How the Bosco Verticale - a ‘vertical forest’ under construction in Milan - will look once all the vegetation has been installed.
Greening up our urban environments is vital if we are to cope with impending changes, says Tom Armour, director for global landscape architecture at Arup
By 2050, it is predicted that the global human population will have reached nine billion, with three quarters of us living in cities. This population growth, combined with climate change, resource depletion and pollution is putting increasing pressure on our existing urban environments; recent urban flooding in cities across the world is just one example. If tomorrow’s cities are going to support this tremendous population growth and overcome these challenges, they have to change.
Sustainable urban development is the answer, but it cannot be achieved without recognising the vital role of the natural environment and its fundamental impact on economic prosperity, health and wellbeing. It can no longer come as an afterthought, and as space in cities becomes more precious, planning for greenery needs to be a fundamental consideration, not an optional add-on or a nod towards biodiversity.
In light of this, a new report by Arup, supported by the Landscape Institute and Royal Botanical Gardens, Kew, reveals how we need to rethink our urban environments. ‘Cities Alive’ looks to build nature into our urban systems at all scales via new development or retrofitting.
Green urban infrastructure
Delving deeper, as we are faced with pressure for space within our cities, existing infrastructure needs to be mined for opportunities to integrate nature into our environment. 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.[1]
Increasing the number of trees and woodland within our cities can also bring health and wellbeing benefits such as reducing pollutants from the air and related hospital visits. They can also provide shade and reduce city temperatures and even increase public safety through traffic calming measures; tall or closely spaced trees give the perception of making streets feel narrower, thus slowing drivers down.
Natural flood protection
Increasing tree cover within urban areas can also reduce flood risk, with one study estimating that for every 5 per cent increase in tree cover area, run-off is reduced by 2 per cent[2]. Alongside this, we will need to see our cities shifting from man-made structures such as impermeable concrete, tarmac or roofed to more natural solutions to protect our cities from flooding, including more permeable surfaces such as reed beds and other wetland habitats.
Permeable paving and soft landscape areas will help convert grey to green in future city environments. This is a simple technology, but a vital one to improve water absorption and slow rainwater run-off. This will help cities cope with extreme weather events and increased precipitation whilst significantly visually improving the environment.
The city of Madrid has buried sections of its ring road, replacing the motorway with a 10km-long riverside park
An increasing urban population will also mean greater demands on resources, including energy and food. In a bid to reduce the carbon footprint of cities and our reliance on exhaustible supplies, lighting used within cities will become highly sustainable and integrated into nature. Innovations such as sprayable light absorbent particles could be applied in public spaces including roads, buildings and pathways, bringing additional light and safety to parks and alleyways. Even our trees could produce light at some point in the future, with bioluminescence being spliced into their trunks and branches, significantly lowering the environmental impact of street lighting.
In terms of food production, our report also predicts that we will need to branch out from traditional farming methods, with purpose-built vertical farms soon becoming a regular feature in cities. These urban farms will also play a role in reconnecting city dwellers with nature, teaching citizens about home-grown food and offering a glimpse of a more secure and sustainable food supply. In time, we may even turn to the wild urban environment to meet growing food demands, with citizens foraging within the city for fruits, edible greenery and even insects. This could also lead to parkland being used for activities such as urban farming.
Delivering cities like this will require an integrated approach to urban design, where landscape architects work in close collaboration with government, authorities, developers and associated city design consultants to achieve these 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 our urban environments, we see the potential to create healthier, more resilient and inclusive cities.
[1] Desk Workers who can see a green environment from their desks experience 23% less time off sick that those with an entirely urban view and report greater job satisfaction. Wolf, KI, Human Dimensions of The Urban Forest , Urban Nature Benefits, Psycho –Social Dimensions Of People And Plants (1998)
[2] Coder, RD. 1996. Identified benefits of community trees and forests
