Greenland glaciers and sea level

Brief published by CNRS-INSU - November 18, 2020

The three Greenlandic glaciers Jakobshavn Isbræ, Kangerlussuaq and Helheim are the most important contributors to Greenland’s mass loss. However, they alone contain enough ice to raise the global sea level by 1.3 m, if they were to disappear completely. }

An international team used historical photographs to calculate the amount of ice lost by these glaciers between 1880 and 2012, a period during which the average temperature of the atmosphere in these regions had increased by about 1.5ºC. The scientists estimated that the Jakobshavn Isbræ Glacier lost a total mass of about 1,518 gigatons (or 1,012 kg) during this period, while between 1900 and 2012, the Kangerlussuaq Glacier lost 1,381 gigatons and the Hellheim Glacier only 31 gigatons. This loss of mass resulted in a sea level rise of 8.1 mm [1] during the 20th century.

Current modeling results indicate that, under the IPCC worst-case scenario (RCP 8.5), the loss of mass from these three glaciers could contribute to a sea level rise of 9.1 to 14.9 mm by 2100.
However, in this scenario, temperatures in Greenland could have increased by 8.3°C in 2100 (compared to the average temperature value between 1986 and 2005) due to polar amplification, about five to six times more than what happened from 1880 to 2012. Based on their results, the researchers therefore estimate that the loss of ice from the three glaciers could in fact far exceed current projections for this scenario.

Learn more

Khan et al. 2020, https://www.nature.com/articles/s41467-020-19580-5

Local Scientific Contact

Jérémie Mouginot, glaciologist at the IGE, CNRS

This brief has been published by CNRS.