In 15 years, more than 60 per cent of the global population will live in cities and rapid urban expansion is predicted to continue. In making urban growth more sustainable and inclusive, and cities more climate-resilient, there are many opportunities to be seized.
Cities are key contributors to many environmental problems, such as air and water pollution, and more than 70 per cent of global greenhouse gas emissions can be traced back to cities according to UN HABITAT.
The risk to cities from climate change
At the same time, cities are highly vulnerable to climate change impacts, due to the fact that many urbanised settlements are located in highly exposed coastal areas and riverbanks, prone to sea level rise, storm surges, tropical cyclones, flash floods, and landslides.
Climate change is turning cities into “harsh and sweltering hotspots” as Grist illustrated through its piece on New York. The urban heat island effect is when an urban area is significantly warmer than its surrounding rural areas due to the modification of land surfaces and other human activities. This effect can be particularly harmful during a heat wave, as it deprives urban residents of the cool relief found in rural surroundings during the night.
Thermal discomfort in the Spanish city of Valencia during a summer night based on surface temperature and relative humidity data. The lighter the area, the stronger the discomfort is. The white border is the administrative border of the city (the eastern part of the city is missing because the satellite sensors can detect only a limited area during one overpass). The rectangular marker indicates a large park that is a cold spot inside the city and the triangle indicates the airport that is a hot spot in the rural area. The related study can be found here.
Green is the new black
One of the best ways to mitigate the urban heat island effect is to increase the amount of well-watered vegetation, for example, by building green roofs, creating urban gardens, and planting trees around the city. There are plenty of examples of successful urban community gardens (Budapest, Lisbon, Berlin), green roofs, and even green rooftops on buses.
The Spanish city of Valencia has a particular story on choosing “the green” over “the black”. To avoid flood damage that occurred time to time in Valencia, local authorities decided in the 1960’s to divert the Turia river at the border of the city, and turn the old riverbed into a main traffic axis with multi-lane roads and rails. However, thanks to active citizens, the original plans were never turned into reality: instead of creating an asphalt jungle in the heart of the city, the new public space was transformed into a garden that serves as one of the most popular recreational area till today. “The Turia riverbed is part of my life; I run there almost every day”, one Valencian citizen, Eduardo, says.
Greening public spaces
Greening public spaces is a key element of climate-friendly urban planning. Numerous studies (for example, on the cooling effect of urban greenery, on the benefits of visiting green spaces and on the positive effects of biodiversity) have shown that urban vegetation, in addition to purifying the air and beneficially modifying the urban climate, has a positive psychological impact too. A green living environment reduces stress, increases cognitive abilities, and academic performance. According to the internationally recognised biologist and author, Edward O. Wilson, human beings have an inherent emotional bond with all living organisms, so they seek connections with nature, which he calls biohilia, the “love of life or living systems”.
The Biophilic Cities Project
The Biophilic Cities Project is based on the biophilia concept and was established at the University of Virginia’s School of Architecture. The project aims to foster the cultivation of urban life through documenting best practices in biophilic urban design and facilitating dialogue between researchers, urban planners and policymakers. European cities (Birmingham in the UK and Vitoria Gasteiz in Spain) are also part of the international network of Biophilic Cities. For example, Birmingham, the one-time industrial giant, aims to be the UK’s first “natural capital city”. It has plenty green space with many local nature reserves, like the Moseley Bog (famous from J.R.R. Tolkien spending lots of time there as a child), or the 1 000 hectare Sutton Park (the first urban National Nature Reserve in the UK). In addition, the city revitalizes its canal system that provides pleasant waterfront atmosphere—vital during hot summer days.
Before and after image of a street in Copenhagen (Denmark) from the gallery of urb-i. More images can be found here.
Tackling air pollution from transport
To make our cities more healthy and livable, reducing the emissions of air pollutants is crucial. Transport is alone responsible for one quarter of the EU’s greenhouse gas emissions, to which urban traffic has a major contribution. Reducing car traffic and promoting cycling culture has a well-known tradition in Northern European countries. Tina Saaby, the chief architect of Copenhagen—recognised as “the most livable city”—explained in a lecture how they turned their focus from a car-oriented to a human-oriented city design.
The paradigm shift started in the 70’s when Jan Gehl, a Danish architect, raised the questions: What is the effect of the built environment on people’s activity and behaviour? Does the urban space attract the residents? After studying people’s behaviour on the street of Italian cities and in Copenhagen, he started to better understand the patterns of life which were taking place in public spaces, and began to collaborate closely with the city planners. The core of his concept is that the urban space should function as a forum for social interaction rather than a temporary intermediary space to move from A to B by car.
Through years of meaningful dialogue between architects, the municipality, local businesses and the citizens, more and more pedestrian zones were created in Copenhagen, turning the focus from cars to people. The idea of “making cities for people” has become more and more influential, catalysing projects all over the world to reduce car traffic in cities.
Before and after image of a street in Budapest (Hungary) from the gallery of urb-i. More images can be found here.
The Brazilian urban planning start-up called urb-i came up with a brilliant idea to draw attention to the importance of human-friendly, green urban planning in a simple but spectacular way. Using the time machine feature in Google Street View, they have been mapping thousands of examples of pubic space transformations which prioritize people over cars. More than 3000 photos from over 50 countries show how simple transformations can change the way we see and feel about the public space.
Green design and human-oriented urban planning is essential to ensure the well-being of urban residents in a warmer world. Exciting transformations of the urban space are happening all around the world—how about your place?
Check out the before-after pictures and get inspired!
This article was written by Annamária Lehoczky of the Centre for Climate Change, URV.
“Greening the city” is a panel discussion taking place on 30 October at Climate-KIC’s Climate Innovation Summit in Milan and will explore many of the concepts referenced in this article, such as: nature-based solutions for urban planning, biomimicry and bio-based construction, local materials and vernacular architecture, and connecting urban and rural areas. Register today!