Cities are key drivers of global economic growth and at the same time major contributors to environmental pressures. They generate around 80% of global GDP but also account for 70% of GHG-emissions, 75% of energy use and 60% of global material consumption. With the urban population projected to reach 6.4 billion by 2050, the way cities expand and develop will be decisive for global sustainability.
Dense and well-planned urban settlements can create significant economies of scale: more people benefit from shared infrastructure and services, reducing per-capita energy use, emissions, and costs. Sustainable urban infrastructure therefore plays a central role in enabling cities to grow while remaining livable: Integrating renewable energy, green technologies, and efficient public transport systems are essential to reduce emissions, enhance resource efficiency, and strengthen resilience to climate risks.
Urban sprawl, by contrast, drives transport-related emissions and air pollution, contributes to biodiversity loss, increases impermeable surfaces that worsen flooding, and often limits access to services for low-income communities. Reversing these trends and harnessing the potential of cities will require large-scale investments in sustainable, climate-adaptive infrastructure that supports both economic development and environmental protection.
Higher density of cities not only reduces transport-related carbon emissions but also reduces the extent of needed infrastructure networks.
Urban nature-based infrastructure solutions help cities achieve sustainability and contribute to a city’s resilience against extreme heat events, floods, and extreme rain. For instance, increasing the amount of permeable surface (e. g. sponge cities) increases a city’s ability to absorb rainwater. Parks and other green spaces also have direct physical and mental health benefits for citizens and contribute to the aesthetic value of the city and urban biodiversity and can be integrated into preexisting-built environment. Many cities have converted decommissioned rail lines into walkable linear parks. Klick here for more information on nature-based solutions.
TOD is a strategy of urban development that concentrates housing, jobs and amenities around public transport stations. This strategy increases the number of dense and walkable mixed-use neighborhoods, where services and amenities are available to residents within a 15 minute journey from home, greatly reducing the dependency on individual motorized transport. The main policy-instruments of TOD are zoning and land-use regulations (aimed at residential and business development) as well as transport infrastructure investments.
An estimateted 40 per cent of people do not have access to safely managed sanitation services. Especially in densely populated urban areas a working sanitary system is necessary to keep public health in check. Without proper sanitation hazards like pests and diseases such as cholera, worm infections and polio increase. An especially vulnerable group of inproper sanitation are infants and young children. A lack of sanitation can lead to stunted growth and underweight. Diarrhoeal diseases are the leading cause of death among children under five, despite being preventable through improved water and sanitation services.
To account for the growing housing needs in cities, large amounts of building material is needed. Embodied carbon, which represents the emissions caused by the production of building materials and the construction process, accounts for more than 25% of the emissions caused by a building over its life-cycle. The production of concrete and steel is a major carbon contributor in this process. Decarbonizing concrete and steel production or replacing them with less polluting alternatives can improve the sustainability of material use in the building sector.
Not only the material use, but the construction itself can become more sustainable by integrating principles of energy efficiently through better insulation, reduced heating/air conditioning, and even orientation to the sun.
Other well-documented green building techniques include the use of nature-based solutions like green roofs and facades. These methods present a wide array of benefits for the building and the environment, as they not only contribute to insulating buildings during winter, but cool buildings and their surrounding environment in summer, reducing urban heat island effects. They also catch fine airborne particulate matter, sequester CO2, reduce water run-off, and improve biodiversity.
LEED is a rating system that creates and certifies more sustainable and well-connected neighborhoods, through a holistic consideration of communities.
SuRe® is a verified, global voluntary standard for sustainable and resilient infrastructure development projects. Projects wishing to undergo SuRe® certification are subject to independent third-party initial certification and annual surveillance audits provided by an accredited Certification Body.
Envision is a flexible system of criteria and performance objectives to aid decision makers and help project teams identify sustainable approaches during planning, design and construction of infrastructure projects that will continue throughout the project’s operations and maintenance and end-of-life phases.