There is pressure to come up with the best remedy for adaptation and mitigation to climate change, due to the sensitivity of urban ecosystems to heat stress and the predictions for a rise in temperature. Can green façades be an easy-to-implement and sustainable strategy to keep the cities cool? The open access journal One Ecosystem published a new study that utilizes the Bayesian networks to evaluate the applicability of this nature-based remedy, in the context of the urban environment of Berlin.
Bayesian network displays the likelihood of success for façade greening in the status quo in Berlin. (Credit: Sprondel et al.)
Mid-latitude cities are faced with the challenge of urban heat, which is probably heightened by global climate change. To adjust the new buildings and the building stock to severe climatic impacts, façade greening has been recognized as a significant approach, among the methods to adapt the urban environment. However, not much is known on factors that impact implementation probabilities for this adaptation step.
In spite of the development pressure, façade greening could be a suitable means of establishing vegetation in the cities. Façade greening is not used for any other purposes, and does not require a lot of space on the ground like other horizontal green and open spaces in cities. Consequently, it eliminates user competition and pressure.
To deal with the effects of urban heat, many German cities in the past have come up with climate change adaptation strategies with particular emphasis on nature-based approaches for urban planning. Façade greening is specified as a means of improving microclimatic conditions in 15 out of the 24 German adaptation strategies. However, what is the outlook towards this approach and what is the probability of implementing?
A team of scientists analyzed possibilities and attitudes in Berlin, and found that experts estimate the probability of an implementation of façade greening at only 2% under the current circumstances. However, a backyard greening program with a different scenario that involves financial incentives has indicated that the chances can be increased up to 14%. Nevertheless, the “willingness” of the involved parties and the proper combination of legislative and supportive factors was a critical pre-condition for implementing the measure.
"Our analysis allowed for ranking the influence of each of the factors on the outcome the research and we were surprised to see that in this case the "attitude" of determinant actors is of outmost importance, while financial prerequisites, legal and technical conditions also have an influence on the decision to install green façades but remain lower on the list.
Nora Sprondel, lead authot, Technische Universität Berlin