The graph below is derived from coastal tide and satellite data. It shows how much sea level changed from about 1870 to 2018. Items with pluses (+) are factors that cause global mean sea level to increase, while minuses (-) are variables that cause sea levels to decrease. These items are displayed at the time they were affecting sea level. Graph shows sea levels starting in 1900 and includes events that lead to increases and decreases in sea level. In 1900, sea level change is set to zero. In 1920, sea level rose 20 millimeters. In 1940, sea level rose to 50 millimeters. In 1960, sea level rose to 100 millimeters. In 1980, sea level rose to 125 millimeters. In 2000, sea level rose to 150. By 2020, sea-level rises 200 millimeters. © 2021 NASA's Goddard Space Flight Center According to the graph, melting ice sheets and glaciers combined with thermal expansion as factors increasing sea level rise. What additional variable may have caused the rate of sea level rise between 2000 and 2020? More global dams Refreezing Arctic Ocean circulation Cooler Antarctic