Lakhs of crore worth infrastructure at risk due to sea level rise: Study

(published)

Chennai:

More than lakhs of crore worth infrastructure would be hit across the Tamil Nadu coast if the sea level rises by one metre by 2050, according to a study done by Center for Development Finance (CDF).

The study says based on the preliminary estimates the rise in sea level will pose a risk to major infrastructure, wetlands and land worth 3.68 lakh crore to 61.83 lakh crore in the coastline of Tamil Nadu which is dotted by ports, nuclear and thermal planrs and special economic zones besides industries.

Interestingly, there are different opinions on when the sea level will rise. While noted scientist M S Swaminathan in a lecture delivered at National Institute of Ocean Technology warns that sea level will rise by the end of the century, the authors of the study --- Sujatha Byravan, a senior researcher at CDF, Prof  Sudhir Chella Rajan of Indian Institute of Technology, Madras, humanities and social sciences department and Rajesh Rangarajan, senior researcher at CDF, maintain the sea level will rise by one metre by 2050.

Sujatha and Prof Rajan said that they arrived at the figure of 2050 based on the prediction of sea level rising by several metres by 2100 and the current estimate is based on the low end of the estimates, that is one metre. “The glaciers are melting and Antarctica is losing ice at an accelerating rate. We expect the sea level to rise much sooner,” they added.

However, the study does provide an insight into the financial impact of a possible sea level rise of one metre on the economy of the state. “The area at risk from a one metre sea level rise (SLR) is estimated on the basis of district level analyses of the likely impact of storm surges. Five coastal districts – Nagapattinam, Thiruvarur, Thanjavur, Pudukotai and Ramanathapuram, which is below 10 meter above current mean sea level is estimated to be at risk from a one metre SLR,” the authors say.

They also believe the one metre surge in sea level will permanently inundate 1,091 square km along the Tamil Nadu coast and the total risk would be six times more than that.

The study estimates the total replacement value of infrastructure (ports, power plants and major roads) impacted by sea level rise to be between 47,418 crore and Rs 53,554 crore (in 2010 terms). The present value of wetlands (estimated in terms of foregone ecosystem services by 2050) impacted by sea level rise is estimated between Rs 3,583 crore and Rs 14,608 crore and land, whose market value is estimated to be between Rs 3.17 lakh crore and 61.15 lakh crore.

While the study did not use detailed geomorphical analysis and modeling of coastline to provide precise estimates, it relied on information on infrastructure location and investments. Geographic Information System baseline information was taken from sources such as LandSat7 and OpenStreet-Maps as well as government agency websites.

The study also recommends comprehensive vulnerability assessment of the entire coast besides integrating climate change considerations into coastal infrastructure and protecting wetlands.