From the car-obsessed cities of the 20th to the cities of the 21th century. One is being built in China now

These new megacities could evolve into sprawling, polluting megaslums. Or they could define a new species of world city. Unlike New York or London, they are blank slates — less affluent, perhaps, but also free from legacy designs and technologies tailored to the world of the 19th and 20th centuries. That is a huge advantage. It took Boston 20 years and more than $14B just to reroute a freeway underground. New York can hardly install a second network of water pipes. Most of Los Angeles is too spread out for fast public transit or combined heat and power plants. And because these cities are so isolated from agricultural land, most of the food that locals eat gets shipped 100s of km. “Shanghai today is making 90% of the mistakes that American cities made” — spreading out, building up single-family homes, replacing naturally mixed-use neighborhoods with isolated zones for living, shopping, and working, and connecting it all with car travel. But fixing these problems is still possible. Dongtan breaks ground later this year on a plot about the size of Manhattan on Chongming Island.

2012-07-03: CO2-negative cities. It is well-understood that per-capita resource usage is lower in urban areas than in rural ones, and the first CO2-neutral cities are coming online. Covering vertical surfaces with plants would allow for CO2-negative cities.
2012-07-05: The first eco city, Dongtan, is so eco-friendly it doesn’t even exist.

Dongtan was a planned development described as an eco-city on the island of Chongming in Shanghai, China. Design began in 2005, and by 2010 the development had stalled. The project has been described as a failure.

2021-04-24: Green NYC

Global design firm WATG periodically rolls out speculative GIFs demonstrating how famous urban stretches can be realistically green-ified

2021-11-12: Not sure why it took so long for this to get a bit more traction, but here’s a proposal:

Urban Sequoia achieves substantially more significant CO2 reductions than has been achieved by applying these techniques separately. These strategies can be applied to buildings of all sizes and types. For cities, SOM’s prototype design is a high-rise building that can sequester 1000 tons of CO2 per year, equivalent to 48k trees. The design incorporates nature-based solutions and materials that use far less CO2 than conventional options and absorb CO2 over time. Materials like bio-brick, hempcrete, timber, and biocrete reduce the CO2 impact of construction by 50% compared to concrete and steel. A progressive approach could reduce construction emissions by 95%.

2021-11-13: Another, more ambitious concept:

Carlo Ratti Associati (CRA) has unveiled a project dubbed “the world’s first farmscraper,” to be built in Shenzhen, China. The 218-meter-high, 51-story Jian Mu Tower will contain a large-scale farm system with the ability to produce crops to feed 40k people per year, as well as offices, a supermarket, and a food court. The scheme’s façade consists of a 10k-square-meter vertical hydroponic farm extending the entire height of the building, estimated to produce 270k kilograms of food per year. The Jian Mu Tower seeks to “establish a self-sustained food supply chain” where the cultivation, harvest, sale, and consumption of food takes place under 1 roof.