A study by Tamil Nadu State Land Use Research Board, along with Indo-German Centre for Sustainability and IIT Madras, has estimated that in the next three decades, Chennai could witness a rise of sea between 4.35 metres and 6.85 metres due to tropical cyclones affecting 1,963 square km of land mass.

The report warned that Tamil Nadu is vulnerable to storm surges and sea level rise, as it has yet to come up with a comprehensive coastal management plan as mandated under Coastal Regulation Zone (2011) rules.

As per the Ministry of Environment and Forest notification of CRZ Rules, Tamil Nadu State Coastal Zone Management authority (SCZMA) was to manage coastal zones of the state and come out with Coastal Management Rules. This, however, is yet to materialise.

The report urged the Union government to implement Integrated Coastal Zone Management (ICZM) in Tamil Nadu under the second phase so that the State could identify best practices of the integrated approach, now being implemented in Odisha and Gujarat in the first phase, and restructure the TNSCZMA to address sea level rise.

The study stated that the eastern coast of India is more vulnerable due to its low-lying nature. “Most of the infrastructure including ports and roads had not been conceptualised and implemented by factoring in impact of climate change, especially sea level rise during their construction,” the study observed.

The report called for continuous monitoring of sea level and erosion along the State’s coastline as an immediate measure by the State and the Coastal Protection and Development Advisory Committee of the Central Water Commission, the National Centre for Earth Science Studies, Indian National Centre for Sustainable Coastal Management, Survey of India and National Centre for Sustainable Coastal management.

The 2016 Vardah cyclone, which made a landfall close to Chennai Coast, resulted in storm surge (sea rise) of 20 feet. The cyclone resulted in inundation of coastal areas. The report, which had undertaken the study of entire Chennai Coast has, predicted two scenarios — when the sea level would rise by one metre and the more disastrous second scenario where it rises by three metres.

The difference is startling. If the sea rises by a metre, 38.2 sq km of built-up area including residential, commercial and industrial areas will be affected. But if it is to rise by three metres, the impact would be felt for 101.96 sq km of built up area, the study cautioned.

The report strongly criticised the Tamil Nadu State Climate Cell, which was set up by department of environment in 2014.

“A major mission of the cell was to establish a platform to collect, collate, disseminate climate change information to various stake holders, ranging from farmers, fishermen, general public to policy planners, decision makers, bureaucrats and others in order to enable effective climate change governance and services in the State,” the report observed.