Info-Service Editorial, October 2018, by Simon Tschannett and Matthias Ratheiser
In August 2018 we attended the International Conference on Urban Climate (ICUC) in New York City; there were well over 600 delegates from approximately sixty countries. The numerous lectures confirmed that there is no single standard procedure for adaptation to climate change. To the contrary: new studies clearly show that for each city and urban district a specific mix of measures must be selected – and this mix depends on many factors such as sealing, building height, traffic, wind or fresh air corridors.
We also noted that more and closer attention is being given to the measures taken and their impact on urban populations.
For example, flowing and standing waters are no useful means for cooling the urban surroundings. They can only take effect when water is sprayed (e.g. by water fountains) or if combined with dense tree vegetation. Yet trees have an unconditionally positive impact on quality of life only under certain conditions: although they provide shade and lower daily peak air temperature through evaporation, they may also reduce nocturnal cooling and retain pollutants at pedestrian level. And keeping this in mind, it is therefore important to place restrictions on gasoline- and diesel-fuelled vehicles in wooded areas.
Greened facades up to a height of six metres also have a positive effect on pedestrian comfort. For trees and plants on building facades the water demand should ideally be met in a climate-neutral manner. Trees and green facades show the best effect when combined interactively, i.e. not standing separately. The cooling effect of parks extends only for one or two blocks. Temperature in areas between parks should be reduced by introducing further trees and plants.
In conclusion, it can be stated that human beings will be able to feel comfortable in cities despite climate change – if the measures taken are suitable for the sites in question.