In the last 50 years, sea level along the Indian coast has risen by 8.5 cm with the decade between 2003 and 2013 showing the annual average rise at a greater speed.
On an average, the sea level along the Indian coast is considered to be rising at about 1.70 mm/year, but during the last decade (2003-2013) (till the time the reading was made) it experienced a rise at a rate of 6.1 mm/year, the Centre informed the Rajya Sabha on Tuesday.
Union Minister Babul Supriyo, however, said since no long-term data on land subsidence or emergence are available, the rate of increase of sea level due to climate change cannot be attributed with certainty. He was responding to a question on whether several cities will submerge in the sea as temperatures are rising due to global warming.
“However, the coastal areas that might get inundated due to the rising sea level need to be evaluated based on their elevation from the sea level. Since no long-term data on land subsidence or emergence are available for these locations, the rate of increase of sea level due to climate change cannot be attributed with certainty,” he said.
“For example, the higher rate of sea level increase at Diamond Harbour is also due to the larger land subsidence happening there. The same may apply to Kandla, Haldia and Port Blair as well,” Supriyo told the Rajya Sabha.
The Minister further said that the rising sea levels can exacerbate the coastal inundation along the low lying areas during extreme events such as tsunami, storm surge, coastal flooding and coastal erosion.
The Government’s observation comes close on the heels of statement from UN Secretary General Antonio Guterres who has described climate change as the biggest threat to sustainability as he voiced deep concern over the rising level of oceans.
“The most vulnerable areas are in Japan, China, Bangladesh and India,” Guterres said speaking to reporters in Bangkok after attending the ASEAN Summit.
A report of the UN’s Inter-Governmental Panel on Climate Change (IPCC) too had warned that global sea levels are set to rise by at least 1m by 2100 if carbon emissions go unchecked, submerging hundreds of cities, including Mumbai and Kolkata, and in some cases entire countries.
“Extreme sea level events that used to happen once a century will occur every year in many parts of the world by the middle of the century because of global warming”, the panel has warned.
The IPCC also warned that glaciers will continue to decline around the world, losing more than a third of their mass by 2100 under worst case emissions scenarios, with some disappearing entirely. Such losses pose “unavoidable consequences for river runoff and local hazards”, and will cause problems for the billions who rely on the water for drinking supplies and irrigation.
He cited a recent report by a research center that said the level of the oceans is rising much faster than what was forecasted because of climate change. The UN chief stressed that unless nations are able to reverse this trend, because climate change for the moment is running faster than actions being taken by Governments, the research forecasted that 300 million people will be flooded by sea water in the world by 2050.
“Dramatically, the most vulnerable areas are exactly in Southeast Asia, in Japan, China, Bangladesh and India,” he said adding that Thailand risks to have 10 per cent of its population in flooded areas by the sea.