The study conducted by Centre for Development Finance said, "A one metre rise in average sea level would permanently inundate about 1091 sq km along Tamil Nadu coast, but the total area at risk would be nearly six times as much."
Focussing on financial implications of the existing and proposed infrastructure on the coastline the report said, sea level rise (SLR) arising out of climate change "will affect the coastline in a variety of ways, including inundation, flood and storm water damage and salt water intrusion and wetland loss."
Certain areas in five coastal districts in the state - Tiruvarur, Thanjavur, Pudukottai, Nagapattinam and Ramanathapuram - were estimated to be at risk from one metre SLR, because of very high storm surges that already affect them, it said.
The study further estimated the total replacement value of infrastructure (ports, power plants) in financial terms, putting it between Rs 47,000 and Rs 53,000 crore.
"The present value of wetlands impacted by SLR is estimated between Rs 3583 crore and Rs 14,068 crore," it said.
Sujatha Byravan, lead author of the report, said while thousands of crores of investment was being made along the coastal cities in the country, there was a need to take into consideration the sea level rise and need to protect wetlands.
Among its recommendations, the study has called for comprehensive vulnerability assessment, integration of climate change considerations and coastal protection measures such as early warning systems and providing assistance to "at risk communities."