Tokyo: The Emergence of Urban Desertification and Heat Pollution—May 1975

Tokyo: The Emergence of Urban Desertification and Heat Pollution—May 1975 The issues of urban deserts and heat pollution are new environmental problems born of urbanization in the 1970s. The document states in the May 15, 1975 issue, “Results of Two Surveys on Urban Deserts and Heat Pollution Announced… Urgent Need for Urban Greening,” indicating that the concretization and asphalting of cities were recognized not merely as a matter of aesthetics, but as serious issues causing rising temperatures and the deterioration of living environments. The term “urban desert” refers to a state in which soil, vegetation, and water bodies have disappeared from the city, leaving it covered entirely by artificial structures. As buildings, roads, parking lots, and industrial sites increase while trees, farmland, and open spaces decrease, cities become dry, hard spaces. In such environments, rainwater has difficulty seeping into the ground, and heat accumulated during the day tends to linger into the night. This phenomenon is similar to what is now known as the urban heat island effect. Asphalt and concrete readily absorb solar heat but, unlike plants, do little to cool the surrounding area by evaporating moisture. Consequently, urban areas with little greenery tend to have higher temperatures than surrounding regions, leading to discomfort in the summer, increased use of air conditioning, and worsening air pollution. Urban greening became an urgent priority during this period because greenery was reevaluated not merely as decoration, but as an environmental mechanism for lowering urban temperatures. Street trees, parks, private gardens, riverbanks, and factory green spaces play a role in creating shade, suppressing heat at the ground surface, and cooling the surroundings through water evaporation. Increasing greenery within cities was a practical measure to protect the living environment. Furthermore, urban desertification affected people’s sensory experiences. Urban spaces devoid of greenery bring not only heat and dryness but also a sense of oppression, fatigue, and a loss of seasonal awareness. In the urban greening discourse of the 1970s, there was a strong emphasis not only on pollution control and temperature regulation but also on restoring a humane living environment. In this way, the issues of urban deserts and heat pollution are important themes that demonstrated how urban development itself generates new environmental burdens. Urban greening came to be positioned not merely as a way to restore lost nature as decoration, but as a policy aimed at comprehensively restoring heat, air, water, scenery, and human comfort.