Greenland ice sheet

Greenland ice sheet
Grønlands indlandsis
Sermersuaq
TypeIce sheet
Coordinates76°42′N 41°12′W / 76.7°N 41.2°W / 76.7; -41.2[1]
Area1,710,000 km2 (660,000 sq mi)[2]
Length2,400 km (1,500 mi)[1]
Width1,100 km (680 mi)[1]
Thickness1.67 km (1.0 mi) (average), ~3.5 km (2.2 mi) (maximum)[2]

The Greenland ice sheet is an ice sheet which forms the second largest body of ice in the world. It is an average of 1.67 km (1.0 mi) thick, and over 3 km (1.9 mi) thick at its maximum.[2] It is almost 2,900 kilometres (1,800 mi) long in a north–south direction, with a maximum width of 1,100 kilometres (680 mi) at a latitude of 77°N, near its northern edge.[1] The ice sheet covers 1,710,000 square kilometres (660,000 sq mi), around 80% of the surface of Greenland, or about 12% of the area of the Antarctic ice sheet.[2] The term 'Greenland ice sheet' is often shortened to GIS or GrIS in scientific literature.[3][4][5][6]

Greenland has had major glaciers and ice caps for at least 18 million years,[7] but a single ice sheet first covered most of the island some 2.6 million years ago.[8] Since then, it has both grown[9][10] and contracted significantly.[11][12][13] The oldest known ice on Greenland is about 1 million years old.[14] Due to anthropogenic greenhouse gas emissions, the ice sheet is now the warmest it has been in the past 1000 years,[15] and is losing ice at the fastest rate in at least the past 12,000 years.[16]

Every summer, parts of the surface melt and ice cliffs calve into the sea. Normally the ice sheet would be replenished by winter snowfall,[4] but due to global warming the ice sheet is melting two to five times faster than before 1850,[17] and snowfall has not kept up since 1996.[18] If the Paris Agreement goal of staying below 2 °C (3.6 °F) is achieved, melting of Greenland ice alone would still add around 6 cm (2+1⁄2 in) to global sea level rise by the end of the century. If there are no reductions in emissions, melting would add around 13 cm (5 in) by 2100,[19]: 1302  with a worst-case of about 33 cm (13 in).[20] For comparison, melting has so far contributed 1.4 cm (1⁄2 in) since 1972,[21] while sea level rise from all sources was 15–25 cm (6–10 in) between 1901 and 2018.[22]: 5 

If all 2,900,000 cubic kilometres (696,000 cu mi) of the ice sheet were to melt, it would increase global sea levels by ~7.4 m (24 ft).[2] Global warming between 1.7 °C (3.1 °F) and 2.3 °C (4.1 °F) would likely make this melting inevitable.[6] However, 1.5 °C (2.7 °F) would still cause ice loss equivalent to 1.4 m (4+1⁄2 ft) of sea level rise,[23] and more ice will be lost if the temperatures exceed that level before declining.[6] If global temperatures continue to rise, the ice sheet will likely disappear within 10,000 years.[24][25] At very high warming, its future lifetime goes down to around 1,000 years.[20]

  1. ^ a b c d Greenland Ice Sheet. 24 October 2023. Archived from the original on 30 October 2017. Retrieved 26 May 2022.
  2. ^ a b c d e "How Greenland would look without its ice sheet". BBC News. 14 December 2017. Archived from the original on 7 December 2023. Retrieved 7 December 2023.
  3. ^ Tan, Ning; Ladant, Jean-Baptiste; Ramstein, Gilles; Dumas, Christophe; Bachem, Paul; Jansen, Eystein (12 November 2018). "Dynamic Greenland ice sheet driven by pCO2 variations across the Pliocene Pleistocene transition". Nature Communications. 9 (1): 4755. doi:10.1038/s41467-018-07206-w. PMC 6232173. PMID 30420596.
  4. ^ a b Cite error: The named reference Noël2021 was invoked but never defined (see the help page).
  5. ^ Höning, Dennis; Willeit, Matteo; Calov, Reinhard; Klemann, Volker; Bagge, Meike; Ganopolski, Andrey (27 March 2023). "Multistability and Transient Response of the Greenland Ice Sheet to Anthropogenic CO2 Emissions". Geophysical Research Letters. 50 (6): e2022GL101827. doi:10.1029/2022GL101827. S2CID 257774870.
  6. ^ a b c Bochow, Nils; Poltronieri, Anna; Robinson, Alexander; Montoya, Marisa; Rypdal, Martin; Boers, Niklas (18 October 2023). "Overshooting the critical threshold for the Greenland ice sheet". Nature. 622 (7983): 528–536. Bibcode:2023Natur.622..528B. doi:10.1038/s41586-023-06503-9. PMC 10584691. PMID 37853149.
  7. ^ Thiede, Jörn; Jessen, Catherine; Knutz, Paul; Kuijpers, Antoon; Mikkelsen, Naja; Nørgaard-Pedersen, Niels; Spielhagen, Robert F (2011). "Millions of Years of Greenland Ice Sheet History Recorded in Ocean Sediments". Polarforschung. 80 (3): 141–159. hdl:10013/epic.38391.
  8. ^ Contoux, C.; Dumas, C.; Ramstein, G.; Jost, A.; Dolan, A.M. (15 August 2015). "Modelling Greenland ice sheet inception and sustainability during the Late Pliocene" (PDF). Earth and Planetary Science Letters. 424: 295–305. Bibcode:2015E&PSL.424..295C. doi:10.1016/j.epsl.2015.05.018. Archived (PDF) from the original on 8 November 2020. Retrieved 7 December 2023.
  9. ^ Knutz, Paul C.; Newton, Andrew M. W.; Hopper, John R.; Huuse, Mads; Gregersen, Ulrik; Sheldon, Emma; Dybkjær, Karen (15 April 2019). "Eleven phases of Greenland Ice Sheet shelf-edge advance over the past 2.7 million years" (PDF). Nature Geoscience. 12 (5): 361–368. Bibcode:2019NatGe..12..361K. doi:10.1038/s41561-019-0340-8. S2CID 146504179. Archived (PDF) from the original on 20 December 2023. Retrieved 7 December 2023.
  10. ^ Robinson, Ben (15 April 2019). "Scientists chart history of Greenland Ice Sheet for first time". The University of Manchester. Archived from the original on 7 December 2023. Retrieved 7 December 2023.
  11. ^ Reyes, Alberto V.; Carlson, Anders E.; Beard, Brian L.; Hatfield, Robert G.; Stoner, Joseph S.; Winsor, Kelsey; Welke, Bethany; Ullman, David J. (25 June 2014). "South Greenland ice-sheet collapse during Marine Isotope Stage 11". Nature. 510 (7506): 525–528. Bibcode:2014Natur.510..525R. doi:10.1038/nature13456. PMID 24965655. S2CID 4468457.
  12. ^ Christ, Andrew J.; Bierman, Paul R.; Schaefer, Joerg M.; Dahl-Jensen, Dorthe; Steffensen, Jørgen P.; Corbett, Lee B.; Peteet, Dorothy M.; Thomas, Elizabeth K.; Steig, Eric J.; Rittenour, Tammy M.; Tison, Jean-Louis; Blard, Pierre-Henri; Perdrial, Nicolas; Dethier, David P.; Lini, Andrea; Hidy, Alan J.; Caffee, Marc W.; Southon, John (30 March 2021). "A multimillion-year-old record of Greenland vegetation and glacial history preserved in sediment beneath 1.4 km of ice at Camp Century". Proceedings of the National Academy of Sciences. 118 (13): e2021442118. Bibcode:2021PNAS..11821442C. doi:10.1073/pnas.2021442118. ISSN 0027-8424. PMC 8020747. PMID 33723012.
  13. ^ Gautier, Agnieszka (29 March 2023). "How and when did the Greenland Ice Sheet form?". National Snow and Ice Data Center. Archived from the original on 28 May 2023. Retrieved 5 December 2023.
  14. ^ Yau, Audrey M.; Bender, Michael L.; Blunier, Thomas; Jouzel, Jean (15 July 2016). "Setting a chronology for the basal ice at Dye-3 and GRIP: Implications for the long-term stability of the Greenland Ice Sheet". Earth and Planetary Science Letters. 451: 1–9. Bibcode:2016E&PSL.451....1Y. doi:10.1016/j.epsl.2016.06.053.
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  16. ^ Cite error: The named reference Briner2020 was invoked but never defined (see the help page).
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  19. ^ Fox-Kemper, B.; Hewitt, H.T.; Xiao, C.; Aðalgeirsdóttir, G.; Drijfhout, S.S.; Edwards, T.L.; Golledge, N.R.; Hemer, M.; Kopp, R.E.; Krinner, G.; Mix, A. (2021). Masson-Delmotte, V.; Zhai, P.; Pirani, A.; Connors, S.L.; Péan, C.; Berger, S.; Caud, N.; Chen, Y.; Goldfarb, L. (eds.). "Chapter 9: Ocean, Cryosphere and Sea Level Change" (PDF). Climate Change 2021: The Physical Science Basis. Contribution of Working Group I to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change. Cambridge University Press, Cambridge, UK and New York, NY, US. Archived (PDF) from the original on 24 October 2022. Retrieved 22 October 2022.
  20. ^ a b Cite error: The named reference Aschwanden2019 was invoked but never defined (see the help page).
  21. ^ Cite error: The named reference Mouginot2019 was invoked but never defined (see the help page).
  22. ^ IPCC, 2021: Summary for Policymakers Archived 11 August 2021 at the Wayback Machine. In: Climate Change 2021: The Physical Science Basis. Contribution of Working Group I to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change Archived 26 May 2023 at the Wayback Machine [Masson-Delmotte, V., P. Zhai, A. Pirani, S.L. Connors, C. Péan, S. Berger, N. Caud, Y. Chen, L. Goldfarb, M.I. Gomis, M. Huang, K. Leitzell, E. Lonnoy, J.B.R. Matthews, T.K. Maycock, T. Waterfield, O. Yelekçi, R. Yu, and B. Zhou (eds.)]. Cambridge University Press, Cambridge, United Kingdom and New York, NY, US, pp. 3–32, doi:10.1017/9781009157896.001.
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