While we have explored several solutions to promote sustainability in a variety of sectors in our previous articles, it is essential for us to shift our focus towards developing cities or communities that they may actively contribute to decarbonizing the atmosphere.

A sustainable city is conceived to tackle social, environmental, and economic challenges through effective urban planning and city management. Sustainable urban development plays a crucial role in future-proofing cities to become livable for people. In fact, the United Nations recognizes this as part of its 17 Sustainable Development Goals. Goal 11 focuses on creating cities and human settlements that are inclusive, safe, resilient, and sustainable. Increasing levels of urban development and pollution poses a challenge with 60-80% of energy consumption and 75% of carbon emissions attributed to cities. Hence, the goal is by 2030 to enhance inclusive and sustainable urbanization and capacity in all countries.

Sustainable cities must be a priority as resources dwindle and climate change impacts our world. Let's explore the essentials of sustainable cities.

Transportation

According to The National Resources Defense Council, 90% of cities emissions come from buildings and transportation sectors. Cars and other fuel-based vehicles contribute heavily to those emissions.

• Upgrading mass transit systems with reliable zero-emissions vehicles such as fuel-cell buses may incentivize individuals to opt for public transportation, while increasing the number of charging stations for electric vehicles can motivate people to transition from internal combustion engine vehicles.

• Cities can create pathways, bike bridges, and sidewalks to promote walking, and cycling as well. Aside from carbon emissions, these measures can also decrease congestion and enhance air quality and overall improve quality of life.

Housing

As mentioned, buildings also contribute significantly to carbon emissions and is at the same time vulnerable to climate change with its increasing levels of frequency and severity. As discussed in a previous post, decarbonizing housing begins with sustainable construction practices and extends to the equipment used to make homes livable.

• Bio-based materials such as bamboo, mass timber and wood can be utilized as raw materials to facilitate the creation of net-zero buildings. Wood can absorb one ton of CO₂ per cubic meter, while a hybrid cross-laminated timber building can reduce global warming potential by 26%.

• To better prepare for the increasing impacts of climate change, it is essential to climate-proof amenities and facilities. This includes installing specially glazed doors and windows for enhanced insulation and durability, as well as implementing rainwater harvesting systems to manage water resources efficiently.

• Renewable energy such as geothermal for heating and cooling can ensure lower carbon emissions and installing efficient electrical panels and backups to store energy to prevent power outage.

Food Security

Food insecurity occurs when access to an adequate, safe, and nutritious food supply becomes uncertain or unreliable due to economic or physical barriers. High bouts of drought, wildfires and rainfall have proven to destroy crops and livestock causing food shortage. Cities may have to start exploring innovative approaches to ensuring food security.

• Urban agriculture transforms underutilized spaces into lush, productive zones which includes rooftop gardens, community plots and advanced indoor vertical farms. This enables localized food production while simultaneously reducing the carbon footprint associated with traditional farming and long-distance travel.

• An example of this is Brooklyn Grange in New York, renowned as one of the world's largest rooftop soil farms, yielding over 50,000 lbs of organically-cultivated produce annually.

Waste Management

As the world continues to urbanize and its population continues to grow, municipal solid waste (MSW) is expected to double by 2025 (UN-Habitat, n.d.). Municipal solid waste encompasses recyclables, compostable materials, and general garbage generated by households, businesses, institutions, and construction and demolition sites.

• Mandatory recycling practices and proper waste segregation is an initial approach to efficient waste management. Many countries have introduced a deposit system for glass and plastic bottles in collaboration with retailers. Under this system, consumers pay a deposit when purchasing bottles and receive a refund when they return the empty bottles to designated retail outlets.

• Waste segregation is essential, but proper disposal is equally critical. It's not just about managing trash; other resources like water can also be repurposed. Biodegradable waste can help fertilize the soil, while used water can be reused for irrigation and toilet flushing through greywater systems.

Urban Areas

While the rapid pace of urbanization will require more housing, there is also a need to incorporate green infrastructure into the development process. Urban green spaces prevent urban heat, flooding, and other problems associated with climate change.

• Policymakers at the government level can consider the policy implemented by the US Department of Housing and Urban Development. Their Disaster Recovery Buyout Program enables localities to purchase commercial and residential properties in disaster-prone areas, converting them into park amenities, open spaces, or flood mitigation projects.

• If space is limited, pocket parks, plant-covered shaded pathways, sidewalks, and rooftop gardens are a way to increase oxygen levels and mitigate stormwater overflow. These green infrastructure solutions also enhance urban aesthetics, provide recreational spaces, and improve air quality. In addition, incorporating green walls and vertical gardens can further maximize the benefits of limited space in densely populated areas.

Two examples of sustainable cities are Berlin, Germany and Oslo, Norway.

Berlin, Germany

Since Germany's reunification in 1990, its residents have transformed the city's former ruins into parks and green spaces. GHG emissions in Germany have decreased by 40.4% since 1990 (Statista, 2023). Berlin, the country’s capital, is now considered the city of green trends and is progressing towards become a sustainable congress metropolis. What drives Berlin's sustainability is that it is deeply ingrained in the city's culture, rather than just being a trend. They simply follow the LOHAS principle (Lifestyles of Health and Sustainability), a conscious approach that integrates personal well-being, social responsibility, and environmental stewardship. Berliners actively seek opportunities for green infrastructure and nature-based solutions, supported by various green policies. Berlin aims to be climate-neutral by 2050 and is implementing rigorous measures to achieve this goal (Urban Sustainability Exchange, 2020). In every key aspect, Berlin is actively progressing towards sustainability:

Transportation

• The Berlin Senate has passed the Berlin Mobility Act in 2018 that aims to improve the efficiency and sustainability of different traffic elements such as public transport, bicycle traffic, pedestrian traffic, smart mobility, and general transport. This encourages the use of zero-emissions mobility options such as bicycles and e-bikes and renewable energy-powered public buses.

• EV charging stations have also climbed to 550 making the city lead in ranking in the whole of Germany and ensuring accessibility for EV owners, with a ratio of 1:3 EVs to one semi-public/public charging stations.

Housing

• Currently, wood houses make up less than 20% of all new homes in Germany. Wood is known to be a great carbon sinks so there is still an opportunity for Berlin to optimize wood for construction.

• The state-owned company Tegel Projekt GmbH is creating a new urban district from scratch at the decommissioned Tegel Airport. This development, part of the Berlin TXL project, will feature a residential sector, the Schumacher Quartier, with 5,000 climate-neutral apartments. The project will incorporate lumber sourced from forests surrounding the city into the construction of the residential area.

• Berlin Senate also introduced a comprehensive plan to advance the development of solar energy in 2020. This includes solar panels becoming a mandatory for installation since January 2023. New and existing buildings will have to install and manage photovoltaic systems as part of the plan. (Berlin.de, n.d.).

Food Security

• Embracing sustainability includes food for Berliners. Cucumbers are harvested in community gardens while honey from rooftop gardens as well vegan and vegetarian restaurants have been popping up in the city.

• Glass-walled vertical farming is the new approach for growing lettuce in the city. Start-up Infarm cultivates vegetables in indoor farms, providing fresh produce quickly and without wasteful packaging. These farming units are now present in retail trade, supermarkets, restaurants, and store rooms, totaling 50 units.

Waste Management

• Germany is celebrated as a world leader in recycling today because of its successful endeavor brought about by strong government policies and high awareness for recycling. Mandatory waste sorting and efficient deposit refund schemes have been highly effective for the country.

  • The Closed Substance Cycle and Waste Management Act makes manufacturers and consumers responsible for the prevention, reuse, recycling, and environmentally sound disposal of waste. Manufacturers are encouraged to produce recyclable, low-waste products. Recycling rates have risen, and the recycling culture is flourishing among the public.

  • The Deposit Refund Scheme allows consumers to pay a deposit when purchasing a bottle and be refunded when the empty bottle is returned to a retailer. Disposable plastics are also deliberately priced higher than the deposit on reusable glass and plastic bottles. The deposit system has had a 98.4% success rate since its inception.

Urban Areas

• The city's numerous public parks are integral to their way of life. Over 30% of the city area is composed of parks, gardens, trees, and navigable runways. With its cycling culture, the city also prioritizes biking paths.

• Decommissioned areas are turned into green spaces such as the Tempelhof Airport in 2010. Thanks to Berlin’s urban greening policy, old shunting yards and track lines are transformed into green spaces.

Oslo, Norway

Named as the European Green Capital in 2019 and has secured top place in the list of world’s most sustainable cities, its collaborative efforts and initiatives towards sustainability has made Oslo what it is today. Carbon emissions in Oslo has been steadily decreasing from 2009-2019, decreasing from 1.44 million tonnes to 1.14 million tonnes. Its success can be attributed to its dedicated climate budget to support opportunities for decarbonization and the cooperation of multiple stakeholders to achieve climate targets and cut down emissions across different sectors. In addition, Oslo's Climate Agency discovered that 70% of residents view climate goals as important and actively embrace them so their participation is also integral to its success (TheNewYorker, 2022). The city has identified that key sectors including waste incineration and energy supply (23%), private vehicles (33%), and other "mobile combustion" such as construction machinery (20%), contribute to nearly 80% of carbon emissions. Efforts to mitigate these emissions have been prioritized, although actions are also ongoing in other important areas.

Transportation

• Currently, Oslo has several fleets of electric mass public transport throughout the city – electric trams, buses, and ferries all of which are powered by electricity that is sourced from renewable energy. The aim is for all the city’s public transportation to become electric by the end of 2030.

• The city has also encouraged EV use among its private citizens through several incentives such as sales tax removal, free parking spaces, and free parking garages equipped with charging stations in buildings. As a result, Oslo now has been dubbed the EV capital of the world.

Housing

• Norway has been at the forefront of the replacement of steel with massive timber as construction material. The country strives to keep its forests sustainable with strict regulations, making Norwegian timber buildings the most environmentally friendly buildings in existence. In conjunction, the city of Oslo has set a target for all construction sites to be emissions-free by 2030 which puts pressure on property developers to use heavy-duty, electric construction equipment.

• Oslo also relies primarily on district heating from waste-to-energy incinerators and biomass-fired cogeneration plants to heat the city.

Food Security

• Oslo's policymakers are ambitious to transform the food system. They're particularly interested in climate-friendly food policies such as reducing meat consumption and food waste. Oslo is a participant of the EU-funded FUSILLI project that aims to transition towards sustainable food systems among 12 cities. Each city will create or enhance the development of a Living Lab, an open innovation ecosystem that deploys concrete actions to develop and implement urban food system policies.

• Organic and sustainable plant-based foods are also a priority for the city. It has increased the share of food with fair trade labels from 13% to 25%, and organic food from 2% in 2018 to 10% in 2020 (Modeshift, 2023).

Waste Management

• In 2006, Oslo launched its Waste Management Strategy (WMS) which aims to establish a “recycle and reuse” society. While paper and drink cartons are collected by the city, Oslovians are mandated to deliver glass and metal packaging to about 700 local collection sites around the city.

• Aside from proper waste disposal, waste is also repurposed to turn it into needed resources. Plastic packaging and food waste are sent to a biological treatment plant to produce enough biogas and biofertilizer to power 150 buses and provide biofertilizer to about 100 medium-size farms annually.

Urban Areas

• 50% of the city's emissions come from road traffic. In 2017, the city of Oslo piloted removing 350 downtown parking spaces and replacing them with bike lanes, sidewalks, and green spaces. This has been extended to key locations such as schools and parks. In addition, several major thoroughfares have been designated car-free.

Berlin and Oslo serve as inspiring examples for cities aiming to become sustainable. They have successfully reduced their environmental impact while ensuring comfortable living for their citizens. This achievement is due to the equal contribution of policymakers, the private sector, and residents, all working together to transform their cities. What also contributed to their success was gradually integrating different sectors of their cities into becoming carbon-free through various policies and incentives. Other countries can learn from Berlin and Oslo to initiate sustainable practices in their capitals and eventually expand them to other cities.

Sustainable cities require a holistic approach with these five key elements - efficient, emission-free transport, sustainable food production, eco-friendly housing development and practices, effective waste management, and green city spaces. By nurturing these 5 key elements, cities can reduce their environmental footprint, improve the quality of life for their residents, and create resilient communities that are able to meet the challenges of the future. GreenEco Investments is dedicated to supporting your efforts in developing sustainable cities. Partner with us to transform your vision of sustainable cities into a reality, ensuring a greener, more resilient future for all.