Why Future Cities Must be Green Cities: The Imperative of Urban Sustainability

The Urban Planet

For much of history humanity was mostly rural. Urbanization , started slowly during the Middle Ages, really taking off during the Industrial Revolution as masses of people migrated from rural areas to cities. The world’s urban population has since grown rapidly, and the peak is not in sight! Urbanization will continue apace for the foreseeable future, with the proportion of the world’s population living in cities passing two-thirds by 2050. Accordingly, ‘…the future of humanity is undoubtedly urban .”

Urbanization is not an inherently bad thing and has, indeed, brought humanity many benefits . Cities are vibrant, dynamic places, offering economic opportunity and sociocultural diversity, and serving as breeding grounds for entrepreneurship, innovation and development. These benefits have, however, come with serious costs. Modern cities are often characterized by high living costs, crumbling or inadequate infrastructure, chaotic and congested spaces, overburdened services, heightened climate and disaster risks, environmental pollution, socioeconomic inequality, insecurity and crime, all of which impact physical and mental health. They place an intolerable ecological burden on our planet through the massive resource inflows (energy, water and materials) required to sustain human activities within them, and the huge outflows of emissions and waste outflows the activities produce. This is more so in cities of Global South, where unrelentingly rapid urbanization comes up against limits imposed by endemic economic, social and environmental problems.

Green Cities – A New Urban Paradigm

These challenges, which have intensified with the growth and spread of urbanization, will certainly worsen without radical changes to the way we plan our cities. As we navigate the urban labyrinth of the 21st century, the concept of “Green Cities” has therefore emerged as a beacon of hope. A “Green City” is more than an urban environment adorned with parks and green spaces. It is a holistic approach to urban planning that encompasses economic, social, and environmental considerations to create sustainable, resilient, and livable urban environments. Green Cities integrate energy-efficient buildings, renewable energy sources, efficient waste management systems, water conservation strategies, sustainable transportation, and urban agriculture into their fabric. They promote integrated spaces and communities, encourage healthy lifestyles, and address causes of socioeconomic exclusion, offering a sustainable model for urban living that doesn’t compromise the planet’s well-being.

The Imperative of Green Cities

By 2050, two-thirds of humanity will be urban. This presents a problem, if we insist on continuing down the same urban development pathway, one premised on an unlimited supply of resources and the planet’s inexhaustible capacity to absorb our waste. Green Cities, which offer a pathway to urbanization's long-term viability and resilience, are more imperative now than ever for the following reasons:

Addressing the Climate Crisis

Cities have always been major players in the climate crisis , accounting for a staggering 75% of the world's greenhouse gas emissions while covering just 2% of the planet’s surface. Amid this crisis, though, cities are also a key part of the solution. Green Cities, through sustainable buildings and transport, renewable energy, and effective waste management, can drastically slash carbon emissions. Green infrastructure within these cities (e.g., green roofs, urban forests), can serve as carbon sinks, absorbing CO2 from the atmosphere, helping to slow the rate of global warming.

Managing Population Growth

According to the 2018 World Urbanization Prospects , the number of people living in the world’s cities is expected to increase by half (from 4.5bn to 6.7bn) by 2050. Green Cities are crucial to manage this urban influx in a sustainable way. Resource efficiencies embedded in their fabric and facilitation of sustainable lifestyles will substantially reduce the ecological impact of this huge mass of people. Considerations for integrated spaces, spatial justice, inclusivity, affordability, and access that are inherent in the planning of Green Cities will, furthermore, foster social cohesion, reducing the potential for stress and conflicts in these dense and crowded future cities.

Improving Public Health

The Green City model carries profound implications for public health and the quality of life of urban residents. By reducing air, water and noise pollution, promoting active lifestyles through walkable neighborhoods and bike-friendly environments, and providing spaces for relaxation and recreation, Green Cities greatly improve public health. During heatwaves or other extreme weather events, green spaces can serve as refuges. Numerous studies have shown that access to green spaces reduce stress and improve mental health. This is especially beneficial, with the adverse impacts of climate change on mental health. A recent study in Bangladesh , for example, found that ‘…exposure to natural disasters brought on by climate change…[increased the odds of]…depression by 31%, anxiety by 69%, and co-presence of both conditions by 87%.

Reducing Ecological Footprints

Green Cities reduce the burden urbanization places on Earth’s biophysical systems. Reliance on clean and renewable energy sources, promotion of recycling, rainwater harvesting, and vertical farming drastically reduce the consumption of natural resources. Green and blue infrastructure filter pollutants from city activities (e.g., transport) from the air and water. Improved waste and effluent management practices attenuate harmful metabolic outflows. Green Cities protect biodiversity by creating urban green spaces, serving as habitats for various species and forming an urban ecosystem that thrives amidst the city's hustle and bustle.

Catalyzing Economic Growth

Green Cities are not just good for the environment; they fuel economic growth and create wealth . By stimulating sectors like renewable energy, green construction, and sustainable transportation, they can create a wealth of job opportunities. Sustainable buildings and transport systems reduce resource demand and increase productivity, producing cost savings and increasing productivity. Property in green neighborhoods typically attracts higher valuations, creating wealth for lower- and middle-class owners. Moreover, the transition to Green Cities can attract businesses and talent, spurring innovation and economic growth.

Enhancing Urban Resilience

Climate change brings with it a host of challenges, including extreme weather events and rising temperatures. Green Cities, by design, are better equipped to weather these changes . Green and blue infrastructure can mitigate urban heat islands, manage stormwater, and reduce the risk of flooding. China's Sponge Cities , which incorporate permeable surfaces and green spaces that capture, filter, and store water, reducing flood risks and promoting water reuse, are an excellent example of how Green Cities can improve climate resilience. This increased resilience is vital in Nigeria and the rest of the world, where devastating floods and other extreme weather events have become an annual rite of passage.

Making Sustainable Lifestyles Easier

Don’t you often wish you could live more sustainably? Have you ever said to yourself, “If only….were available, I could do…?” Green Cities offer a solution to this conundrum, providing options that encourage adoption of or eliminate obstacles to personal sustainability . They make it easier for residents to recycle and compost, reduce water usage, and opt for sustainable means of transportation (mass transit, e-vehicles, walking, cycling) over driving. By making sustainable choices the easy choices, Green Cities can play a significant role in fostering more environmentally-friendly behaviors.

Green Cities – Our Collective Responsibility

As the world continues its march towards urbanization, in the midst of a global environmental and climate crisis, the concept of "Green Cities" is not merely a utopian idea but a survival imperative. While the journey may be challenging, the destination – a cleaner environment, healthier citizens, economic prosperity, and resilience in the face of environmental challenges – is worth the effort. Let us commit to Green Cities and ensure that the cities of tomorrow are green, vibrant spaces that nurture both people and the planet.

Join?Green Building Council Nigeria ?at the?Future Cities Summit 2023 ?at?Abuja Continental Hotel ?on?19-20 July 2023?as we envision the future of Nigeria’s cities as decarbonized and climate-resilient places, delivering healthy, equitable, and economically-inclusive spaces for every Nigerian, everywhere. Visit www.futurecities.ng to learn more and book your place for free.

The Author, Danjuma Waniko, is a Chartered Surveyor, Chartered Environmentalist & Green Star SA Accredited Professional. An enthusiastic advocate for environmental and social responsibility, Danjuma has been actively engaged in sustainability for over two decades, with a focus on green building. He currently leads Q Associates, a cost & sustainability consultancy firm he founded, and is President of Green Building Council Nigeria.