09 May 2012: Groundwater Pumping Emerges
As a Factor in Sea Level Rise, Study Says

The vast amounts of water pumped out of the ground for irrigation, drinking water, and industrial uses will increasingly contribute to global sea level rise in the coming decades, according to a new study. According to researchers at Utrecht University, humans pumped about 204 cubic kilometers (49 cubic miles) of groundwater in 2000, much of which evaporated into the atmosphere before ultimately entering rivers, canals and, eventually, the world’s oceans. While in earlier decades the rise in sea level caused by groundwater removal was canceled out by the construction of dams, that changed by the 1990s as humans pumped more groundwater and built fewer dams. By 2000, groundwater extraction resulted in a sea level rise of about 0.57 millimeters annually — compared with about 0.035 millimeters in 1990. According to the study, published in the journal Geophysical Research Letters, by 2050 the pumping of groundwater worldwide could cause sea levels to rise about 0.8 millimeters annually. “Other than ice on land, the excessive groundwater extractions are fast becoming the most important terrestrial water contribution to sea level rise,” said Yoshihide Wada, a researcher at Utrecht University and lead author of the study.