Expert Voices: Tom Armour, Director for Global Landscape Architecture, Arup, makes “green predictions” for our growing cities

As cities are set to support the vast majority of people we need them to thrive and be healthy and attractive places for people to live, work and visit. Sustainable urban development is the answer. Despite space in our cities coming at an increasing premium, planning for green can no longer come as an afterthought; it needs to be a fundamental aspect of every city in the world.

In light of this, my colleagues at Arup and I have worked on a new report, supported by the Landscape Institute and Royal Botanical Gardens, Kew, London, to demonstrate how we can rethink our urban environments. ‘Cities Alive’ supposes a future in which the natural environment is placed at heart of urban design. Besides creating healthier, safer and more prosperous environments, this prioritisation of green infrastructure has the potential to increase energy efficiency in cities and reduce our reliance on fossil fuels; both crucial measures for driving the C40 agenda.

Integrating green infrastructure

Crucially, moving to greener infrastructure does not necessarily mean building from scratch. Instead we need to look to existing infrastructure to provide often the most economic solutions.

Increasingly sophisticated technology will allow roofs, walls, building elevations, balconies and façades to be adapted into green spaces, which in turn will advance the health of residents. These walls can act as a filter for pollution when the fine particles are trapped on the surface of leaves, for example.

Urban tree cover is well known to have massive benefits for the climate and our social cohesion, health and wellbeing - absorbing carbon dioxide and acting as a natural cooler and insulator. Even modest tree cover has the potential to drastically reduce the urban heat island effect of cities through evapotranspiration and shading. Placed directly in front of south-facing walls, trees can significantly cool a building and reducing its dependence on air conditioning and cooling systems.

New materials such as ‘green concrete’, which can absorb carbon from the atmosphere and store thermal energy, are also currently being researched. Since a portion of the city will always be composed of concrete, enabling it as a source of resource efficiency will have significant impacts on the urban environment.

Sustainable city fuel

City lighting could also become highly sustainable. Innovations such as sprayable light absorbent particles could be applied in public spaces including roads, buildings and pathways, reducing the pressure on electrical supplies. Even our trees could produce light, with bioluminescence being spliced into their trunks and branches.

Delivering cities like this will require an integrated approach to the design of urban environments, where landscape architects collaborate closely with government, authorities, developers and associated consultants to achieve desired outcomes. To realise this vision, green infrastructure has to take a more central role in the planning and design of cities. By recognising that green infrastructure can be economically integrated and retrofitted into the city, we see the potential to create healthier, more resilient cities whilst significantly reducing their carbon footprint.

To read the ‘Cities Alive’ report, click here