Revitalizing the city: urban jungle against heat – real estate – economy

If the occasion were not so disturbing, one might speak of the perfect moment. While the heat and drought once again inspire public opinion and politicians to act, a new volume by Bernd W. Krupka was published in mid-July, which, apart from greening roofs and facades, is primarily devoted to the further development of urban vegetation technology.

arcades and wall decorations

Finally, cities need to be better protected against high temperatures and driving rain. Almost two decades after the first spells of heat and heavy rain, the time has come. Also in Germany. However, mere considerations such as the Federal Environment Agency will not get the job done. “We need to rebuild our cities in order to live with climate change,” President Dirk Messner told the German news agency. “It is primarily a lot more green in cities. Significantly cools. ” Krupka wrote down what it could look like. He agrees with Messenger that areas such as parking lots, streets and paved squares in large cities should be unsealed. In addition, the green roof expert has arcades as green tunnels in urban spaces, green wall systems, extensive green roofs, vegetation mats for adjacent traffic areas such as communication islands and lanes. To name just a few examples. It would be a great job for a functioning park department.

Where there is water and greenery, it is cooler

“With the federal program for adapting urban areas to climate change, we are supporting cities and communities in the preservation and development of green and open spaces,” said Federal Minister for Housing and Urban Development Klara Geywitz in Potsdam on July 19. “Where there is green and water, the environment is cooler.” The federal government wants to take over up to 85 percent. eligible costs.

The author did not care about the costs of his urban ecological application examples – and does not have to: With the dramatic changes taking place around us on land, in water and in the air, money is (almost) insignificant more.

In large cities there is a lack of evaporative cooling of unsealed surfaces

On July 21, Leif Miller, national director of the Nature Conservation Union (Nabu), criticized the fact that there is still no real reversal in land use. “The federal government is far from achieving its goal of a maximum of 30 hectares of daily land use by 2030.” Miller said. For example, rows of huge logistics properties will be placed in the landscape. Sealing would destroy habitats, affect the balance of groundwater and cause more CO2 emissions as new settlements and traffic areas cause more traffic. In cities, neighborhoods overheat because there is no evaporative cooling of unsealed surfaces. According to the Federal Environment Agency around 45 percent of housing and communication areas in Germany are closed. They are built, concreted, asphalted, hardened or sealed hermetically and watertight with foil.

Green roofs and walls have a cooling effect on the city’s climate.Photo: BHW Bausparkasse

The aim of the book is to help plan and implement the revitalization of densely populated urban areas and adaptation to climate change. The basic idea of ​​Krupka: to design urban nature as an evidently efficient urban ecosystem for the future. “This ecosystem consists of a network of vital urban spaces,” suggests the expert: “The basic components of soil, water and vegetation are designed to achieve sustainable, climate-effective and health-promoting effects.” The apparent consequences of climate change in changing the seasons have a greater impact on extreme roof plantings than on ground greening. ‘ Unfortunately, not in a positive way. On hot summer days, the green on the roof has a cooling effect like natural air conditioning. “Black bitumen cardboard and gravel roofs can heat up to 80 degrees Celsius when it’s hot,” says Krzysztof Pomp, an expert at BHW-Bausparkasse, “on the other hand, with planted roofs, the maximum temperatures are only around 20 to 25 degrees”.

Berlin could create new climatic oases in the neighborhoods

With the development of new neighborhoods in mind, which other city would be better than Berlin to take account of the climate change that is now undisputed when drawing up city development plans? Unfortunately, in 2011, no specific urban environmental measures against the effects of climate change were entered into the “Act on climate protection in the development of cities and communes”. There is an urgent need to make up for this neglect with this volume in order to reach areas of urban regeneration that improve living conditions in a comprehensive sense. “We have to go green in cities Create climate oases, ”Gerd Landsberg, General Director of the German Association of Towns and Municipalities, told Handelsblatt. Kupka’s practical recommendations for a “green block” operation for different types of greening would be a good starting point.

According to a survey by BHW Bausparkasse, 64 percent of homeowners want more greenery in their neighborhood. Many still underestimate the enormous positive impact of green roofs and facades on the climate. Greening can lower the temperature around the house by up to five degrees and have a cooling effect, in particular on the urban climate. However, according to the BHW survey, very few respondents (9%) know about it.

Book reference: Bernd W. Krupka: New Urban Ecology in Climate Change. Development of a green urban environment for the future. Ulmer Verlag 2022, 240 pages, 134 color photos, 44 euros.

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