Climate change prompts Berlin to become a ‘sponge city’

With climate change comes an increase in floods and extreme heatwaves in urban areas. Berlin, Germany, sought out a nature-inspired adaptation method, with measures to increase the city’s ability to act as a sponge—absorbing rainwater and cooling itself.

In August, the senate of Berlin released “StEP Klima KONKRET”, which details a plan for city climate action. The abstract states: “The goal is adaptation in the form of no-regret measures that would make social, economic, and ecological sense even without climate change.” Thus, nature-based solutions are ideal in such a context.

In a natural ecosystem, rainwater is soaked up by the soil and plant life. Then, most of the water evaporates and the rest travels further into the ground. The rainwater cools the surrounding environment as it evaporates.

Cities on the other hand are made of concrete, glass, and steel, which draw in heat and repel water. Furthermore, as streets cannot absorb water, it’s flushed away into sewers and is hindered from its natural evaporation and cooling processes.

That’s where the concept of a ‘sponge city’ comes in, which seeks to preserve the benefits of this natural system by keeping the rain where it lands.

What infrastructure is needed to achieve this?

Namely, green roofs and walls, and urban wetlands. Furthermore, roadside trenches can build runoffs which retain rainwater.

Learn more via this video on Bloomberg News.