Rising sea levels threaten survival of cities like Kolkata: Pachauri

Rising sea levels due to climate change are threatening the survival of big cities located near coastal areas like Kolkata, Shanghai and Dhaka, said Dr RK Pachauri, chairperson of the Intergovernmental Panel on Climate Change (IPCC).

“There is a very high risk in delta cities like Kolkata, Shanghai and Dhaka. They are very vulnerable to the impacts of climate change due to sea level rise and coastal flooding. Both people and property would be affected in such a scenario,” Pachauri told reporters.

Asking governments worldwide to start adaptation measures as soon as possible to counter the effects of climate change, the scientist said the matter has to be taken up in all seriousness.

“Scientific factors are evident. We cannot keep our eyes shut,” he said.

Earlier, delivering the convocation address at the Indian Institute of Management, Calcutta, last night, Pachauri said, “Partial loss of ice sheets on polar land could imply metres of sea level rise, major changes in coastline, and inundation of low lying area, with greatest effects in river deltas and low-lying areas.”

Such changes are projected to occur over millennial timescales, but more rapid sea level rise on century timescales cannot be excluded, he warned.

IPCC’s fourth assessment report on climate change had stated, “Warming of the climate system is unequivocal, as is now evident from observations of increases in global average air and ocean temperatures, widespread melting of snow and ice, and rising global sea average level.” More

 

Fear of 'catastrophic' sea-level rise as ice sheets melt faster than predicted

Glaciologists fear they may have seriously underestimated the potential for melting ice sheets to contribute to catastrophic sea-level rises in coming decades which could see increases of a metre or more by 2100.

The ice sheets of Greenland and Antarctica contain about 99.5 per cent of the Earth's glacier ice and could raise sea levels by 65 metres if they melted completely – although experts think this is highly unlikely in the foreseeable future. However, a survey of the world's top 26 glaciologists found most believe melting of the ice sheets could be more rapid and severe than previously estimated. They believe that melting of the ice sheets alone this century would be likely to raise the average global sea level by 29cm, the poll found, but there is a five per cent chance of it increasing even further by a catastrophic 84cm.

This would take the total sea-level increase to well over a metre if other factors such as the thermal expansion of oceans and runoff from mountain glaciers are taken into account.

"Our analysis shows the biggest uncertainty when it comes to sea levels is the contribution from the ice sheets," said Professor Jonathan Bamber of Bristol University, lead author of the study published in the journal Nature Climate Change.

"It shows glaciologists believe there is a one-in-20 chance of sea levels rising by a metre or more by 2100, and a metre rise in sea level is really very serious.

"The impacts of sea-level rise of this magnitude are potentially severe, implying a conceivable risk of the forced displacement of up to 187 million people within this century."

Rising sea levels are one of the greatest uncertainties of climate change. A warmer world causes oceans to expand thermally but also leads to faster melting of mountain glaciers and some regions of the polar ice sheets. More