Week 1: Oceans and Climate > Topic 1e - Sea level rise (part 1): overview with Dr Anny Cazenave

Altimetry has been measuring the sea levels, over all the oceans since the early 1990s.

By averaging these levels over the oceans, and looking at the variations on the whole period, one can estimate the global sea level rise with an accuracy of 0.5 mm/yr.

Sea levels across the globe are on the rise due to global climate change, and even a small, permanent increase in the global sea level could have major consequences for the Earth’s populations - particularly for those situated in coastal regions.

Sea level is one of the Essential Climate Variables, and an indicator closely monitored by the IPCC.

Optional mini task:

Explore the altimetry sea level data here. From looking at a number of different altimetry sensors on the interactive graph, how has sea level changed over recent years? How do the trends vary between different sensors and different zones?

Featured Educators:

Explore the data

EUMETSAT Oceans MOOC Data Viewer

Optional further reading

View featured satellites on the satellite tracking app

To download the video above please click the ‘Download video’ button located on the top-right.

You can download the video transcript pdf below onto your computer by opening the document, right-clicking and selecting the save option.

View featured imagery, animations and external links below


The sea surface height animation is compiled from the global ocean gridded near-real-time sea level anomaly product, produced by the Copernicus Marine Environment Monitoring Service (CMEMS).

This image is a model of the ‘geoid’ created by ESA’s GOCE mission. It is the most accurate model of the ‘geoid’ ever produced, which will be used to further our understanding of how Earth works.

The colours in the image represent deviations in height (–100 m to +100 m) from an ideal geoid. The blue shades represent low values and the reds/yellows represent high values.

Sea level trends were estimated using data from TOPEX/Poseidon (T/P), Jason-1, and Jason-2, which have monitored the same ground track since 1992.

Illustration of how altimetry measurement works for Jason satellite

Global mean sea level change graph 1992-2016

Regional sea level change graph

Sea level anonomalies in the Gulf Stream from Sentinel-3, Jason-3, Jason-2, Cryosat-2, and SARAL/AltiKA data