Dipl.-Ing. Nicole Baumüller
Interview of March 26, 2014 with Alina Vandenbergh
Why is it important to consider the effects of climate change in urban planning?
Climate change is proceeding and the consequences like heat waves, floods and torrential rains will increase noticeably. Since a majority of people live in cities and therefore are directly affected by these consequences, cities are particularly required to protect their occupants, buildings, infrastructures and free spaces against possible negative climate effects. And this sooner rather than later since cities cannot be converted within a short period of time. The effects of climate change on cities varies, depending on the cities specific position, climate and structural contexts This needs to be analysed on site, to find suitable adaption strategies. So cities are crucial players in the adaption of climate effects. Here, city development is particularly suitable with its functions and instruments.
Are cities particularly affected by heat stress and if yes, why is that the case?
The increasing heat stress caused by climate change takes effect more intensively in cities. The reason being that cities have their own city climate which is usually warmer, dryer and with lower winds. The densely concentrated buildings and sealing lead to storing of warmth in structural masses. The stored heat is then slowly released during the night. Compensating factors like evaporation active green spaces, that regulate the temperature peaks, are significantly lower. That’s why cities are in particular warm at night and that reduces the sleeping comfort. During the day, temperature differences are less pronounced and it depends on the small scale climate situations, whether a place or city is perceived as pleasant. So shaded parkways, places with waterworks can have a good residential quality, despite the heat. It is important that they are reachable for many.
Can you give examples of cities in Germany which are in particular relevant or less relevant to this topic and explain why that is the case?
Cities like Berlin, Stuttgart, Freiburg, Dresden and cities in the Ruhr district have dealt with the phenomena heat island effect and measures of planning for some time now. One reason being, that summers have already been stressful in the past. The main reason is the local climate situation in which cities are contained - these are often low wind areas. Another disadvantage are basin topographies like in Kassel, Stuttgart and Dresden. So in well aerated coastal cities like Hamburg and cities in higher areas, heat is not so relevant as it does not get so hot and humid. Climate change, with its outlook on drastic intensification of the situation during summer months, is also alarming to other cities. In the past years, a few German federal research projects on the topics of climate adaption and planning (KLIMZUG, KlimaMORO, KlimaExWoST) existed, in which regions and cities were involved. It became clear, that besides floods and torrential rain, heat is a key issue for urban development.
Are there good examples one can look at for the reduction of heat stress in urban planning?
Cities that take this issue seriously, have to concentrate intensively on the affects of city climates and microclimate and possible measurements for the reduction of heat in cities. Additionally, they must target their planning instruments, make measurements binding and legally specified. The state capitol Stuttgart is a model for other cities, since Stuttgart has integrated climate issues into their planning for decades and has its own specialist department. Furthermore, it informs its citizens with a city climate website on the internet. But also Berlin, Freiburg, and cities in the Ruhr area focus on this issue. Due to current diverse federal research projects on climate adaption, more cities like Nürnberg, Karlsruhe, Dresden, Jena, Regensburg, Saarbrücken, Frankfurt and Essen, concentrate intensively on the topic of city climate and heat and therefore serve as role models. It will be interesting to see, how these cities will integrate those define adaption goals and measurements into the planning and what importance climate will have in the consideration of single planning processes in the future.
What impact does climate change and the involved increase of heat stress have on the aging citizens?
According to climate research, heat stress caused by climate change will significantly increase. Heat waves will rife, last longer and will reach higher temperatures - in cities with some days above 40°C. The long lasting heat stress as well as higher temperatures will strain especially sick and older people since their body cannot regulate heat as well. Since our society is getting older and the proportion of the over 65 continuously increases, the issue becomes even more particular. So the health system should work more closely with urban development and promote emphasis on a local political level.
What measures can be taken in cities to reduce heat stress?
There are various strategies to lessen extreme temperature peaks in cities and improve the quality of residential conditions within urban space. During the day, it is essential that as less as possible heat energy is collected by buildings, streets and parking spaces. Streets, backyards, squares as well as parkways could be shaded by trees and draperies and its also the most pleasant in the shade for people during the day. Water elements in public places help to refresh the body. If possible, paved areas should be unsealed and planted, since they can cool the air by evaporating, but it is important that these areas always have enough water. Buildings can be protected by planting on facades and roofs. Alternatively, highly reflective paint could also help reduce heating up. For nightly cooling down, cold air supply through fresh air corridors in strained city districts are very effective.
Can a citizen participate in the planning of climate friendly urban development?
Urban development is a political process. In principle, all citizens have a voice in ongoing planning processes and building projects within the framework of a formal participation procedure. In addition, local politics and city administration are relying more and more on a broad general public dialogue with issue related events. In the case of climate adaption, this is fundamental as this challenge can only be conjointly managed and personal responsibility is required. Some cities have workshops and information events. Citizen’s initiatives are always a useful consolidation for this process. Apart from that, everyone can contribute within their own environment – in living and working spaces, backyards and garden designs- so a city can be more adapted to heat and quality of life in our cities can be preserved.
Nicole Baumüller studied architecture and urban planning at the Stuttgart University and the University of Melbourne, Australia. After her degree, she worked as a urban planner in a freelance planning office for two years and subsequently at the office of urban planning and renewal in Stuttgart. During that time, she worked on several international research programs.
She is a scholarship holder of the State Graduate Sponsor Program under Prof. Dr. Franz Pesch at the Stuttgart University and writes her thesis on: "Climate adjustment as a component of sustainable urban development - Planning adaption strategies for the protection of heat stress in cities".