Consequences of climate change: Germany is slowly drying out

Germany is still blessed with plenty of water. That is taken for granted. But new data shows that the water loss is considerable – and the extent is not yet foreseeable.

You can see some things better from above. Jay Famiglietti, Director of the Global Institute for Water Security at the University of Saskatoon, Canada, is evaluating data from the Grace satellites on behalf of NASA and the German Aerospace Center. And his results – you can hear – make him concerned. “To put it plainly: Germany has lost water by the size of Lake Constance in 20 years. That’s an unimaginable amount of water.”

For almost 20 years, the two Grace satellites have been measuring changes in the earth’s gravity, which are caused by the different water content, for example, almost to the day. “The evaluation of the data shows us the negative trend,” says Famiglietti. “The water loss in Germany is about 2.5 gigatons or cubic kilometers per year. This makes it one of the regions with the highest water loss in the world.”

Everywhere in Germany less water

A frightening finding. Famiglietti only establishes the facts, he does not speculate about the causes. But other analyzes show that climate change is at the forefront. On the one hand, higher temperatures lead to more evaporation, on the other hand, more water simply flows away during heavy rain events and does not even reach the groundwater bodies.

While the data from the Grace satellites have a relatively coarse grid – their results are presented in squares 150 kilometers on a side – but even so, one can see certain regional differences, explains Famiglietti. “And if you look closely, you can see that there is a particularly high level of water receding in the region around Lüneburg, as well as in the south-west, in Baden-Württemberg, and in the south-east, in Bavaria.” However, practically all of Germany is red, and that means less water everywhere.

High consumption by agriculture and private households

This is particularly problematic in periods of acute drought. The effects were already noticeable in the past summers: During prolonged dry periods – like in the summer of 2018 – there were already regional problems with the public water supply. In the fields the plants withered and in the forests the trees suffered badly.

Agriculture is both a perpetrator and a victim. In their distress, the farmers seek their salvation in more and more irrigation. But private households are also fighting the drought with plenty of water, even if it only causes their lawns to dry out.

Hydrologists call for precautionary measures

These are still problems that occur in individual years or in individual locations. But the hydrologist Prof. Martin Grambow, chief water economist at the Bavarian Ministry of the Environment, warns in view of the data from the Grace mission: “There are things that have not yet been published by us, but which unfortunately all support this picture. That we ultimately have a systemic Have a deficit. And the unpleasant thing about it is that it goes well for a long, long time. And when it becomes noticeable, it’s far too late.”

Hydrologists are therefore calling for precautions to be taken now. New water catchment areas would have to be protected. And larger supply networks could ensure that the increasingly scarce resource of water will still be available everywhere decades from now. But while supply is becoming scarcer, water consumption has risen again in recent years.