Rebalancing Daytime and Nighttime Population

Google’s parent company, Alphabet, has a subsidiary for urban planning and innovation called “Sidewalk Labs”. Established in 2015, this company is headed by Dan Doctoroff, a former deputy mayor of New York City.

Sidewalk Labs is now designing a district in Toronto’s Eastern Waterfront. This project has caused a big controversy over the use of data and privacy. Setting aside this important issue, as this article is not intended for discussing data and privacy, it has to be noted that Sidewalk’s master plan, submitted on June 17, 2019, reveals various ways to create a nearly carbon-neutral city that cuts greenhouse gases by 85 percent. These include relying on clean energy sources for heating and cooling; optimizing energy consumption using digital technology; designing energy-efficient buildings; providing residents, workers, and visitors with a full set of transportation options including “not-owning a car”.

      (From Sidewalk’s “Master Plan” submitted on June 17, 2019)

Sidewalk’s ambitious plan is just one example. Today’s city planning has to cope with sustainability issues by striving to realize climate-positive urban developments through an innovative ecosystem.

Take a look at Tokyo from this perspective. The Tokyo Metropolitan Government (TMG), at the U20 Mayors Summit held in Tokyo in May 2019, declared that TMG will seek to realize a Zero Emission Tokyo to contribute to the goal of global net zero CO2 emissions by around 2050.

Tokyo’s energy-related CO2 emissions now amounts to 57 million tons, equivalent to the total emissions of Austria. One striking fact is that commercial buildings account for 45% of these emissions in Tokyo, whereas residential sector accounts for 30%, and transportation for 17%.

 

(Tokyo Metropolitan Government: “CREATING A SUSTAINABLE CITYTOKYO’S ENVIRONMENTAL POLICY” SEPTEMBER 2019)

Tackling emissions produced by the Tokyo’s commercial sector is the key to success for Tokyo’s endeavor toward zero emission city. From the environmental viewpoint, Tokyo has already too many commercial buildings than it can afford, and this is evident from a fundamental problem Tokyo now faces; namely a huge gap between daytime and nighttime population.

According to Tokyo Metropolitan Government’s “Tokyo Toshi Hakusyo (City View Tokyo) 2013”, the ratio of daytime and night population in the three central wards (42 square kilometers) of Chiyoda, Chuo, and Minato is 6.2 to 1.0, with the daytime population of 2.31 million versus the nighttime of 0.37 million. This figure is 1.3 (daytime) to 1.0 (nighttime) in Manhattan (59 square kilometers), New York, with the daytime population of 2.09 million versus the nighttime of 1.60 million.

This ratio is outrageously skewed in Chiyoda ward (14.6 to 1.0), with its daytime population of 853,000 and nighttime of 58,000. Every morning, about 800,000 people commute to this district from the outside by the commuter trains, buses and cars.

Disproportionately large daytime Tokyo population causes more-than-manageable CO2 emissions in the commercial sector, which accounts for 45% of total emissions in Tokyo.

It has also significant negative impact on the CO2 emissions in the transportation sector. Every morning, numerous commuter trains arrive at Tokyo’s terminal stations at intervals of 2 minutes. This is often favorably noted for its efficiency from the viewpoint of emission control. However, we have to look at the fact that these trains have to go back to the suburbs every 2 minutes with almost no (or at least very few) passengers on board.

There are about 1,000 convenience stores in Tokyo's three central wards. Many office workers buy lunch boxes and snacks at these convenience stores in Tokyo. Large number of trucks leave factories in neighboring prefectures for Tokyo every morning to deliver the lunch boxes to the convenience stores in the Tokyo’s central districts. These trucks return to the factories afterwards with little load.

Some policy measures or guidelines are strongly encouraged to limit the total space for commercial buildings and offices in the Tokyo central district in order to correct the disproportionately large daytime population. Residential use of the buildings in the form of condominiums and apartments should, on the other hand, be encouraged.

Institute for Urban Strategies of the Mori Memorial Foundation issued Global Power City Index on November 19, 2019. According to this index, Tokyo was ranked 23rd out of 48 cities around the world in the area of environment taking into account of the following nine indicators: (1) commitment to climate action, (2) renewable energy rate, (3) waste recycle rate, (4) CO2 emissions, (5) SPM density, (6) SO2 and NO2 density, (7) water quality, (8) urban greenery, and (9) comfort level of temperature. This study shows that much has to be done to accomplish the Tokyo’s aggressive goals set forth in the area of environment.

Correction of the distorted population structure of daytime and nighttime should probably come to the top of TMG’s to-do list as it is the fundamental basis to enhance the Tokyo’s attractiveness in the area of environment, and therefore, it should be the key to sustainable growth of this city.