A major Antarctic glacier has passed its “tipping point” and is poised to collapse that could raise global sea levels by 24cm, British scientists have claimed.

According to a University of Oxford team which has developed a three dimensional model to explore changes in the ice sheet, Pine Island Glacier (PIG) has lost increasing amounts of ice over the past decades.

In 2004, satellite observations showed that PIG, one of the many glaciers at the fringes of the West Antarctic ice sheet, had started to thin and that ice was flowing into the Amundsen Sea 25 per cent faster than it had 30 years before.

Now, the new study found that PIG has probably passed a critical “tipping point” and is irreversibly on track to lose 50 per cent of its ice in as little as 100 years, significantly raising global sea levels.

The researchers, however admitted that their model can represent only a simplified version of the physics that govern changes in glaciers, but said if anything, the model is optimistic and PIG will disappear faster than it projects, journal Proceedings of the Royal Society said.

By raising sea levels and therefore the grounding line, in their model, the researchers led by Richard Katz were able to find the point of no return beyond which the glacier would be unable to recover.

According to Katz’s model, the grounding line probably passed over the crest in 1996 and is now poised to enter a period of accelerated shrinking.

The model suggests that within 100 years, PIG’s grounding line could have retreated over 200 kilometres.