West Bengal's capital and one of India's densely populated metropolitan city, Kolkata, is all set to face the threat of submergence in the Bay of Bengal, according to an expert.

New Delhi based environmental scientist V Subramanian warned on Tuesday that a large part of Kolkata may be lost at the end of this century if the sea continues to rise.

Subramanian, who teaches at the Jawaharlal Nehru University in New Delhi and is in Patna to deliver a lecture, said that according to the latest data available, the sea is rising at the level of 1cm per year. At this rate the Bay of Bengal would engulf some part of West Bengal, including Kolkata, in the next 100 years.

According to him thermal power plants emit gases like carbon dioxide, sulphur dioxide and methane, which deplete the ozone layer. This causes the ultraviolet rays to penetrate the atmosphere and melt glaciers, which raises the sea level. Thirty per cent of glaciers have already melted, he said and if this continues there would be no glaciers left in the next five decades.

He shocked students, teachers and researchers by revealing that Bangladesh has touched the sea level and is set to submerge. Similarly, he said the Maldives islands would not last more than 100 years and Thailand's capital Bangkok has already started sinking.

He also blamed volcanic eruptions and frequent forest fires for global warming and climatic changes. He said though  the changes were not new, it is occurring at a much faster pace.