Climate Change and Sea Level Rise
Global climatic change induced by high concentration of carbon dioxide in the atmosphere that includes warmer climate, melting of glaciers, sea level rise, increase in incidences of tropical cyclonic storms, etc. are issues particularly relevant to Sundarban and other coastal areas of West Bengal. Amongst these, sea-level rise is the greatest threat and challenge for sustainable adaptation within such area. A 45 cm rise in global sea levels would lead to the destruction of 75 percent of the Sundarban mangroves. Along with global sea level rise, there is a continuous natural subsidence in the Sundarban, causing a rise of about 2.2 mm per year. The resulting net rise rate is estimated at 3.1 mm per year at Sagar. The consequences in terms of flooding of low-lying deltas, retreat of shorelines, salinitisation and acidification of soils, and changes in the water table raise serious concerns for the well being of the local population. Additional sources of stress, not related to climate change, include the diversion of upstream freshwater inflow of the Ganges by the Farraka Barrage in India since 1974 to alleviate the rapid siltation in the port of Kolkata. Jointly, the sea level rise and lower freshwater flow in winter will also result in increased salinity in the area, threatening the conservation of the Sundarban mangroves. The issues of climate change, therefore, constitute one of the major challenges of the 21st century and call for an integrated approach to issues of environmental preservation and sustainable development.