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Global Climate Change - Mean sea level

Global Climate Change
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Mean sea level

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Under the effect of global warming, sea level will rise mainly due to two processes. Firstly, oceans warm and expand. Secondly, melting of glaciers, ice caps and the Greenland and Antarctic Ice Sheets will raise the sea level.

The average rate of global mean sea level rise was 1.3 mm yr-1 between 1901 and 1971, increasing to 3.7 mm yr-1 between 2006 and 2018. Global mean sea level has risen faster since 1900 than over any preceding century in at least the last 3,000 years.

Changes in global mean sea level based on various datasets

Changes in global mean sea level based on various datasets (Image credit: IPCC AR6)


In the satellite altimetry era, the average rate of sea level rise has more than doubled, increasing from 2.13 mm yr-1 (1993-2002) to 4.77mm yr-1 (2014-2023).

Global mean sea level evolution based on satellite altimetry

Global mean sea level evolution based on satellite altimetry (mm)
The black line is the best estimate, and the grey shaded area represents the uncertainty. (Image credit: WMO/AVISO altimetry)

 

Image credit:

Figures 2.28 (b) and (c) from Gulev, S. K., P. W. Thorne, J. Ahn, F. J. Dentener, C. M. Domingues, S. Gerland, D. Gong, D. S. Kaufman, H. C. Nnamchi, J. Quaas, J. A. Rivera, S. Sathyendranath, S. L. Smith, B. Trewin, K. von Shuckmann, R. S. Vose, 2021, Changing State of the Climate System. 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 [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. In Press.