Rise in sea level doubled in three decades, say researchers

The rise of sea level in the world is around three millimetres per year, which is double the rate three decades ago, a senior scientist said here today.
"The rise in sea level was 1.8 millimetre three decades ago, but it has now increased to three millimetres per year, due to various factors," National Institute of Oceanography (NIO) researcher A S Unnikrishnan said at an event organised to celebrate World Environment Day here.
He said that studies are still on to ascertain the reason behind the rise in sea level, whether it is natural variability or it is due to global warming.

"In the 1970s, thermal expansion and glacier melting accounted for 75 per cent of ocean rise," he said, adding that other factors contributed to the remaining 25 per cent.
Unnikrishnan said that since 1992, satellite altimeters have been used to measure changes in sea level.
"Since the last couple of years, Indo-French satellite SARAL-Altika has been measuring changes in glaciers which contributes to rise in sea level," the researcher who is part of a team monitoring shore water rise, said.

Unnikrishnan said that rising sea level would continue, but people should not fear catastrophes.
"People should not panic if the sea level rises. Even if there is a rise in sea level overnight, it should not be confused with a catastrophe," he said.

Another expert, M Nagarajan from the Goa Institute of Management (GIM) said that sea level changes have to be monitored as the coastal economy is based on it.
"Inundation will impact fishing, tourism and shipping industries. It also amounts to disturbance of marine bio-diversity," he said.
Goa's state environment minister Alina Saldanha also attended the event.