Rising sea level- a threat to coastal areas

Rising sea level- a threat to coastal areas

Subject: Environment

Section: Climate Change

Context: An increase in sea level as a result of global warming, according to data, poses athreat to millions of coastal dwellers across the world.

• States such as Gujarat, Tamil Nadu and West Bengal have been witnessing rapid coastal erosion and face greater risk.
• The Global Mean Sea Level (GMSL) reached a new record high in 2021, increasing at an average 4.5 mm per year over the period 2013 -2021.
• This is more than double the rate at which sea levels rose between 1993 and 2002.
• GMSL integrates changes occurring in many components of the climate system, these include ocean warming via thermal expansion of seawater, melting of land ice and exchange of water with water bodies on land.

Rise not uniform

• Although the sea level has risen almost everywhere since 1993, it has not risen equally everywhere.
• Several regions continue to be affected by a rate of sea-level rise substantially faster than the global mean which shows the difference between local and global sea levels.
• This is particularly the case in the western Tropical Pacific, the Southwest Pacific, the North Pacific, the South-west Indian Ocean and the South Atlantic.

Affect on Indian coasts

• National Centre for Coastal Research (NCCR), Chennai under Ministry of Earth science is monitoring shoreline erosion since 1990 using remote sensing data and GIS mapping techniques.
• The approximately 6,907.18 km long Indian coastline of the mainland has been inspected from 1990 to 2018, and it has been noted that about 34 percent of the coastline is facing erosion in varying degrees.
• West Bengal has reported the highest 60.5 percent erosion followed by Puducherry (56.2 percent).
• The 15th Finance Commission has suggested that the National Disaster Management Authority and or Ministry of Home Affairs develop suitable norms as mitigation measures to prevent erosion, and that the Union and States develop a policy to deal with the extensive displacement of people due to coastal and river erosion.