scibri writes "During the latter half of the twentieth century, global sea level rose by about 1.8 millimeters per year. The combined contribution from heating of the oceans, which makes the water expand, along with melting of ice caps and glaciers, is estimated to be 1.1 millimeters per year, which left some 0.7 millimeters per year unaccounted for. It seems that the effects of human water use on land could fill that gap. Researchers report in Nature Geoscience that land-based water storage could account for 0.77 millimeters per year, or 42%, of the observed sea-level rise between 1961 and 2003. The extraction of groundwater for irrigation and home and industrial use, with subsequent run-off to rivers and eventually to the oceans, represents the bulk of the contribution. It would be even worse if we weren't also locking up lots of water from rivers behind dams like the Hoover Dam."