Since the early 1990s, the rate of sea level rise has been increasing. By the early 1990s, it was about 2.5 mm per year. Over the past decade, the rate has increased to 3.9 mm (0.15 inches) per year. The observations have confirmed on a global scale what scientists previously saw from the shoreline: the seas are rising, and the pace is quickening. Scientists have found that global mean sea level has risen 10.1 centimeters (3.98 inches) since 1992. Over the past 140 years, satellites and tide gauges together show that global sea level has risen 21 to 24 centimeters (8 to 9 inches). The rise in global sea levels has accelerated since the 1990s amid rising temperatures, with a thaw of Greenland's ice sheet pouring ever more water into the oceans. The annual rate of sea level rise increased to 3.3 millimeters (0.13 inch) in 2014 - a rate of 33 centimeters (13 inches) if kept unchanged for a century - from 2.2 mm in 1993.