Sea levels off Shanghai and other Chinese coastal cities are rising at an alarming rate, leading to contamination of drinking water supplies and other threats, China's State Oceanic Administration reported Thursday.
Waters off the industrial port city of Tianjin, 60 miles southeast of Beijing, rose by 7.72 inches over the past three decades, the administration said.
Seas off the business hub of Shanghai have risen by 4.53 inches over the same period, the report said.
Administration experts said global climate change and the sinking of coastal land due to the pumping of ground water were the major causes behind rising water levels.
"Sea level rises worldwide cannot be reversed, so Chinese city officials and planners must take measures to adapt to the change," Chen Manchun, an administration researcher, was quoted as saying on the central government's official Web site.
Globally, rising seas threaten to submerge low-lying island groups, erode coastlines and force the construction of vast new levees. Some scientists have warned that melting of the vast glaciers of Greenland could cause a 13-foot rise in sea levels in coming centuries.
Higher sea levels and sinking land caused by dropping water table levels complicate Shanghai's already difficult task of providing safe water supplies to its 20 million people due to salt water leaching into its aquifer, the administration said.
Along China's 11,185 miles of coastline, sea levels have risen by an average of 3.54 inches, while average coastal water temperatures were slightly warmer, the report said.
Waters levels have risen more quickly in the country's north, the report said, but gave no reasons for the disparity.
Meanwhile, the administration's China 2007 Sea Environmental Quality Report, also released this week, showed a marked deterioration in coastal water quality as a result of pollution from human activity onshore.