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Green Cities That Grow from Within

News that a group of ultra-wealthy venture capitalists were secretly buying up agricultural land outside the San Francisco Bay Area got a lot of people talking.1 It was finally revealed that this was a project called California Forever, a plan to build a sustainable, technologically advanced city from scratch. But, it’s not the first idea of its kind.

Ideas to create new eco-cities are popping up around the world2, with ambitious plans for solving all urban problems at once. Smart Forest City near Cancun, Mexico, is an eco-efficient smart city planned for 130,000 people to live in homes surrounded by trees and covered with 7.5 million carbon-absorbing plants.3 The architecture studio that designed Chengdu Future City claims it will be the car-free capital of China's Sichuan province.4 And The Line in Saudi Arabia has already broken ground. The 170-kilometer-long, 500-meter-tall linear city for 9 million inhabitants is already being called “the least-efficient possible shape of a city.”5

Start where people live

Cities are complex and their problems are legion. The desire to start from scratch is understandable. If nothing else, pristine plans and AI-generated visuals create a lot of buzz. But inherent in the new city movement is the idea that it’s just too hard to change existing ones. The issues are real. According to the United Nations Human Settlements Programme (UN-Habitat), cities “consume about 75% of global primary energy and emit 50 to 60% of the world’s greenhouse gasses.” The second figure “rises to around 80% when indirect emissions generated by urban inhabitants are included.”6

While planned cities promise a fresh start, as of 2022 existing cities were home to 57% of the world’s population.7 In North America, Latin America, and the Caribbean, more than 80% of people live in cities. In the spirit of the admonition that there is no planet B for earthlings, the vast majority of city dwellers have limited alternatives. And they’ll have to figure out how to accommodate a lot more neighbors, since 70% of the world’s population is expected to live in cities by 2050.

Cities are laboratories of innovation, where ideas for improving livability are tried, tested, and scaled. They have no choice but to change through the broadest possible involvement. As an organization engaged in the pursuit of climate solutions, Onward fosters and supports the kind of collective action that will move humanity toward a sustainable energy future.

Collective action within and between cities

To get an idea of how collective action works at the street level, we looked at local environmental initiatives that are manifesting change in real living cities. We found inspiring examples at C40, a global network of mayors from the largest cities united in action to confront the climate crisis.8 The following examples are just a few interesting case studies that demonstrate how solutions that start in the community can make an impact on a global scale.

Microtransit makes a macro impact

The Indonesian capital of Jakarta and the surrounding metropolitan area are home to 32 million people. Transjakarta, the region’s public transport system, has traditionally been augmented by an informal fleet of microbus operators. To reduce emissions, congestion, and air pollution while expanding transit coverage and ridership, the transit authority introduced a program to incorporate microbus service into the formal transportation network.9 Microbus operators were provided with upgraded vehicles that are being transitioned to electric. Riders benefit from an integrated fare system that makes multimodal trips easier and cheaper.

Jakarta’s microbus fleet is far from micro. It accounts for more than 60% of the transit fleet and connects residents in the critical “last mile” portion of their trips. The microbus project has enabled the city to double public transport coverage from 42% in 2017 to 82% in 2022 and to increase daily ridership from 300,000 to over 1 million passengers. Jakarta’s transit authority attributes the project’s success to intensive and ongoing collaboration among regional leaders, microtransit operators, transit agencies, and city government representatives. Public support was also key. The project was promoted to citizens for its economic, social, public health, and climate benefits.

Transjakarta now shares the results and best practices of their microbus program so other cities with informal transit sectors can adopt similar models that benefit riders, operators, and the health of the city.

When you can’t take the heat

People move to Arizona for the warm weather. But climate change has been delivering heat that can be too much for even the most ardent sun lovers. In 2023, Phoenix recorded the hottest day ever for any U.S. city, along with 31 days of temperatures in excess of 110° F (43° C). In response, the Phoenix suburb of Tempe worked with local high school and university students, teachers, and ASU’s Indigenous Design Collaborative to introduce nature-based solutions to help cool the city.10 The Cool Kids, Cool Places, Cool Futures project was inspired by community-focused youth coalitions in Morocco and New Zealand. The goal was to move heat resilience from an individual’s responsibility to a community response.

The students took training programs on environmental injustice and the impact of extreme heat in neighborhoods that lack tree canopies, green spaces, and access to nature. They learned about the historic and present-day realities of Tempe residents — especially displaced Indigenous peoples. Then they studied Indigenous growing and farming practices, environmental justice, and the impact of extreme heat on vulnerable communities. Recognizing the importance of nature in heat mitigation, students at one local high school established a greenhouse and gardens on campus, planted desert-adapted trees, and used native species to create a bioswale for stormwater runoff. 

Collaborating on community sustainability projects like Cool Kids, Cool Places, Cool Futures can help residents feel more empowered and teach the next generation how to contribute to climate change mitigation.

Give a city a hand 

Tokyo is the world’s most populous metropolis, with 36.5 million residents. In a city known for its density, an estimated 70% of carbon emissions come from buildings. In 2010, the city instituted the world’s first mandatory emission-reduction program, the Tokyo Cap-and-Trade Program, which has reduced emissions by 33% with sustainable building materials, high-efficiency systems, and buildings powered by rooftop solar panels.11 Urban planners are also using strategic landscaping and planting to turn Tokyo into a green city that enhances livability for residents.

Since sustainability is a global problem, the Tokyo Metropolitan Government is partnering with other cities to share what they’ve learned about decreasing the carbon footprint in existing buildings. One city partner is Kuala Lumpur, the capital of Malaysia and the country’s largest and fastest-growing city. Tokyo officials helped those at Kuala Lumpur City Hall collect and document energy data. From that data, they could determine realistic carbon-reduction targets and identify the kind of equipment that would need to be installed or retrofitted to meet the city’s efficiency goals.

When city engineers at Kuala Lumpur City Hall needed to learn how to be energy-efficient and convert to renewable energy, there was no reason to start from scratch. Their collaboration with the Tokyo Metropolitan Government helped them focus on the initiatives that would make the most difference, so Kuala Lumpur could continue growing with sustainability at the forefront.

Collaboration leads to sustainable success

C40, in their Cities100 report, identified the factors that lead to successful sustainability initiatives like the ones we’ve summarized above.12 They found that 80% of the initiatives cited the importance of strong political will — the involvement of mayors and local leadership. In addition, 63% said stakeholder leadership was key and 51% pointed to the important role of local actors and community involvement. In other words: collaboration, collaboration, collaboration. Another intriguing finding was that 30% of respondents didn’t consider new technologies to be important to their project’s success — perhaps only new thinking.

The kind of collaborative innovation that’s happening at the city level is what inspires the Onward platform. We’re building an interdisciplinary ecosystem with the goal of connecting people with skills, ideas, and resources to address all aspects of the global energy transition. Onward is a community of scientists, students, entrepreneurs, professionals, and engaged citizens who are working together to build a sustainable energy future.

As for cities, it’s tempting to want to give up on them because they’re so frustratingly complex and hard to change. But while some people are making news with images of brand new technotopias, real cities are challenging the notion that nothing can be done. Doesn’t this seem like a metaphor for our planet? The problems humanity is facing won’t be solved by giving up or deciding that the home we have isn’t worth the effort. Innovative solutions are being worked on even now. The challenges are hard, but we can tackle them together.

Learn more about the Onward community and how to contribute to our planet-changing projects. 

1 Conor Dougherty and Erin Griffith, “The Silicon Valley elite who want to build a city from scratch,” The New York Times, August 25, 2023,

2 Nat Barker, “Ten futuristic cities set to be built around the world,” Dezeen, August 1, 2022,

3 Eleanor Gibson, “Stefano Boeri unveils Smart Forest City covered in 7.5 million plants for Mexico,” Dezeen, October 25, 2019,

4 Lizzie Crook, “OMA designs Chengdu Future City as ‘alternative to the typical masterplan,’” Dezeen, February 4, 2021,

5 The Complexity Science Hub Vienna, “Why Saudi Arabia’s ‘The Line’ is not a revolution in urban living,” Global Construction Review, June 23, 2023,

6 UN-Habitat, “Urban Energy,”

7 Statista, “Share of urban population worldwide in 2022, by continent,”

8 C40 Cities,

9 C40 case study, “How Jakarta integrated informal microbuses into the public transportation network,” September 2023,

10 C40 case study, “Cool Kids, Cool Places, Cool Futures in Tempe,” October 2023,

11 C40 case study, “Transforming Cities: The cities sharing big ideas,” February 2023,

12 C40, “Cities100 2019,” October 2019,

ThinkOnward  |  ThinkOnward Team

ThinkOnward is a nexus of innovation, collaboration, and energy entrepreneurialism focused on energy resilience and pursuing a net-zero future. We’re creating a hub for the “thinkers”, the “change makers” who want to foster new ideas, leverage and use powerful data and tools, and collaborate with the best scientific minds, together with investors and entrepreneurs committed to accelerating the commercial success of innovative energy and climate solutions. 

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