Sea Levels & Ice
Satellite-measured sea level rise, Arctic and Antarctic sea ice extent since 1979, global ice anomalies, and ocean surface warming – tracking the clearest physical consequences of a changing climate.
Fetching live climate data...
FAQs
FAQs
What does the sea levels and ice page show?
Live indicators of how Earth's ice and oceans are responding to warming: global mean sea level from satellite altimetry, Arctic and Antarctic sea-ice extent, and Greenland and Antarctic ice sheet mass change. Current values and long-term trends are shown in the live panels above.
What is the difference between sea ice and land ice?
Sea ice is frozen sea water floating on the ocean (Arctic and Antarctic). Its extent changes each year between summer and winter, and shrinking sea ice does not directly raise sea level because it is already displacing water. Land ice (the Greenland and Antarctic ice sheets, plus mountain glaciers) sits on land - when it melts it adds new water to the ocean and is the main driver of long-term sea level rise alongside thermal expansion.
Where does the data come from?
Sea level: NASA satellite altimetry (TOPEX/Poseidon, Jason and Sentinel missions) and the tide-gauge network. Sea ice: National Snow and Ice Data Center (NSIDC), based on NOAA passive microwave satellite observations. Ice sheet mass: GRACE and GRACE-FO satellite missions, archived by NASA JPL.
What baseline is used for the anomalies?
Sea ice anomalies use the 1981-2010 reference period (NSIDC standard). Sea level anomalies use a 1993-2008 satellite-altimetry reference. Ice-mass change is reported as cumulative gigatonnes lost since the start of each satellite record. The baseline is labelled on each chart.
How often is this page updated?
Sea-ice extent feeds refresh daily during the melt and freeze seasons. Sea level and ice-mass data refresh monthly as the source agencies release new processed values, typically with a one- to two-month lag.