During the 25th UN Climate Change Conference in Madrid, we showed the readers of ZEIT ONLINE climate change right on their doorstep. Using fine grid data from the German Weather Service, we were able to calculate for the first time how the temperature in every community in Germany has changed over the past 137 years. For the presentation we use so-called “Warming Stripes”, heat strips inspired by the British scientist Ed Hawkins. They show how warm or how cold a year was compared to the internationally established reference period 1961-1990. The article is in German but can be seen translated
We could show that nine of the ten hottest years were after the turn of the millennium. We were also able to calculate that Germany has warmed up by an annual average of about 1.5 degrees Celsius since records began in 1881. If the global climate had warmed up that much, we would already have missed one of the goals of the Paris Climate Convention. Finally, we show the readers in which climate zone their home town is located and how strong the warming was exactly there.
Our readers shared the heat strips from their community in the social media. We offered a special function for this. In addition, the Federal Environment Ministry took up our presentation and published a corresponding graphic. The article was also taken up in presentations such as at the Chaos Computer Congress.
To batch download, analyze and convert the data we used a lot of command line tools such as GDAL and rasterstats. To verify our analysis we also used QGIS and Zonal Statistics. In the frontend, the project was implemented with React and D3.
What was the hardest part of this project?
Dealing with scientific data at this large scale we talked to as many experts as possible in order to get everything perfectly right. In order to anticipate critics, in addition to the detailed methodology, we have made all calculations, scripts and data available on Github (https://github.com/ZeitOnline/waermestreifen-gemeinden-scripts) so that the results can be reproduced.
What can others learn from this project?
Maximum transparency is key to anticipate critics. In case of critical questions about our article we could always refer to the reproducible scripts we published.