Despite congestion, dwindling resources and a high cost of living, people flock to cities on the order of 73 million per year. Accountable for at least 70 percent of the world’s GDP and for generating 75 percent of global greenhouse gas (GHG) emissions, rapid urbanization is challenging cities to innovate.
In response to the urgent climate crisis, there are numerous examples of cities worldwide that are being recognized and acknowledged as game changers for their efforts in the field of sustainable urban development. These cities have ably demonstrated not only the impact of ambitious and transformative planning and policy measures but have also followed through with context-specific infrastructure initiatives to foster mutually beneficial relationships between climate change mitigation, economic productivity and the improvement of the quality of life of citizens. Indeed, the advantages of upgrading to a Green City are far-reaching.
Climate-smart cities around the world: key sectors
Cities around the world can and ought to learn from one another. While solutions are context-specific, cities that are already at the forefront of delivering on their sustainability goals can lead through example by offering cumulative knowledge and inspiring other cities to follow suit. Visionary leaders embarking on a greening journey for their city can turn to evidence-based examples of proven success stories that stand to provide a much-needed fillip and a sense of reassurance.
Trendsetting sustainable cities demonstrate the power and payback of rethinking their approaches in key sectors. While department names representing key public infrastructure sectors can vary from one city to the other, we will refer to four: the built environment and energy, transportation, solid waste, and, finally, water and wastewater sectors.
From which cities can we draw inspiration for their efforts in these four sectors? Let's look at a few examples.
Climate-smart cities: built environment and energy
Typically, cities inherit old, carbon-intensive infrastructure. One of the most viable measures a city can adopt is to retrofit existing buildings to improve energy efficiency, thereby reducing carbon emissions. The indoor work environment – temperature, lighting, sound, ambiance – matters and impacts a firm’s productivity. Poor infrastructure, in fact, can reduce productivity by up to 40 percent.
Singapore’s green plot ratio (GnPR) incentive scheme encourages increasing the surface area of greenery as part of a Landscaping for Urban Spaces and High-Rises (LUSH) program. The function of external building surfaces becomes more than just structural; they become Landscape Replacement Areas (LRAs) – a growing medium for green space that impacts temperature and emissions, invites biodiversity and creates pleasant places to live and work.
One of Singapore’s 2023 green building targets is to green 80 percent of its buildings (by Gross Floor Area) in this manner, an ambitious but admirable goal that will benefit businesses, residents and visitors alike.
Another tried and tested example that can serve as an inspiration for other cities is Jakarta’s Green Building Code. This environment-friendly building code is a policy initiative designed to help Indonesia achieve a 29 percent reduction in GHG emissions by 2030. The code prioritizes greening the following building elements:
- “Behind-the-wall” systems such as electrical and HVAC;
- Outdoor and indoor landscaping;
- Rainwater capture;
- Construction materials and processes;
- Operations and maintenance;
- Water consumption; and
- Indoor air quality.
Figure 1. Jakarta's green building code will help Indonesia achieve its Nationally Determined Contributions of a 29% reduction in GHG emissions by 2030
Both Singapore’s GnPR incentive scheme and Jakarta’s green building code decouple economic growth and environmental impact to create a mutually reinforcing synergy between the two. Improving work and living spaces with greening measures and energy-reduction initiatives benefits productivity and attracts forward-thinking businesses to the area.
Climate-smart cities: transportation
Emissions from transportation are slated to increase at a higher rate than any other key sector between now and 2050, and it is difficult to decouple transportation-related carbon emissions from economic growth. Broadly, this means that an increase in GDP typically correlates to an increase in travel pollution, which is a real challenge faced by cities who wish to boost their economy and, at the same time, attempt to shrink the environmental impact resulting from ambitious infrastructure initiatives.
Implementing policy measures to decouple economic growth and the environmental consequence of travel is essential. That said, urban transportation is a sphere where even the most beneficial policies can be unpopular with certain segments of the population. Success stories do exist, however, setting the stage for other cities to emulate.
In Beijing, for example, a transport policy limited private vehicle driving to every other day. Supported by complementary policies (i.e. a quota on vehicle purchases, restrictions on the sales of used vehicles that failed to meet certain tailpipe emission standards, and increased investments in the public transit system), the every-other-day driving policy incentivized commuters to take advantage of public transit options, resulting in a 19 percent reduction in air pollution. The Beijing example powerfully demonstrates the importance of a supportive policy landscape.
Source: Wikimedia Commons
Climate-smart cities: solid waste
People produce, on average, 0.79 kilograms of solid waste per person per day. By 2050, this figure is expected to increase by two-thirds. Management of solid waste is a concern that plagues many cities, and a staggering 90 percent of waste is unmanaged in low-income countries. Given the environmental, health and safety repercussions of poor solid waste management, it is increasingly important for urban areas to consider both upstream generation as well as end-of-pipe management solutions.
The city of San Francisco offers an inspirational case study in solid waste management. Six short years following the implementation of an Environment Code, San Francisco cut its solid waste disposal in half. This extremely effective Environment Code was based on the “precautionary principle”, which states that if there is a significant environmental risk, then a lack of scientific certainty cannot justify inaction.
Well, this action allowed San Francisco to recover over 80 percent of its waste – exceeding its goal by 5 percent and 2 years early – and led to the adoption of an ordinance that required the recovery of construction and demolition debris. Seeing as the construction sector accounts for upwards of 40 percent of global GHG emissions, this was a policy action with measurable impact.
Success begets success and the positive waste management feedback loop in San Francisco continued with the adoption of a mandatory Recycling and Composting Ordinance that has now been in place for 14 years. This further paves the way for the City’s zero waste commitments by 2030, a laudable goal for a city that has demonstrated the outcome of good policy in mitigating environmental impact by adopting strategic solid waste management measures.
Figure 3. San Francisco has implemented innovative methods towards its zero waste commitment
Climate-smart cities: water and wastewater
Water, the most precious non-renewable resource, is set to experience a 50 to 80 percent increase in demand in cities by 2050. This means that urban water scarcity – where demand exceeds availability – stands to impact the health and socio-economic well-being of up to an estimated 4 billion urban residents by 2050.
As with solid waste, water and wastewater management must be considered from upstream use through to downstream processing. This is particularly important for urban areas where consumption needs are undeniable – scores of people live in cities and everyone needs water! Instead of looking at water and wastewater as a linear stream, it is possible to consider it as a circular system of use, capture, treatment and reuse.
In Namibia, the city of Windhoek distributes recycled wastewater as potable (i.e. drinking) water to its 350,000 residents and has done so for over a half-century. The novel treatment plant addresses both upstream and downstream concerns and reduces the consumption of water while also reducing pollutant discharge.
Namibia receives only 250 mm of rainfall per year on average. Given the hot climate, a mere 1 percent of this rainwater percolates into the scarce groundwater aquifer. The longevity of Windhoek’s Goreangab wastewater-to-drinking-water treatment plant demonstrates both the power of challenging environmental circumstances as a catalyst to act, as well as the feasibility and impact of a decidedly low-tech solution.
Figure 4. Windhoek is setting a global benchmark by producing drinking water from wastewater to secure its water supply
Climate-smart cities of the future: a valuable investment
When silos dissolve and boundaries flex, inter-departmental initiatives can take hold and mutually reinforce one another to bolster economic development. The idea is for the urban environment to function elegantly and in a streamlined manner in order to minimize congestion, waste and emissions so that it creates a robust, equitable and future-ready foundation on which to pin private-sector success and quality of individual and community life.
Having looked at examples of a few trendsetting cities that have successfully implemented low-carbon measures across the four key sectors, it is important to note that it’s not enough to look at a single sector in isolation. For optimum impact, city leaders need to consider the reduction in carbon emissions across all major sectors by prioritizing policy and planning measures and implementing appropriate actions according to geographical and financial contexts.
The importance of complementary policies and enticing incentives is crucial. Cities that transition towards a low-or-zero carbon future should simultaneously foster both economic and environmental benefits. A good Green City Action Plan covers all key sectors, proposes high-impact solutions and accelerates financial pathways to overcome challenges in order to realize projected benefits.
