For our project Rising Seas, we analyzed data about sea levels recorded over decades in hundreds of coastal regions worldwide. Our research started with a simple question: Has climate change already impacted the world’s coastlines?
We found the answer to our question in sea level data from a global network of tide gauges that have been used to measure mean sea levels for decades. Originally, the measurements were taken using level plates fixed to the walls of ports worldwide, and were used to navigate ships safely into ports. Today, sensors such as pressure probes or ultrasound equipment record the data.
Based on this historical data, we can see how the sea level has changed over the decades on a world map. It’s clear: The sea level is rising worldwide. Climate change is in full swing. Our data analysis shows how a rise in temperatures by only one degree celsius has already changed coasts around the world.
This investigation was a long term project, in which CORRECTIV cooperated with scientists and journalists around the world. Contributors included staff and students from Columbia University in NYC, as well as journalists in Iceland, Switzerland, France, and the Philippines. The resulting stories have been published in South Korea, the USA, France, Switzerland, and Germany.
Based on initial results from our data analysis, we gathered individual stories, researched by us and by our partners around the world. In addition to these stories, we made the data available online in a data explorer app that allows users to find the information we have for each country and to see the data – both visualized on a map and in charts. We also added more information for context, such as carbon dioxide emissions and data on the risks for the coastal population.
What makes this project innovative?
Based on this data, we built a news app that lets users browse the data themselves and provides context for them to understand how the issue of rising seas relates to them.
This a collaborative project. Not only have we worked with partners in different countries, other journalists can download the cleaned-up data from the news app to do their own analyses or use the source code for this project, which is published publicly on GitHub.
What was the impact of your project? How did you measure it?
Source and methodology
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 percent of measurements between 1985 and 2015 were available. Stations with flawed measurements were removed from the dataset. The final dataset includes 513 stations and some 34,000 measurement points.
One problem with the data is that there are only a few measuring stations in the southern hemisphere. That means that there is very little data in our news app for Africa, South America and parts of Asia. There are fewer measurements in these regions because measurements are usually done in commercial ports. For regions without global trade traffic there is no data.