Building sustainable urban systems for the future

A. Urban Growth and Projections


The urban population of the world is increasing rapidly. It can be seen from the graph above that about 39% of the world’s population lived in urban areas in 1980. By 2015, it increased to 54% and it is estimated that urban population growth will reach 66%.


Currently (2018), the most urbanized regions include Northern America (with 82% of its population living in urban areas in 2018), Latin America and the Caribbean (81%), Europe (74%) and Oceania (68%). The level of urbanization in Asia is now approximating 50%. In contrast, Africa remains mostly rural, with 43% of its population living in urban areas (UN).


The UN DESA notes that “together, India, China and Nigeria will account for 35% of the projected growth of the world’s urban population between 2018 and 2050. By 2050, it is projected that India will have added 416 million urban dwellers, China 255 million and Nigeria 189 million”.

With an increasing urban population comes the various challenges, ranging from housing, transport, energy to employment issues. One of the consequences of urban population growth is the increase in the number of megacities. A megacity is a city with one 10 million inhabitants.

Cities ranking

Tokyo is currently the world’s largest city with a metropolitan population of about of 37 million, followed by New Delhi, 29 million, Shanghai, 26 million, and Mexico City and São Paulo, each with around 22 million inhabitants. It is expected that by 2020, Tokyo’s population will begin to decline, while Delhi is projected to continue growing and to become the most populous city in the world around 2028 (United Nations).

By 2030, the world is projected to have 43 megacities with more than 10 million inhabitants, most of them in developing regions. However, some of the fastest-growing urban agglomerations are cities with fewer than 1 million inhabitants, many of them located in Asia and Africa. While one in eight people live in 33 megacities worldwide, close to half of the world’s urban dwellers reside in much smaller settlements with fewer than 500,000 inhabitants.(United Nations)

Screenshot_2018-09-23 WUP2014-Highlights pdf
Source: United Nations, 2014

Urbanization facts. pdf

B. Resilient City Design

The increasing number megacities, resulting from the growth in urban populations, means that cities must develop effective systems to manage the problems that might characterize megacities. One way of managing the challenges associated with large cities is the concept of urban resilience.

A resilient city is one in which the individuals, businesses, communities and institutions have the capacity to survive, adapt and grow notwithstanding the challenges or shocks the city experiences.

The concept was developed by the Rockefeller Foundation called 100 Resilient Cities Project. The City Resilience Index is has been developed by the foundation to measure a city’s level of resilience. It has four dimension, 12 goals, and 52 indicators. This is summarized by the OECD in four broad pillars of measuring resilience.

List of 100 resilient cities


  • A diverse number of industries
  • A dynamic economy to generate growth
  • Conditions allow innovation to take place
  • People have access to employment, education, services, skills training.
  • Clear leadership and management
  • Strategic and integrated approaches are taken by leaders
  • Public sector has the right skills
  • Government is open and transparent
  • Society is inclusive and cohesive
  • Citizens’ networks in communities are active
  • Neighbourhood is safe
  • Citizens enjoy healthy lives
  • Ecosystem is sound and diverse
  • Infrastructure can meet basic needs
  • Adequate natural resources are available
  • Coherent policy towards land use

Source: OECD

Measuring Resilience. Source: OECD
Measuring Resilience. Source: OECD

More recently, the World Bank has added another dimension to the the Resilient Cities Concept – which is Managing disaster risks and impacts of climate change. The Bank’s contribution on urban resilience aims to equip cities to adapt to a broader variety of strategies to mitigate the shocks and stresses while maintaining essential functions (World Bank).

Strategies to manage escalating climatic and geopolitical risks to urban areas

Case Studies: Two detailed examples to illustrate possible strategies

  1. Rio de Janeiro’s resilience strategy to manage escalating climatic risks

Rio de Janeiro, is the second largest city in Brazil. With a population of about 11 million, it is a megacity with an increasing number of people migrating from the rural areas to the city. Consequently,the city is faced with a number of challenges, ranging from social inequalities to the development of fevalas (slums) on steep slopes around the city. The city is also faced with a lot of challenges posed by the climate change, including:

  • effects of flooding due to heavy rainfall
  • strong winds,
  • heat islands developed over the city
  • droughts
  • sea level rises and coastal flooding

The city is a member of the 100 Resilient Cities network and one way of tackling the climate – related challenges is to develop a number of resilient strategies:

Goal 1: Better understand and mitigate impacts of severe weather and climate change through:

  • the establishment of Rio de Janeiro’s climate change panel

This panel, pioneer in Latin America, is inspired by a similar initiative in New York City, and its mission will be to investigate, publish and communicate results of climate change research and its impacts on the city of Rio, as well as provide support for decision-making on urban planning and inform other fields of knowledge and the civil society.

The Panel aims to incorporate state of the art scientific knowledge on climate, at global and national levels, in order to indicate possible climate change scenarios and its impacts specifically to Rio de Janeiro and its metropolitan region. The reports released should foster scientific research on the effects of climate change at city level and foster conversation on the related environmental, social and economic aspects.

Furthermore, the Panel encourages a connection between climate change and other disciplines, with focus on transversal analyses of impacts, for example: a) analysis of how extreme temperatures impact vector-borne diseases such as Dengue, Chikungunya and Zika, b) economic valuation of various scenario-based impacts of sea level rise. The knowledge generated will support public policies for the mitigation and adaptation of climate change in Rio, specifically those related to strong rains and winds, sea level rise, heat islands and waves, droughts and epidemics.

  • Implement a portfolio of climate change mitigation

Develop a portfolio of projects for mitigation and reduction of GHG emissions, and also adaptation projects to reduce the existing and future effects of climate change, suited for public, private and international financing. This portfolio must incorporate the conclusions related to climate in the local level, as informed by the Rio de Janeiro Panel on Climate Change (initiative 1A).

Having as a basis the citywide GHG emission inventories and the Climate Change Adaptation Municipal Plan, led by the Secretary of Environment, the city of Rio will develop a portfolio of actionable projects focused on targeting the greatest emitters, with the establishment of goals, and fostering better management of resources though the promotion of a circular economy (initiatives 5A and 5B). The plan for mitigation and reduction of GHG emissions will involve projects related to renewable energy, low-carbon economy and sectors, and transportation.

The Portfolio of Climate Mitigation and Adaptation will aim to provide guidelines for urban interventions of Rio de Janeiro, so that urban planning, public works and maintenance internalize concepts and practices that make Rio more resilient to climate change. Those projects will be related to rainfall harvesting, permeable paving, tree planting, green roofs, among others (see Goal #3, “Cultivate green, cool, safe and flexible urban spaces”), and must be formulated already considering available and innovative financial options.

The portfolio’s objective it to foster the development of projects to tackle the vulnerabilities of the city to strong rains and winds, heat islands and waves, sea level rise, epidemics and accidents with urban infrastructure. The first stages for the implementation of a portfolio of climate mitigation and adaptation is featured in the Strategic Plan 2017-2020 and Rio Resiliente supports its development on an amplified scope.

  • Monitor climate change trends and impacts

Monitor and support research on climate trends and impacts, analyzing socioeconomic data in order to generate crosscutting analyses of costs and benefits of projects and public policies for climate. The risk modelling will be developed with the support of geo-referenced risk mapping (initiative 1D), involving shocks and chronic stresses such as strong rains and winds, heat islands, air quality, flooding and landslides, high tides and storm surges, and epidemics.

The aim of this initiative is to establish permanent, integrated and multidisciplinary climate monitoring, with the involvement of city departments, other spheres of government, NGOs and citizens. To this continuous and evolving monitoring, other analyses will be added, for example, such as the social and economic impacts of sea level rise in the next decades. This initiative also entails the monitoring of the winds in the city, for the development of historical data and support for academic research on the theme, adding to the existing knowledge about rains. Finally, this project supports research on the interactions of heat waves and heat islands with the air quality of Rio.

Furthermore, the monitoring of climate trends and impacts involves the active participation of citizens, through the voluntary and collaborative collection of climate data with the use of simple homemade sensors, thus supporting actions of Citizen Science.

This initiative, including the monitoring and Citizen Science, was proposed by Rio Resiliente and incorporated by the Strategic Plan 2017-2020. It is currently partly being implemented, as the Center of Operations is stating to monitor heat waves and incorporate wind data already, and partly in the planning phase, for example for the sea level rise studies

  • Mitigate multi-hazard risk map

Develop multi-hazard assessment mapping, with the use of computational models, real-time sensoring and Big Data, for better integration of the main risks that affect the urban space of Rio. These maps aim to support analyses about possible interactions of risks in the urban space, mainly but not limited to those related to intense rains and winds, heat islands and waves, air quality, flooding and landslides, high tides and storm surges, epidemics and accidents with urban infrastructure.

The aim is to identify the interactions between climate-related challenges and other types of risks in the city, in order to form a solid knowledge basis for public managers, academia and cities. It must allow for a comprehensive visualization of risks and their impacts in the region, to help identify priorities for intervention. For example, it is known that excessive heat and pollution can diminish the lifespan of concrete structures, with implications in the durability of urban infrastructure. Moreover, rain flooding and overflowing of rivers can affect mobility. Therefore a map with storm flooding patterns is supported by Strategic Plan 2017-2020 (Initiative 3.10, Flood Control). The Center of Operations Rio monitors in real time the heat waves of the city. These two types of maps constitute examples of risks that will be present in the multi-hazard assessment maps, which will allow for studies on cascading effects.

With the support of Big Data, historic data from sensors and climate scenarios, these integrated climate risk maps become sophisticated tools for urban planning and, in case of crises, for the deployment of sufficient and adequate first response. This initiative promotes the collaboration between public departments and public concessions. This initiative is currently being implemented by Rio Resiliente in its early stages and was fully incorporated by Strategic Plan 2017-2020.

For further details on Rio’s strategies to mitigate the challenges posed by climate change, click Rio de Janeiro’s Resilience strategy

2. Cardiff, United Kingdom: resilient-cities-cardif

Overview of Cardiff

Cardiff’s administrative structure

The city of Cardiff is the capital of Wales. The metropolitan area of Cardiff is part of the Cardiff Capital Region, and consists of five local governments, with the city of Cardiff functioning as the core area.

Challenges for Cardiff’s resilience

  • Global competition in need of skilled workers while integration of lower skilled labour is critical

The challenges of sustaining its current growth include ensuring the availability of skilled workers and ensuring quality of life that will attract and retain them. Wages below the UK average in Cardiff in general are a drag on the attraction and retention of skilled labour and graduates from Cardiff’s universities. Despite strong growth in jobs in financial and business services, attracting high-wage service jobs has been a challenge. Cardiff is competing with other economic centres for high-paying service jobs, such as London. Furthermore, the need to integrate low-skilled workers into the economy is growing, since demand for unskilled employees is falling except in the retail and hospitality sectors.

  •  Building a compact city with a growing inflow of population

Strong employment growth has increased the need for housing in the city. However, Cardiff has only limited space for new housing and may experience a shortage in housing. Approximately 41% of the city’s area is protected from urban development to preserve green spaces and most brownfield land has already been developed. Meanwhile, the River Taff and the coastal plain is subject to the risk of flooding, and tidal and fluvial land limits the space available for housing. New construction in the city needs to take into account the impact of climate change and compact city development. To accommodate this demand, more compact forms of urban development are called for.

  • Social disparity in a growing city

While economy in Cardiff grows, socio-economic disparities among citizens have increased in recent decades. The generalised deprivation index, assessing health, crime and access to services, shows that 7 of the 10 lowest-ranking “super output” areas in Wales are located in Cardiff. The coastal zone of Cardiff and the Vale of Glamorgan attract prosperous population, and the more disadvantaged valleys of South Wales.With the construction of new flats and office buildings, low-income housing areas are gentrifying, driving up property prices and forcing lower income groups out of the city.

Elements for building resilience in Cardiff


The city attracts investment in its key business sectors and workforce, notably through the creation of an “enterprise zone” in central Cardiff that offers relief on business taxes; and by involving Cardiff University in the city’s development.


Meeting the demand for affordable housing by planning for well-designed, connected and sustainable communities through the Corporate Development Plan (2014).


A public transport network has been developed to increase access to jobs. The so-called “Metro project” aims to improve cross-regional connectivity and to provide better-quality transport.


The city’s mid-term vision – Corporate Plan 2015-2017- shows the targets of Cardiff of becoming “Europe’s most liveable capital city”.

Policy coordination for more efficient land-use planning in the Cardiff metro region has been explored, with the creation of the Cardiff Capital Region Board (2013) which brings together representatives from the public and private sectors on an advisory board. A new project, City Region Exchange, aims to bundle the region’s capacities and promote engagement between the city and the region.


  • Cardiff has put forward a strategy to improve the horizontal co-ordination of policies with adjacent municipalities in the Cardiff Capital Region. In particular concerning housing and transportation services, this strategy facilitates better access to public transit and jobs, and helps to mitigate the pressure on the housing market within the city of Cardiff as people living in neighbouring communities can access jobs within the city more easily.
  • The closer integration of policies across the Cardiff Capitol Region also improves the attractiveness of the region for business and for younger people to remain in the area, but also to address some of the social inequalities in the area. The better integration of transportation options helps lower income groups to have access to jobs across a larger area as well as younger people to settle in affordable areas and commute to their job location.
  • Further encouraging the capacity building of marginalised groups through close co-operation with the local community to improve access to employment opportunities could be pursued.

Case study adapted from OECD

3. Kyoto, Japan :resilient-cities-kyoto

C. Eco City Design

Eco cities are cities that are designed to be environmentally sustainable. A city is environmentally sustainable when resources are used in meeting the needs of the present population of the city without compromising the ability of future generations to meet their own needs.

Rogers (1977) developed a model to describe a city’s sustainability. He compared a sustainable city with an unsustainable one and he described the latter as “linear metabolism city” and the former as the “circular metabolism city.”

Source: Slideshare

According to Rogers (1977), the circular metabolism cities are much more sustainable than the linear metabolism cities. This is because the Circular Metabolism Cities are compact cities which minimize the distance traveled, use less space, requires fewer infrastructure (pumps, pipes, roads, cables, etc.) and are easy to provide for public transport network. Additionally, compact cities reduce the need for urban sprawl and therefore minimize the challenges facing urban areas. It involves management strategies that take into consideration the following:

  • Social management e.g housing quality and crime
  • Economic management e.g jobs and income
  • Environmental management e.g air, water, land and resource

Unsustainable cities, on the other hand, cover a large area and become over-crowded, over-priced, polluted and hence unsustainable.

To ensure sustainability, eco-city design must embark on the following:

  • Operates on a self-contained economy, resources needed are found locally
  • Has completely carbon-neutral and renewable energy production
  • Has a well-planned city layout and public transportation system that makes the priority methods of transportation as follows possible: walking first, then cycling, and then public transportation.
  • Resource conservation—maximizing efficiency of water and energy resources, constructing a waste management system that can recycle waste and reuse it, creating a zero-waste system
  • Providing sufficient green spaces – gardens and parks, rather than attempting to destroy it
  • It must ensure decent and affordable housing for all socioeconomic groups
  • It must attempt to achieve full employment
  • It must make a effort to reduce poverty
  • It must stimulate economic growth
  • It must operate efficiently with a high population density

One way to measure the sustainability of a city is by using its ecological footprint. It refers to the amount of land and water a city requires to produce the resources it needs and at the same time manage its waste under prevailing technology. The ecological footprint of urban areas is generally higher than rural areas.

Case Study: Tokyo’s ecological footprint

“Tokyo” as defined here is a conurbation region that includes the 23 wards of Tokyo Metropolitan Government and the surrounding prefectures of Kanagawa, Chiba and Saitama (Yokohama city is therefore included within Kanagawa prefecture.)

With this definition, Tokyo population was 26.6 million for 1995. The total population of the country was 125.1 million (1995). The total land area of Japan is 377, 700 sq km. (37,770,000 ha) (habitable land is equal to 125,500 sq km or 12,550,000 ha, approximately 33% of the total land).[ One World ]

According to the Earth Council report, “Ecological Footprints of Nations” a biologically productive area of 1.7 ha is available per capita for basic living. This means that for sustainable living, the people in Tokyo alone need an area of 45,220,000 ha – which is 1.2 times the land area of the whole of Japan. If mountains and other regions are discarded and only habitable land included, then this becomes 3.6 times the land area of Japan.

From the same report, taking the country as a whole, Japan has a demand for 6.25 ha per capita (for resources such as energy, arable land, pasture, forest, built-up area, etc.). But the supply has been 1.88 ha per capita. This leaves an ‘ecological deficit’ of 4.37 ha per person that has to be met from outside the country. For Tokyo alone, this is equal to 116,242,000 ha or 3.07 times the land area of Japan.

Other measures include the Sustainable Cities Index (SCI) and the carbon footprint. The Arcadis Sustainable Cities Index charts the average of three sustainability factors to rank 100 of the world’s major cities. Cities can be explored by overall rank or region.

  • People (Social)

Rates health, education, income inequality, work-life balance, ratio of wage earners to dependents, crime, housing, and living costs

  • Planet (Environmental)

Energy consumption and renewable energy share, waste management, green space, sanitation, water, greenhouse gas emissions, natural catastrophe risk, and air pollution

  • Profit (Environmental )

Transport infrastructure, ease of doing business, tourism, GDP per capita, the city’s importance in global economic networks, Internet connectivity, and employment rates

Case studies of eco-cities: Two detailed examples to illustrate possible environmental strategies

  1. Case study of sustainable cities: Copenhagen

Copenhagen is a coastal city in Denmark that is leading the way in sustainable development. Through innovative technologies and policies, they provide the globe with a model for mitigating human’s impact on the earth. Copenhagen aims to be Carbon Neutral by 2025

  • Integrating Climate into Energy Supply
  • Greener Transport
  • Energy Efficient Buildings
  • Copenhageners and Climate
  • Climate in Urban Development
  • Adapting to the Future Climate

For further details on Copenhagen, click Copenhagen:Becoming one of the most sustainable cities in the world

2. Download Case study of Masdar City

  1. Tokyo City, Japan
  2. Chicago City, USA

D. Smart Cities Design

A smart city is a city that incorporates information and communication technologies (ICT) to enhance the quality and performance of urban services such as energy, transportation and utilities in order to reduce resource consumption, wastage and overall costs. (technopedia)

The smart city is designed to use the Internet of Things (IoT) , which involves a digital network of interrelated devices such as buses, trains, houses,  buildings, machines, sensors and computers that have the ability to transfer data over a network without the need for human to human interaction. Data is obtained directly and directly. Directly, it is collected from devices designed for such purposes. E.g from machines or sensors that collect data on traffic flows, length of queues, location of buses, parking spaces available. etc (Codrington, 2018). Indirectly, data is gathered from the internet such as social media discussion etc.

Examples of IoT devices include smart car, wearable, smart appliances, smart city, smart buildings, smart health, smart farming, smart home, smart television etc.

Source: theinternetofthingsagenda

Smart city technology operates on five main principles

Infrastructure– The infrastructure of a smart city must be able to adapt ot changing conditions. Achieving this goal requires equipping the infrastructure with sensors that can monitor traffic flow, energy consumption, movement of people and water consumption. For example Amsterdam’s street lights are regulated according to the weather conditions. In London, driverless trains are controlled by a network of sensors





Advantages of smart cities include

  • Smart cities help to overcome the problem of older settlements isolating people living them. ICT has led to the development of communication that links people of different socioeconomic groups together using digital bridges of communication
  • monitor their overall business processes;
  • data can help administrators and planners decide which services can be obtained cheaply
  • improve the customer experience;
  • save time and money;
  • enhance employee productivity;
  • integrate and adapt business models;
  • make better business decisions; and
  • generate more revenue.

The disadvantage of smart cities is that

  • they can be very expensive,
  • city managers may not be able to give priority to data privacy and security,
  • the presence of security cameras may be seen as an invasion of privacy or government surveillance

Further reading:

Examples of smart cities:

  1. Singapore: The world’s most smartest city
  2. Copenhagen:


One reply on “Building sustainable urban systems for the future”

I have recently started a web site, the information you provide on this site has helped me greatly. Thank you for all of your time & work.


Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

This site uses Akismet to reduce spam. Learn how your comment data is processed.