India's thirst adds to rising sea levels

India is pumping some 54 trillion litres of groundwater every year, enough to fill 21 million Olympic swimming pools, threatening a major water shortage and adding to already rising sea levels.

Researchers at the National Geophysical Research Institute in Hyderabad, India used gravity data from NASA’s Gravity Recovery and Climate Experiment (GRACE) to measure the loss of continental mass around the globe since 2002, reports NewScientist. The data has revealed that the groundwater under India is being depleted at an alarming rate and boreholes show the water table lowering by one foot per year. Northern India and its surrounding area is home to approximately 600 million people and is the most heavily irrigated region on the planet says Geophysical Research Letters. It's contribution to rising sea levels is comparable to that from melting Alaskan glaciers. The letters conclude that if groundwater is extracted faster than the aquifers can replenish for much longer that it will create major water shortages when the non-renewable resource has been exhausted. Matt Rodell, an NASA hydrologist has been looking at where this water is going since it doesn't just disappear. Rodell says that the water is being consumed by the human population of the region mainly for crop irrigation and "if measures are not taken to ensure sustainable groundwater usage, consequences for the 114 million residents of the region may include a collapse of agricultural output and severe shortages of potable water," reports NASA Earth Science News. Most of the water used runs back into the oceans which may be raising the sea levels by up to .16 millimeters per year or 5 per cent of the total rise of ocean levels.