The observation that the future of Antarctica is very much dependent on temperature provides a key thread to the projection.

"When the various contributions to sea-level rise are related to global mean surface temperature they all become good or bad together, which means the best-case scenario is better and the worst-case is worse as the degree of uncertainty increases," Dewi le Bars from the Royal Netherlands Meteorological Institute told environmentalresearchweb.

To generate their probability density function, the researchers considered factors such as ocean dynamics and steric expansion, glaciers and ice caps, Antarctic and Greenland ice sheets and land water storage. They also examined the uncertainty related to confidence in climate model projections of global mean temperature, and incorporated the latest Antarctic mass loss estimates provided by the scientific community.

Understanding Antarctica in detail is a major part of the puzzle, but because the region is hard to reach and has challenging weather, scientists have relatively little data.

"It is very difficult to guess what is under the thick ice sheet, and decipher where the ice stops and the land starts," said le Bars. "This is very important for us because if the ocean is able to reach the bottom of the ice then the sheet melts a lot faster."

Progress is being made, but ice dynamics are complex and the fact that sheets can break suddenly and quickly makes the behaviour hard to model.

The team has built its projection to look at high-end numbers such as a sea-level rise of 3 m. To put this in context, a sea-level rise of less than half this value could translate to annual flooding affecting somewhere between 0.2 and 4.6% of the world’s population, and global costs for protecting the coast of $71 billion.

The team reported the work in Environmental Research Letters (ERL).

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