found that, under unabated warming, the Antarctic will contribute some 3–12 inches (8–30 cm) to sea level rise.
This figure, however, could be curbed to just 0–1 inches (0–3 cm) in scenario where greenhouse gas emissions were significantly reduced.
The researchers extended ISMIP6’s projections further into the future — considering both unabated warming and reduced emissions trajectories — using an ice sheet model known as ‘Simulation Code for Polythermal Ice Sheets (SICOPOLIS).
Up until the year 2100, the simulation ran exactly the same as in the original ISMIP6 experiments — beyond which, the team assumed that the late 21st-century climatic conditions remained constant, so no further climate trend was applied.
From the models’ outputs, the team focussed on the total mass change of the southern continent’s ice sheets and regional changes in East and West Antarctica and on the Antarctic Peninsula — as well as the contributors to such.
The researchers extended ISMIP6’s projections further into the future — considering both unabated warming and reduced emissions trajectories — using an ice sheet model known as ‘Simulation Code for Polythermal Ice Sheets (SICOPOLIS). The sea-level contribution of the Antarctic ice sheets to the simulated mass loss is shown in this picture.
By the year 3000, sea levels could rise by as much as 4.9–17.7 feet (1.5–5.4 metres) under current warming trends — resulting in the largest part from the collapse of the West Antarctic ice sheet.
Could emissions be curbed, however, the researchers’ models suggest that sea level rise could be constrained to just 0.4–1 feet (0.13–0.32 metres).
The potential collapse of the West Antarctic ice sheet would be made possible, the team noted, by the fact that it is grounded on a bed that is mostly below sea level.
Journal of Glaciology has published all findings.