A City Trapped in a Thermal Cage--Heat Islands and the Agony of Architects (May 2004)

A City Trapped in a Thermal Cage--Heat Islands and the Agony of Architects (May 2004)

The 2004 roundtable discussion on the urban environment, "The Housing Architecture Debate in the Heat Island," was a debate among architects, environmentalists, and government officials on how to respond to the rapidly worsening phenomenon of urban warming, or heat island effect, from their respective perspectives.

At the time, Tokyo and other large cities were experiencing "urban heat islanding," a phenomenon in which not only daytime temperatures rise but also nighttime temperatures cannot be expected to fall, and air conditioner use had become the norm, causing household electricity consumption to soar. This has led to questions about the sustainability of the power supply system and urban life, and the Ministry of the Environment and various local governments have been vocal about the need for mitigation measures.

The first to speak at this roundtable discussion was an architect. He argued that "improvements at the level of individual housing are the closest environmental measures that citizens can take." He said that building with natural materials, such as the use of insulation, airy floor plans, and rooftop greenery, would achieve both living comfort and environmental friendliness. In contrast, the environmentalist emphasized the need for a master plan that looks at the entire urban structure, saying that "individual housing improvements alone cannot change the heat flow in an entire city. He considered the fact that densely populated residential areas have been left unimproved as a contributing factor to heat islands, and argued that the "absence of urban planning" is the root of the problem.

In this discussion of individual versus city and micro versus macro, the government official's remarks were tinged with the color of a coordinator. He stated, "Citizen approval is essential to make it mandatory through ordinances and regulations." He also took a cautious stance on rooftop greening, for example, saying that although there are incentives available through subsidy programs, social consensus is needed to make it mandatory. In fact, although some municipalities were offering greening subsidies, the low utilization rate indicated the difficulty in gaining public understanding.

The three parties' statements sometimes intersected and sometimes ran parallel. Architects said that "sustainable improvements cannot take root at the expense of comfort," while environmentalists countered that "reliance on air conditioning and artificial cooling accelerates global warming as a result. The government interceded, "It is precisely in order to get closer to the citizens that we should start with the mechanism. This conversation was not merely a technical discussion, but encompassed the question, "Who will envision the future of the city?

This debate vividly illuminated the dilemma facing Japanese society in the early 2000s: the dichotomy between "urban sustainability" and "civic comfort. The heat island phenomenon is not merely a weather phenomenon, but also a mirror that reveals the relationship between cities and people, and this roundtable discussion provided an opportunity to reexamine the nature of this phenomenon.