Sea level rise
Global average sea level has risen 24 cm since 1850. Projections suggest that, by 2100, global mean sea level will rise between 54 cm under a “Paris Agreement” (RCP4.5) climate scenario and 74 cm under a “business-as-usual” (RCP8.5) climate scenario. Current sea-level research with GEUS focuses on understanding both the causes of sea-level rise, as well as regional variability in sea-level rise.
There are many causes of sea-level rise. Thermal expansion of seawater, or the decrease in water density as it warms, is a major source of sea-level rise. However, transferring land-ice, such as glaciers and ice sheets, into the ocean is the single biggest cause of recent sea-level rise. Dwindling Arctic land ice is responsible for 48% of global mean sea-level rise since 1850, with the Greenland ice sheet alone responsible for 11% of post-1850 sea-level rise. Recent Greenland ice loss is driven by both the runoff of liquid meltwater, and the discharge of solid icebergs. The ice loss caused by these processes, which changes through space and time, is assessed using a combination of satellite measurements, climate models, and in-situ observations.