Coastal and marine ecosystems are among the most productive ecosystems of the State and include backwaters, estuaries, mangroves, mudflats, sand dunes, seaweed ecosystems and the extensive coastal waters which cover near shore coastal areas (backwaters in Kerala, including Kuttanad Wetland) and open ocean marine areas. The Coastal Zone in Kerala is the low land fringing the sea extending over 590 km (about 10 per cent of the coastline of India), with a height of less than 8 m from the Mean Sea Level (MSL), covering about 15 % of the State’s total area of 38,863 sq km.

• Coastal systems are particularly sensitive to three key drivers related to climate change: sea level, ocean temperature and ocean acidity.
• The coastal areas, especially the low lying areas in the state such as Kuttanad, may experience adverse impacts such as submergence, coastal flooding and coastal erosion due to relative sea level rise. This will further impact the water security and food production in the coastal habitats.
• The highly productive ecosystems along Kerala coast, including mangroves and sea weed ecosystems would also be impacted by the climate change.
• The sea level rise recorded in Indian seas during 1970-2010 was more than and the projection for 2050 and 2100 are more than 20 to 40 and 50 to 70 cm respectively. Under the influence of climate change, beaches, sand dunes and cliffs currently eroding will continue to do so under increasing sea level.
• The human settlements (especially those of the fisher folks), transportation and tourism infrastructure at or near the coast is vulnerable to more frequent flooding, rising sea levels and possible increase in the magnitude and frequency of tropical storms and other natural calamities due to climate change.
• Temperature is known to affect fish distribution and migration; the combined effects of changes in distribution, abundance and physiology may reduce the body size of marine fishes, particularly in the tropics and intermediate latitudes.
• Coral reefs are the most diverse, biologically complex and economically important marine ecosystems on earth. The reef building scleractinian corals are currently facing multiple stresses caused by shifts in the marine environment associated with global warming, ocean acidification, sedimentation, pollution and eutrophication.
• The extreme runoff in seasons of South West and North East monsoon in Kerala is bound to affect timing, frequency, and severity of flash floods, subsequently disrupting ecosystems more than changes in mean conditions. These floods may influence the streams through erosion and sedimentation, the distribution of macrophytes as well as primary production.