changes that can be attributed to either the natural Atlantic Multidecadal Oscillation (AMO) or to anthropogenic climate change. A 2005 report indicated that the Atlantic meridional overturning circulation (AMOC) slowed down by 30% between 1957 and 2004. If the AMO were responsible for SST variability, the AMOC would have increased in strength, which is apparently not the case. Furthermore, it is clear from statistical analyses of annual tropical cyclones that these changes do not display multidecadal cyclicity. Therefore, these changes in SST must be caused by human activities. The ocean mixed layer plays an important role in heat storage over seasonal and decadal time-scales, whereas deeper layers are affected over millennia and have a heat capacity about 50 times that of the mixed layer. This heat uptake provides a time-lag for climate change but it also results in thermal expansion of the oceans which contributes to sea level rise. 21st-century global warming will probably result in an equilibrium sea-level rise five times greater than today, whilst melting of glaciers, including that of the Greenland ice-sheet, expected to have virtually no effect during the 21st century, will probably result in a sea-level rise of 3–6 m over a millennium. See also List of countries and territories bordering the Atlantic Ocean List of rivers of the Americas by coastline#Atlantic Ocean coast Seven Seas Gulf Stream shutdown Shipwrecks in the Atlantic Ocean Atlantic hurricanes Atlantic history Piracy in the Atlantic World Transatlantic crossing Atlantic Revolutions Natural delimitation between the Pacific and South Atlantic oceans by the Scotia Arc References Sources map Further reading External links Atlantic Ocean. Cartage.org.lb (archived) "Map of Atlantic Coast of North America from the Chesapeake Bay to Florida" from 1639 via the Library of Congress Oceans Articles containing video clips Oceans surrounding Antarctica