Cities are now home to more than 50% of the world’s population. And that number is expected to rise to 70% by 2050, bringing 3 billion more people to our cities.
Altogether, cities account for more than 70% of carbon emissions and thus have a major role to play in both tackling and adapting to climate change.
As we have seen in this previous article, in the past few decades, cities have mainly responded to a rising population with urban sprawl. We now know how damaging sprawling can be for the environment and for human health, and we know it has to stop if we want to be able to reduce our environmental impact while welcoming more and more people in urban areas.
So let’s see what are our alternatives to urban sprawl and how to build greener cities.
We will explore a few possibilities/principles that could be or are already implemented as an alternative to urban sprawl.
#1. Compact neighborhoods
Sprawl is a relatively new urban concept which appeared with cheap fossil fuels and the rise of private automobiles. Before that, cities were built for pedestrians, bicycles or horse rides at most.
Without giving up on modern technologies, cities must be thought of and designed for pedestrians and bicycles again.
Improving walkability and cyclability in cities is a powerful way to reduce emissions, while improving the quality of life and health for residents.
Some cities are already implementing this concept, with the 10min walk city plan of Seoul or the 15min walk city plan of Paris, where the idea is to create neighborhoods where every essential residents’ needs are easily within reach in 10 or 15 minutes by bike or walking.
To enforce more compact and walkable neighborhoods, urban planners and decision makers need to implement minimum required densities, increase the densities of certain urban areas and completely restrict the use of further natural or unused land.
2. Adequate public services and transportation
In order to implement denser neighborhoods and stop the reliance on cars, cities must provide efficient and varied transportation choices.
If neighborhoods need to be denser and more walkable, different districts composing the urban landscapes and cities need to be well interconnected with efficient public transportation. To avoid the use of cars, cities need to develop, improve and offer more public transportation between dense areas.
Technology can also be of great help when it comes to transportation, with self-driving vehicles and car sharing boosting efficiency by maximizing use of vehicles and reducing need for space to park idle ones.
Compact neighborhoods also need more and closer public services. While in the past decades, the trend has been to concentrate services in massive infrastructures, thus creating huge hospitals or schools in a single location in a city, we need to revert that trend and multiply smaller structures spread out through the urban landscape. This will allow public services to be within walking distance from everyone, and will also provide jobs closer to residential areas, thus reducing the need for transport.
#3. Energy efficiency and resiliency
Nowadays, our cities are entirely dependent on fossil fuels. We need to develop sustainable energy as much as possible, not only for having a cleaner and more sustainable way to create energy, but also to improve cities' resilience. We now see with some extreme weather events or the example of the Ukrainian war that power, when produced in one specific area, can easily be cut off. Producing sustainable and local energy allows for a better resiliency when crises happen.
One of the best ways to be sustainable is also by using less energy, so that most of our new buildings should be having the lowest impact, from design to operation and dismantling. Green or passive buildings should be the rule in our cities by now and retrofitting the existing buildings needs to be a priority for our cities.
Cities are a good scale when it comes to energy efficiency, with co-generation facilities taking waste heat from electricity generation and using it to heat or cool buildings. For even more benefit, the carbon dioxide generated in the process can be captured and used for local industry. Buildings can also transfer heat, cold or energy at different times of the day depending on their usage. (ie. a residential building producing electricity can be cool during the day and transfer the energy produced to office buildings and vice versa overnight).
#4. Green spaces, preservation and urban farming
Sprawling often leads to wide streets made for cars, with a few trees on the side, and all the greenery being private lawn gardens.
Compact neighborhoods, while being a more sustainable alternative to sprawling, also leave more space for green areas, which need to be thought of from the design phase and incorporated everywhere in the city or district; through parks, community gardens, rooftops gardens, urban farms, green facades, green patches along sidewalks, etc.
Compact districts also allow cities to leave some natural open-spaces totally wild and free, for wildlife to thrive next to human settlements.
The point of this greenery is to help tackle and adapt to the effect of climate change. By procuring close sources of food with urban farms, cooling the urban areas with more trees, leaving more space for biodiversity or bringing communal areas for people to gather and meet.
#5. Socio-economic viability, high quality of life and equality
To be successful, a city or district must have enough room for everyone to live and have leisure time. It should also provide enough jobs to everyone living in it.
Compact neighborhoods should be designed for mixed use, where residential areas or buildings are mixed with retail, small industry, workshops, public services jobs, urban farming jobs, etc.
There must be a job to meet the housing balance requirement from the design phase to the operation and the life of the neighborhood.
Designers should also make sure to provide various housing types and prices, or activities and services.
An idea to switch from our low density neighborhoods to denser ones is to transfer the building rights from some areas to others, in order to prevent certain areas from being too built up, while also creating an economy out of transfer rights.
Cities, with their population concentration and their carbon footprints, must reduce their environmental impact. In the meantime, they will need to adapt to future conditions and be more resilient and independent to sustain a good quality of life for their dwellers.
The good news is, as confirmed by the latest IPCC report, that we now have all the necessary technologies and financial resources to both adapt to and mitigate climate change.
We now need to act, cities need to act.