So the question is: Does one of the two calculation methods make more sense, and is the other parameter really “wrong”, as CSU politician Hans Hammer claims?
The Department of Climate and Environmental Protection of the City of Munich (RKU) also examines surface sealing in the state capital every four years. Spokesman Gesine Beste explains:
RKU’s sealing map monitors the degree of sealing in relation to the area, as this is more meaningful for many questions.
Figures can lead to incorrect conclusions
According to Gesine Beste, if you want to look at the development in relation to sustainability and climate protection, the per capita indicator can even distort the picture: If you only look at the per capita indicator, it will e.g. mean that with an increasing population and the same sealed area, theoretically the seal decreases. “This figure thus leads to erroneous conclusions regarding the effects of sealing on the urban climate, biodiversity, soil and water protection and thus sustainable development as a whole.”
According to Gesine Beste, the number per. per capita be useful for some purposes – the validity of the information must be checked in each case.
The RKU spokeswoman continues: “In terms of urban locations, it is correct that Munich is in a bad position due to the small area. If, for example, Perlacher Forst were part of Munich, it would have an impact on the overall degree of sealing. ” On the other hand, the presence of a single large green area on the outskirts has no impact on the built environment of the population in most parts of the city.
According to Best, it is a fact that Munich, with the exception of the English Garden, has no extensive green areas. It is therefore urgent with area protection all the more so. Her department is therefore in favor of a differentiated consideration of the proportion of sealed surfaces in relation to the total area and speaks against a simplification or comparison of cities based on a single indicator, which can not do justice to the complexity of the subject.
According to experts, comparative considerations are often ineffective
Michael Thiel from the Department of Geography and Geology at the University of Würzburg, who was involved in the LfU study, is also against the fixation on urban locations. Even though there is a uniform data base based on satellite data: Each region and each city has its own characteristics, before which one has to look at the corresponding key figures. Factors such as the economic conditions or the situation in the rental market should also be taken into account in this consideration.
According to Michael Thiel, it is not bad in itself to state the sealed area per. inhabitant. This parameter can be used to show how effective sealing can be in cities like Munich – the same amount of sealed area holds many more people here than in rural areas. “But it makes absolutely no sense to use other indicators to achieve a better ranking,” says the researcher. Everyone should understand that sealing is a general problem and that surface sealing is already quite high.
Asked by #Faktenfuchs, the Federal Statistical Office and the Bavarian State Office for the Environment (LfU) also stated that both indicators were justified when considering surface sealing. But the number per. per capita would better serve to comment on how effectively the already sealed area is being used.
CSU and Free Voters defend their actions
The faction of the CSU and the Free Voters in Munich’s city council is behind the process that city councilor Hans Hammer has initiated following questions from #Faktenfuchs. The purpose of the inquiry to the planning department was to obtain as complete a data basis as possible for decisions in the city council. For this reason, among other things, it was asked to determine the dense area per. inhabitant.
Political decisions in Munich are made on the basis of the prevailing conditions there – but the subject of surface sealing in comparison with other cities is also repeatedly discussed in the debates. “If you then say that Munich is a leader in terms of surface sealing, but from the point of view of the city’s department for urban planning and building regulations, it is not true at all, it should also be named accordingly.” writes the parliamentary group to #Faktenfuchs.
The Planning Department adhered to the question for its initial assessment despite the opposite assessments of other subject departments. In it, the CSU and Freie Wahler agreed that “this direct comparison with other cities based on the pure municipal area does not make sense”. It goes on to say: “To compensate for the differences that exist only due to the delimitation of administrative boundaries, the amount of sealed area per capita in the respective municipality is much more meaningful to show area sealed.”
The city council faction of the CSU and the Free Voters in Munich will avoid the city ranking as the most sealed in a nationwide comparison. In a press release, she states that the degree of sealing in the city of Munich has so far been incorrectly measured – Munich performs significantly better than other cities in comparison. However, the parliamentary group does not draw its statement from new data – instead, it provides another indicator: Instead of the proportion of sealed area, they rank the cities by sealed square meters per square meter.
The planning department in the city of Munich, which compiled data for the CSU and the free voters, writes that a comparison based on this indicator is more meaningful.
However, other specialist bodies and experts advise against this approach: the per capita indicator leads to incorrect conclusions, especially when it comes to the development of sealing. The population is a good way to show how effectively the already sealed area is being used – but it does not make sense to look at it alone.
According to the experts with whom #Faktenfuchs has spoken, a comparison between different cities is generally recommended only to a limited extent, because each region and each city has different conditions to which the indicators must be seen.