New Delhi, June 3 -- The Antarctic Ice Sheet, which has the biggest potential for sea-level rise, may be at or very close to a melting tipping point, according to a new study. In the phase beyond this point, the ice sheet cannot stop melting even if global warming is contained or reversed.

In the scientific parlance, such behaviour is called 'hysteresis'. This means the process (in this case melting) has entered an input-output loop and can keep occuring independently.

Researchers at the Norwegian research organisation NORCE Research, United Kingdom's Northumbria University and Germany's Potsdam University (PIK) have confirmed hysteresis behaviour in the the Antarctic Ice Sheet.

Ice sheets take hundreds - sometimes thousands - of year...