University of Cardiff (United Kingdom) discovered that roof gardening, the creation of living walls, parks and other vegetation spaces in cities could not significantly mitigate the effects of global warming in the form of heat and flooding waves. This is reported in a press release on phys.org.
To assess the effectiveness of landscaping, scientists used a global climate model and weather information from 175 major cities in the world, collected over 15 years of daily observations, from 2000 to 2015. It turned out that the potential of green urban spaces is very limited by the predominant climate in the city. Flood protection will be the most successful in a dry medium, and the cooling effect – in a more humid climate.
Waves of heat often arise in urban quarters due to the effect of heat islands, the cause of which is the predominance of concrete and steel, as well as the absence of water evaporation from plants. Floods occur due to the fact that urban structures adversely affect the natural flow of rainwater. The results were demonstrated that in most cities in the world, landscaping could not fight both problems at the same time.
In addition, precipitation growth due to climate change can reduce the effectiveness of green roofs and walls compared to large territories with thicance soil and root system. Thus, urban planners will need to take into account these features for the design of the cities of the future, in which the consequences of global warming will be mitigated.