Climate changes Germany's coast

At the moment, water levels in Germany's North and Baltic Seas are not rising any faster than usual, but scientists say the process is likely to speed up in the coming decades. Exactly when, and by how much, is uncertain. And that complicates the work of coastal defense authorities.

Over the centuries, the hundreds of kilometers of dikes along Germany's coastline have become higher and more sophisticated. The latest incarnations are called "climate dikes" and are especially designed to be able to hold back higher waters brought about by warming temperatures and rising sea levels.

One time-honored way populations under threat from higher sea levels have sought to secure themselves, has been to build their homes on small mounds. On the so-called Hallig islands, it is not uncommon for these embankments to be all that is left above water during a storm surge.

Unlike sea-level rise, an increase in temperatures in Germany's North and Baltic Seas is already palpable. Scientists say both bodies of water are around 1 degree Celsius (1.8 degrees Fahrenheit) warmer than in the 1960s. This shift in conditions has had an impact on several species, including cod, which have begun to migrate north in search of the cold in which they thrive.

At the other end of the scale, anchovies are increasingly making a home for themselves in the North Sea off Germany. The species is usually found in more southerly climes, but the warming temperatures are attracting them to new waters.

The Wadden Sea UNESCO World Heritage Site is also at risk from the predicted sea-level rise. It serves as a resting place for millions of migratory birds traveling between the Arctic and warmer regions to the south. Because it is so rich in food, the birds stop there for several weeks at a time to build up fat and energy reserves for their onward journeys.

While few plant species can survive the salty waters that regularly flood the marshes between the Wadden Sea and the dikes, the environment is alive with tiny insect species and birds that nest at ground level.

If the sea level were to rise too quickly, the Wadden Sea's characteristic mud flats would no longer be exposed at low tide. That would have huge implications, not only for the birds that rely on the ecosystem for food, but for the ecosystem itself.