Is India’s thirst for fresh water causing ocean levels to rise? Experts warn that the backwaters of Kerala and the deltas of the Ganga, Krishna, Godavari, Cauvery and Mahanadi on the east coast are being threatened by rising ocean levels.
A recent Nasa study had confirmed that water tables in north India were declining at the rate of one foot per year across the northern states of India with even the ministry of water resources admitting that 109 cubic kilometres of water was lost from the aquifers along the Indus river alone.
Water expert Prof. Vikram Soni calculates that during the last 30 years, “India has lost close to thousand trillion tonnes of ground water which would have raised sea levels by one centimetre for this same period. Thirty per cent of the world’s ground water is being withdrawn from India alone Soni further points out.”
Overall, in the past five decades, several trillion tonnes of ground water has found its way into the ocean which is much more in scale than the melting of the two great ice caps, Greenland and Antarctica.
Prof. Yadu Pokhrel from the University of Tokyo has published a research in Nature Geoscience suggesting that groundwater is a major contributor to the observed sea level rise. The drawing of water from deep wells has caused the sea to rise by an average of a millimetre every year since 1961, researchers conclude.
India’s second National Communication to the UNFCCC has warned that sea level rise by 3.5 to 34.6 inches between 1990 and 2100 would result in saline coastal groundwater, endangering wetlands and inundating valuable land and coastal communities.
The study, using digital elevation model data (90m resolution), digital image processing and GIS software, showed that estimated inundation areas are 4.2 sq km and 42.5 sq km in case where the sea level rise is 1.0 m and 2.0 m respectively in the region surrounding Nagapattinam.
Experts express grave concern for climate change concluding that even if the climate were to get stabilised, sea levels would rise up to 10 metres or more if all the world’s groundwater was pumped out.