A new study says the predictions of a major rise in sea levels due to the melting to the Antarctic ice are unrealistic, and a more moderate increase is likely.

An article on bbc.com cites the latest work, done by researchers from the Université Grenoble Alpes, France, and from the Open University, UK.

Their research focused on study models that predict how the polar ice will react to an increase in greenhouse gas emissions that range from a medium to high rate.  The study says the most likely outcome is a rise of less than four inches by the year 2100, if current trends continue.

Earlier predictions of as much as 12 inches of increase in worldwide sea levels has just a one-in-20 chance of happening, according to the research team.

Dr. Tasmin Edwards, from the Open University, said they had run some 3,000 models, and compared their simulations to what is going on in the Amundsen Sea, off the west coast of Antarctica.  Satellite observations of the ice in the area have recorded some pronounced retreating of the ice that borders the sea and these glaciers are generally considered unstable.

Their study looked also at the bedrock of Antarctica, calling that an important part of what is going on, and found it was too bumpy and not sloping in a way that would allow any collapse of ice into the ocean very rapidly.

The team adds it could happen over a longer period of time, in a few hundred or a thousand years, but they did not think the ice can react in a hundred-year period that dramatically.

Some earlier studies had predicted a high-impact collapse from the unstable ice to add 20-30 inches to the sea levels, but the new study says those predictions “just aren’t plausible.”

The researchers cautioned their study only looked at the impact from the Antarctic, and did not consider the melting of glaciers in Greenland or the expansion of the ocean water due to warming temperatures.

The findings of the new study were published in the journal Nature and was led by Dr. Edwards and Catherine Ritz.