In 2010, Low Carbon City Development Guidance was made to support the initiatives of local authorities, by indicating what should be considered when promoting low-carbon city development, its basic concepts, as well as the necessary measures and methods of assessing their effects.

The Guidance consists of three parts: “Part I: Concept of a Low-Carbon City” sets out the rationale for creating low-carbon cities. “Part II: Low-Carbon City Development Measures” describes the methods in developing a low-carbon city in three sectors, namely transportation and urban structure, energy (private homes and private businesses), and greenery. “Part III: Analysis of the Effects of Low-Carbon City Development Measures” explains the methodologies for assessing the effects of the measures.

Especially, the guidance indicates the rational of converting to an intensive urban structure, as well as efforts in the three sectors of transportation and urban structure, energy, and greenery, on creating low-carbon cities.

In the transportation and urban structure sector, a compact urban area where people can live closer to their workplaces is expected to reduce travel distances and alleviate transportation demand. Reduced travel distances, in turn, will promote a shift from passenger cars to bicycles or walking. Moreover, increasing the density of traffic demand can raise the profitability levels of public transportation, thereby improving its service levels, which can further promote a shift from automobiles to public transportation.

The diffusion and proliferation of urban functions have caused problems at both the levels of global environment and living environment. It is feared that they will lead to the increased use of private cars and longer traveling distances, a resultant increase in CO2 emissions, and a greater load being placed on the environment. Another problem is that road congestion in built-up areas will be further aggravated, placing an even heavier burden on living environments.

In order to cope with global warming problems, it is necessary to implement not only a single measure such as improvement of housing environment, but also a comprehensive measure in urban areas. However, there was no established way to compare objectively how we combine several policies to make a city more effective as a whole.

Low Carbon City, Compact City, CO2, Congestion, Infrastructure, Rural, Environment, Planning

City Bureau, MLIT Japan