For our project "Rising Seas" we analysed data that was recorded for decades at measuring stations worldwide. We want to share this knowledge. Other media, journalists and bloggers are welcome to use and spread our findings.

Our research started with a simple question: Is climate change already impacting the world’s coastlines? It was a monthly project, in which CORRECTIV cooperated with scientists and journalists around the world. French online investigative website Mediapart participated, as well as colleagues from Columbia University in the USA, and journalists in Iceland, Switzerland and the Philippines. The resulting stories have been published in South Korea, the USA, France, Switzerland, and Germany.

We want as many people as possible to find out about the results. Any newspaper, blog, or online site can publish and distribute the data and articles. The only condition is that CORRECTIV is cited as the source and the article links to

We found the answer to our original question in sea level measurements. For more than a century sea levels have been monitored. Originally the measurements were taken using a level plate fixed to the walls of ports worldwide, and were used to navigate ships safely into ports. Today, pressure probes or ultrasound equipment record the data.

The most comprehensive dataset is held by the UK’s Permanent Service for Mean Sea Level (PSMSL). Their database includes recordings from 2,000 measuring stations around the world.

Our analysis quickly found that some stations had only operated for a few years, or had incomplete measurements. Different measuring stations also began and finished recording at different times.

We had to set rules to get a consistent record. After many discussions with scientists, we arrived at the following criteria: Data from a measuring station was only used if at least 70 per cent of measurements between 1985 and 2015 were available. Flawed measurements were removed from the dataset. The dataset includes 513 stations and some 34,000 measurement points.

Unfortunately there are only a few measuring stations in the southern hemisphere. There are only a few measuring stations on our visualisation for Africa, South America and parts of Asia. There are fewer measurements in these regions because there was no significant global trade traffic for a long time.

Despite these limitations, the results of our work are remarkable. For the first time, we can see how the sea level has changed in recent decades on a world map.

It’s clear: The sea level is rising worldwide. Climate change is in full swing.



Important contacts

Jürgen Jensen, Head of the Department of Hydromechanics at the University of Siegen,, +49 271 740-2172

Anders Levermann, climate researcher in Potsdam and New York,, Tel +49 331 288 2560

Otmar Edenhofer, Director of the Potsdam Institute for Climate Impact Research,, Tel +49 331 288 2565


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