India hopes to participate in the international assessment of the phenomenon of rise in sea-level, said Shailesh Nayak, Secretary to the Union Ministry of Earth Sciences.

Though Indian scientists have participated in the assessment, India had not yet officially been part of the assessment.

He told The Hindu over phone from New Delhi that the assessments by the International Panel of Climate Change (IPCC) had put the Indian Ocean sea level rise (which is considered faster than other oceans) at 3 mm to 6 mm per year. But Indian assessments have put it at 1.3 mm per year.

While international assessment was based on altimeter readings in the middle of the sea, Indian assessment was based on data from tidal stations on the shore.

International assessment was for the entire ocean whereas Indian assessments were specific to the shore.

“We need to build our projections matching international projects and our model is now ready,” he said, and hoped that the next international assessments would take this into consideration.

It was important to participate in the international assessment as “our viewpoint too will get heard”, Mr. Nayak said.

Mr. Nayak, who attended a conference in Mangaluru recently, had then said that rising sea-level was “not necessarily because of global warming and that there could be multiple causes”.

On the significance of the rise, Mr. Nayak said, “When you want to see the change, you have to minus [subtract] the variability [factor] to find out the actual change. When that is done, it is more or less the same [as other oceans].”

Projections

With the rise in sea-level, sediment pattern, erosion and deposition patterns would change which needed better understanding. His Ministry was trying to make projections so that one knew what would happen by 2030 or 2050. This would enable the authorities to invest appropriately. “We need not invest in an area that is not going to be affected,” he said.

Secondly, the projections were being made to understand what would happen if sea-level changed by about 50 cm by 2050, for example. Answers would be known in three to five years.

The Secretary to the Union Ministry of Earth Sciences, says rise in sea-level may not just be because of global warming