More cycling and walking infrastructure. More greenery. Less cars. Commitment to sourcing renewable energy. There is a plethora of activities a city can undertake to create a green haven, increasing public health and quality of life. Deeply Good takes a look at some of the cities and some of the good ideas that can turn a city from being polluted to being green.
The featured image of this article depicts the inside of the Cloud Forest, part of Singapore’s 250 acre nature park, Gardens By The Bay, created in 2012. The park aims at enhancing the quality of life within the city by increasing the amount of flora and fauna. It is a resounding success. Awe-inspiringly beautiful and ecologically marvellous, Gardens By The Bay represents just one way in which a city can increase their green footprint.
In Paris, the local government recently passed a law which allows citizens to plant their very own urban gardens in public spaces. Permits allow them to grow anything from plant-filled walls, to trees, to planters along the roads. Also, the city will provide the topsoil and seeds upon any request, though plots are required to be maintained by those who proposed them.
In Shenzhen, China, a crowded city of 12 million that is vulnerable to flooding, has begun a project of turning it’s rooftops into gardens. The gardens themselves can help to retain 65% of rainwater and reduce pollution through carbon dioxide intake. The project is part of China’s sponge cities initiative, which is helping poorer communities become more resilient to extreme weather.
Ideas for greenery can come in even quirkier forms. For example, the Dutch designer/artist Daan Roosegaarde has come up with an idea which could revolutionise not only the way our cities look and how we keep them green, but how we keep them lit at night. Through biomimicry-inspired technology, Daan has come up with the idea for a ‘bioluminescent plant’, through splicing the DNA from luminescent bacteria with the chloroplast genome of plants to create a jellyfish-type glow. Roosegaarde hopes that one day it could replace our conventional street lighting, allowing us to plant more trees and save on the electricity bill.
And who said a garden had to be on a horizontal surface? Wall gardens have become more prevalent and more important in the fight to keep our cities green. Drawing on the advances in hydroponic growing, the free space on a number of buildings can now be taken up by plantlife. In London, the Edgware Road Tube Station, among other locations, has a vertical garden incorporated into its structure, created by UK-based firm Biotecture.
Adding greenery to cities improves air quality, the mood of passersby, and can also create more resilience to hotter summer temperature. It stimulates evapotranspiration, in which evaporating water from plants leaves reduces the surrounding air temperature.
TIME FOR REFLECTION
We’ve been experiencing hotter and hotter consecutive summers within the last decade, with heatwaves lasting weeks. Cities are particularly susceptible to these, as pollution and the trapping effect of architecture can create heat pools that keep temperatures up.
We all know that the best reflective colour is white. As the Sun beats down upon our planet, the white snowy areas do their part to reflect that light and heat back out into space, but as those white areas are melting under the strain of climate breakdown, we need to take matters into our own hands. If cities are to be made to be more eco-friendly, and cooler in the long run, the materials used to build with must be changed.
Urban areas are filled with, almost-oppressively, with dark materials – your concrete, asphalt, brick, metal painted black. These dark colours absorb heat from the Sun, growing hotter and hotter throughout the day. In Australia, conventional paving can reach temperatures of up to 67C and conventional roofs up to 50-90C on a hot day. This heat is then leached back in to the streets during the night, not allowing for any respite from it during summer months.
Research done by the Lawrence Berkeley National Laboratory has shown that living on the top floor of a building with a dark roof poses a health risk, after having identifying a risk factor of mortality in the 1995 heatwave in Chicago. The best way to avoid this is to use cool-coloured coatings.
White-coloured coatings or materials applied, not only to roofs, but to walls and even roads, can reflect more solar energy away from a building. In New York, the Cool Roofs Initiative, has seen more than 500,000m² of roof space covered in white reflective coating, reducing the amount of CO2 produced by 2,282 tonnes per year. Research done by NASA suggested that a white roof could be anywhere up to 23C cooler than a normal black roof on the hottest day of the year.
In Los Angeles, a city known as an urban heat island, the local government has begun to paint roads in white coloured sealant that has a high reflective value. This could, as suggestions proclaim, reduce temperatures in the road by 10-15ºF.
As our cities and populations grow, we need to adapt our technologies so that they fit both our current and our future needs. The picture above is the definition of this. These impressive structures make up the Supertree Grove at the previously mentioned Gardens By The Bay in Singapore.
The 18 Supertrees stretch up to 50 metres high, their steel frames housing a whopping 162,900 plants of over 200 species. It is fairly evident that a large part of their function is to serve an aesthetic function, one which they carry out with rare beauty and grace for pieces of architecture, but they also serve environmental purposes. Each Supertree is equipped to harvest rainwater, and some are replete with photovoltaic cells, which mimic the chlorophyll of real trees and capture solar energy. Others are integrated with the conservatories that make up Gardens By The Bay, and serve as air exhaust receptacles, ventilating them.
In London, they have taken interactive technologies to a much ‘lower’ level. In West Ham there is an elevated pedestrian walkway close to the underground, and built into this walkway is an intentional underfoot ‘springiness’. This springiness can be attributed to the five millimetre thick smart tiles that capture the kinetic energy produced by a pedestrian’s footfall, powering the streetlights above, an innovation which was created by Pavegen, and has also been installed in London’s Heathrow.
Another Good Idea in turning cities ‘green’ is something that has been capturing the attention of many people – solar roads. In the Netherlands, a solar energy-harvesting bike path made waves when it produced 3,000kWh – enough to power a small household for a year. Public interest has also been focused on the US company, Solar Roadways, which aims at covering every highway in the US with thick, durable LED-lit solar panels.
It has been theorised that if their plan were to succeed, the solar roadway network would produce more electricity than America uses. The residual heat stored in them melts ice and snow, they are able to store underground cables, and are effectively resistant to potholing. What this could mean for cities would be a vast network of solar roads which powered the adjacent buildings and public transport links.
The World Health Organisation estimates that around 7 million premature deaths are caused by air pollution. This pollution can be found at it’s worst in cities, where high buildings and high vehicle generates and traps a lot of polluted air. In England, around 40,000 premature deaths and even more health conditions are linked to poor air quality. So what can we do about it?
Initially, we can petition local governments to invest in the infrastructure of public transport, making it more reliable. If we can rely on public transport, more people will readily use it than resorting to taking their cars. In Helsinki, there are plans to offer ‘mobility on demand’ by the year 2025. The plans are based around integrating all public transport services; buses, taxis, bikes, and ferries, into one smartphone app. This app would act as both route planner and payment platform, allowing residents and tourist the ease of cheap and convenient travel options.
Some cities around the world are taking other action, banning cars in certain areas or on certain days. Paris bans cars in historic central districts at weekends and during major events where pollution will be high, makes public transport free. Similarly, in Madrid there is a new incentive to encourage the use of public transport. When air quality levels are breached, 50% of cars will be banned, and public transport will be made free.
In Copenhagen, the bike is prioritised over the car, and is widely known as the city with more bicycles than it has people, having 26 ‘cycling superhighways’ . Large parts of the capital have been closed for decades, and the city is currently planning to become carbon neutral by 2025. The car-free movement can be seen in a large amount of cities around the globe, such as Helsinki, Olso, Zurich, Bangalore, and Delhi.
A GREEN CITY
There are effectively an impressive amount of ideas that a city can undertake to make itself more environmentally friendly, but one we have not yet mentioned is very important – it is the ability to invest in renewable energy. A sustainable eco-friendly energy source, if invested in properly, could provide jobs and energy indefinitely. All these technologies and ideas, if integrated properly, could turn a humble city into a bastion of green energy and policy, leading the way for other cities to join in preparation for the future.