Circular Cities: A Key to a Truly Sustainable Urban India

In a time of smart cities and rapid urbanisation, we need to look at what our cities thrive on. Material resources, food, and water are essential to run a city - but do we have enough to sustain growth? This article looks at circular cities, a self-sustaining model and its application to India.

Sharon Sabu
Min Read

If you are reading this, there is a high probability that you are living in an urban region. Or at least you will be, in about thirty years from now. Our cities are growing at an unprecedented rate, with 68% of the world’s population expected to live in urban areas by 2050 [1]. India alone is expected to add nearly 416 million urban dwellers and be home to the world’s most populated cities by 2028, with Delhi topping the list [2]. However, what do these numbers mean for us?

Cities are engines for economic and industrial growth; as they expand, so will their consumption of resources increase. Even though they occupy less than 2% of the Earth’s surface, cities currently consume 75% of natural resources and produce 50% of global waste [3]. Unfortunately, the linear production models prevalent across the globe, in which over 90% of the raw materials used in production are not cycled back into the economy, are leading to increased waste generation and carbon emissions [3]. This is true especially in India, which is home to 22 of the 30 most polluted cities globally, with their levels of per capita waste generation rivalling those of whole countries [4]. Most of this waste is discarded at landfills or unmanaged dumpsites, causing far-reaching environmental and health hazards.  

To solve this crisis and create livable and sustainable environments in the process, our cities need to fundamentally rethink their models of consumption and production, moving away from a “take-make-dispose” economic model to a “make-(re)use-recycle” model — in other terms, a circular model. But what does a circular city actually look like?

What is a Circular City?

A circular city is one that recycles, repairs, and reuses products and resources rather than throwing them away. Here, waste from one process becomes an input into other processes, effectively eliminating waste as an end-product.

Circularity has immense potential to respond to today’s sustainability challenges, reducing the use of raw materials and keeping extracted materials in the loop for as long as feasible. This drastically minimises the ecological footprint of human-made products, as a fully circular economy can cut down resource use by 28% and carbon emissions by 72% [3]. Integrating circular principles into cities can have immense positive benefits, as circular cities can drive demand for greater sustainability in the public and private sectors and positively influence future development. The Ellen MacArthur Foundation envisions a circular city through the following facets [5]:

Planning in cities

  • Greater proximity between where people live, work and play.
  • Mobility shifts to zero-emission vehicles shared transit and walking and cycling. This reduces pollution and congestion and boosts residents’ health and interactions with local businesses.
  • Instead of throwing materials ‘away’ to landfill or incineration, a new distributed system of resource management, nutrient flows, and reverse logistics makes the return, sorting, and reuse of products possible. Materials stay in use.

Designing in cities

  • Infrastructure, vehicles, buildings, and products are designed to be a combination of durable, adaptable, modular, and easy to maintain and repurpose.
  • Materials are non-harmful, locally sourced, and from renewable feedstocks where appropriate.
  • Materials can be composted, recycled, and reused.
  • Renewable energy powers cities.

Making in cities

  • Buildings, vehicles, and products are assembled using techniques that design out waste.
  • Local ingenuity and skill levels increase as the focus is put on decentralised, distributed production within cities.
  • Through digital material banks, the composition of buildings, vehicles, and products is known, enabling their repair and reuse.
  • Products and parts are created on-demand and on-site, transforming construction methods and storage needs.

Operating and maintaining in cities

  • Products are no longer used just once. People repair and refurbish their products at the individual, community, and commercial levels.
  • Vehicles and infrastructure, from roads to street lights, are operated and maintained so that materials, energy, and water are used effectively and can be reused and recycled.
  • Buildings are refurbished, improving how they are used and operated.
  • New career possibilities and jobs emerge.

Managing Malba in Circular Cities

The management of construction and demolition waste (our very own malba!) is an important part of enabling circularity in cities as they are a significant waste stream, accounting for nearly one-third of global waste generation [5]. Adopting a circular approach to construction and manufacturing processes can help eliminate waste generation and reduce resource consumption. Some ways to do this are:

1. Sourcing materials strategically

  • Selecting construction materials that can be sourced locally (including by-products) and kept in use continuously, can reduce virgin material demand.
  • Materials made available during deconstruction can be reused.
  • Selecting renewable materials where appropriate can further reduce dependence on finite resources.
Figure 1: Galaxy School in Rajkot by Surya Kakani Associates was constructed using locally available materials, industrial by-products, and Bhuj earthquake debris for its construction

2. Using resource-efficient construction methods

  • New industrial construction techniques such as prefabrication have several benefits, such as reduced waste generation and increased cost and time-efficiency.  
  • 3D printing of building units, from components to entire buildings, also creates complex forms with minimal resource consumption and waste generation.
Figure 2: Tvasta, an IIT-Madras alumni startup recently constructed India's first 3d printed home

3. Developing ‘Buildings as Material Banks’ (BAMBs)

  • Technology such as building information modelling (BIM) and similar digital building mapping technology can help envision buildings as ‘material banks’ from where materials can be mined.
  • With such building material maps, owners will have information on what materials and components are in the building, where they are sourced from, and guidance on their potential future use.
  • In this method, buildings are designed keeping disassembly in mind, which makes it significantly easier to take them apart and give them a second life.
Figure 3: BRIC or Build Reversible In Conception is a BAMB Project

Would circular cities work in India?

Yes, and there are huge incentives to support this transition!

By adopting circular economy principles, India can earn annual benefits of approximately $624 billion in 2050 – equivalent to 30% of India’s current Gross Domestic Product (GDP) [6]. Circular processes would also decrease greenhouse gas emissions by 44%, improving the quality of life of city dwellers. The rapid urbanisation projected to occur in the next decade in India provides the perfect opportunity for incorporating circular principles in new cities and infrastructure and thus integrating them into the daily lives of new residents.

Moreover, even though the term ‘circular’ may sound foreign to most Indians, the values embodied in circular cities are familiar to us. Think about the journey a discarded t-shirt takes in an Indian household — it would first be used as a duster, then used to mop floors, and then discarded when it is too frayed to use. Most households in suburban and rural regions compost their bio-waste or use it as fodder, and plastics are cleaned and reused several times for myriad purposes until they are discarded. Reusing and recycling come naturally to us — it just takes a systematic, collaborative approach to scale them to a city-level process. But what would that look like in India?

The “Loops as Leverage” project proposal for Coimbatore (Covai), Tamil Nadu, shows us what a circular city could look like in the Indian context. The proposal focuses on four resource loops — people, water, food, and energy — and looks at ways of closing them with the aim of creating adaptive, resilient, and self-sufficient communities [7].  Through a series of guiding actions that close each loop and strategic tools that help carry out these actions, the proposal envisions a circular Coimbatore by reinforcing local infrastructure and building partnerships between local organizations.

While the proposal highlights several useful strategies for incorporating circular processes into cities, it is not a one-size-fits-all solution. Every city has a unique set of resources and faces unique challenges, and their vision for a circular city will have to reflect these strengths and opportunities. The road to a circular city involves technical innovation, redesigned infrastructure, new business models, sustainable and fair procurement models, as well as motivating citizens to adopt sustainable lifestyles. To truly close the loop of circular cities, common collaborative action between different stakeholder groups within cities is essential, involving private initiatives, entrepreneurs, NGOs, policymakers, academia, and people like you and me.

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Edit - Malba Project

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