For cities working on impactful sustainability strategies, the right data can assist in critical cost-benefit decision making.
Cities are centers of human activity, vital hubs that drive the global economy. They house the majority of the world’s population, and are growing in both numbers of people, and size. In 2018, the number of cities in the world with at least 1 million inhabitants grew to 548. Amid a global transition towards circularity and sustainability, cities around the world are working to address climate change, focusing on a positive environmental footprint in tandem with socio-economic wellbeing.
Although cities occupy minimal space, their impacts are, by contrast, massive. They provide jobs, access to cultural, educational, and health facilities, and are hubs for communication and transport. Consequently, they have huge energy and consumption demands, generate large quantities of waste, and produce large concentrations of pollution. There’s a lot to take into account on the journey towards an entirely circular city.
Using data to accelerate and scale-up sustainable city solutions
A shift to sustainable cities is already happening, with a range of cities leading the way on different aspects of the transition. According to the Arcadis Sustainable Cities Index, “Sustainable cities can be thought of as places that are planned and managed with consideration for social, economic, environmental impact, providing a resilient habitat for existing populations, without compromising the ability of future generations to experience the same.” When it comes to transitioning each city to a fundamentally sustainable state, data has the potential to provide well-informed decision making, as well as facilitating the acceleration and scaling up of solutions.
By using a data-driven approach, cities can equip themselves with the right tools to plan, develop, and construct a space in which citizens can thrive, while having a positive environmental impact. Tamara Streefland, Consultant and Cities Program Lead at Metabolic, presented at the Prague City Data Congress, talking about the benefits of data tools such as material flow analysis, urban mining, and spatial analysis, and how to scale up solutions.
Data-driven tools for evidence-based interventions
Material Flow Analysis
Material flow analysis allows cities to make smart decisions by clearly understanding where their greatest environmental impacts are taking place. In many ways, cities are like human bodies – they have an ‘urban metabolism’ that stocks up on resources, consumes, and then disposes of what is leftover in the form of waste.
“Material flow analysis provides a solid basis for identifying where we can have the most impact when implementing solutions. It also allows cities to monitor, aiding progression towards long-term goals and building evidence of which solutions are most effective in delivering desired results.” – Tamara Streefland, Metabolic Consultant and Cities Program Lead
A material flow analysis visualizes all these material inflows and outflows, showing, for example, food and energy consumption, emissions, or solid waste streams and how they are connected within the system. By gaining this overview, it’s possible to discern where it’s most effective to put city sustainability efforts. It also shows how everything is related, how for example, building materials have embodied impacts in the form of water use, so the local context can be taken into account. Cities like Charlotte, Boulder, and Rotterdam are using material flow analyses as a foundation for strategic sustainability decisions.
Urban Mining Assessment
Mapping the ‘urban mine’ can help cities increase resource efficiency, by identifying valuable resources available for reuse within city borders, instead of importing new virgin materials. The tool is perhaps best understood through the lens of construction, where secondary building materials are identified and become available for reuse when buildings are demolished. In this context, raw data of what is in each building is most valuable.
“Something as simple as using someone else’s materials becomes a lot more scalable if you have the data for it.” – Arjang Tajbakhsh, Metabolic Industries Consultant
For example, BAG database in the Netherlands contains the age, shape, year of construction, floor spacing, and function of each building. By adding materials like copper and glass, it’s possible to reuse these materials at their highest value. The Dutch cities of Amsterdam, Amersfoort, and Dordrecht are actively using urban mining assessments to plan for future circular economies.
City data becomes most useful once it’s translated into action, and spatial analysis plays a particularly important role for this. While it’s essential to understand what impacts are taking place in a city, it’s equally important to understand where these impacts are taking place, so that interventions can be targeted accordingly. City neighborhoods have different characteristics, and different solutions might fit one neighborhood better than another. For example, high energy-using industrial neighborhoods might focus on closing energy loops with local renewable energy solutions, while areas focused on waste collection and processing might focus on measures to mitigate pollution and ensure community health and wellbeing.
Spatial analysis can help to ensure that interventions are weaved into the existing fabric of the built environment and are used in the most fitting context. Within the city of Amsterdam, spatial mapping tools are being used to inform new urban development as well as connect waste streams to circular business opportunities. In addition, Metabolic’s Circular Cities Program is currently piloting spatial methodologies to drive circularity in the Polish cities of Lublin, Warsaw, Krakow, and Gdansk.
Getting the most out of data
As much as data provides a robust foundation for evidence-based decisions, its real value is unlocked in combination with qualitative groundwork, and not as a replacement thereof. On-the-ground context is essential, and talking to people on the street will always provide a unique perspective of what is happening in specific areas. Using the combination can reveal correlations that might otherwise be difficult to understand. For example, in Nigeria, a change in land use led to more violence. The data collected created an understanding of the system and connections within it, while on-the-ground research with local stakeholders provided the necessary knowledge on causality. This shows how data and groundwork can strengthen each other with groundwork providing the detail and data the overview.
Without data, each city is acting individually, potentially putting effort into places that take a large number of resources or that may lead to unintended negative side effects, while many cities around the globe face the same common challenges. At the same time, current structural issues can hold cities back in taking a data-driven approach, as the end-goals often benefit different stakeholders than those who pay the costs, and the benefits are largely visible in the long term. Necessary policy changes and long term commitments could help cities overcome these barriers.
The Metabolic Cities Program works with individual cities to drive focused action while connecting them with other cities that have similar goals, to stimulate shared learning and accelerate results.
Global access to data for a bigger picture
One of the overarching benefits of data is the ease with which it can be used to communicate across borders. It allows cities to communicate with one another, comparing data sets, sharing learnings, and gaining insights into best practices. Through further standardization and the use of tools that allow cities to drive their own transition, it’s possible to accelerate collaborative progress. With the number of cities in the world rising, there is a lot to gain from data sharing.
When data is activated, it has huge potential to ground decisions for more accurate results. Because certain approaches have more impact than others, and one decision can provide a better result than another, it’s important to make each decision with qualified information and measure its progress. Data provides this science-based starting point with a systems overview, enabling change-makers to take actions that provide the most enduring impact.