Celle loses green crown: heat check sets city to yellow!

Celle loses green crown: heat check sets city to yellow!

What's going on in German cities? A current heat check reveals worrying results. Celle in particular has given up the green crown as the greenest city in Lower Saxony this year and is now in eighth place in the new Heat Check 2.0 from German Environmental Aid (DUH). Last summer 2024, Celle was still the city in the state best equipped to withstand the heat, which meant it came in 22nd place nationwide. This turnaround is alarming, but it shows how much urban conditions are influenced by dense paving and little greenery.

The DUH evaluates a total of 190 cities with over 50,000 inhabitants in its heat check and introduces the innovative heat impact index (HBI). This index records how many people live in particularly polluted areas, where high temperatures, dense development and a lack of green space come together. Celle has an HBI of 14.57 and is therefore in the average area of ​​concern within Lower Saxony.

Detailed assessment of cities

The situation is particularly precarious for the over 12 million people in German cities who are exposed to extreme heat stress. The analysis includes cities affected by heavy imperviousness and a lack of greenery. In comparison, the greenest city in Lower Saxony, Lingen (Ems), has an HBI of 12.77 and therefore enjoys a better ranking. Other cities in the yellow traffic light field such as Wilhelmshaven (13.05), Nordhorn (13.45) and Oldenburg (13.54) also performed better according to the DUH results.

At a national level, the results show that some cities are particularly badly affected. Mannheim is the worst-rated city, followed by Ludwigshafen am Rhein and Worms. These are all cities where between 88 to 91 percent of the population lives in highly polluted areas. These poor values ​​result from the dense development and lack of vegetation, which further increases the heat in urban areas reports Spectrum.

The problem of sealing

In Celle, the surface sealing rate is an impressive 44.59 percent, which doesn't make the situation any better. With a green volume of just 4.17 cubic meters of vegetation per square meter, the city does not meet the requirements of a healthy urban climate. Trees and parks lower the ambient temperature through evaporation and shade, but in many cities like Celle this is hardly present. For these reasons, the DUH has evaluated a major challenge for urban planning and emphasized the importance of green spaces. Concrete surfaces often store heat and release it into the environment for hours, while water surfaces, trees and green facades could effectively improve the city climate.

Overall, the DUH's Heat Check 2.0 clearly shows how important valuable urban planning with sufficient green spaces is. This is the only way to effectively counteract the phenomenon of urban heat. It remains to be seen what measures cities will take to address this challenge. The need to promote urban greenery is clear - this requires innovative approaches and a good hand in urban design.