The rise in the water level will pose a serious challenge to the coastal areas and endanger the deltas like Sunderbans, said former Geological Survey of India chairman Asis Ghose at a seminar on 'Melting Ice, a Hot Topic' here.

Water vapour causes 36 to 70 per cent of global warming, emission of Carbon Dioxide 9 to 26 per cent and methane 4 to 9 per cent, according to Calcutta University Chemistry Department Professor Shyamal Chakraborty.
Anthropogenic activities, he said, was said to be the basic reason of pollution that caused global warming, and this would give rise to massive outbreak of malaria and dengue by 2020.

The speakers expressed the view that human activities were mainly the attributing factor for global warming.