How much green is really “cool”? Target setting for thermal comfort enhancement in a warm, humid city (Jakarta, Indonesia)

Green infrastructure is well recognized as a key urban climate mitigation strategy. In line with this, and following a central government decree, Jakarta Municipal Government has created a green infrastructure target of 30% underpinned by a green space weighting factor. This study questions the efficacy of such a “universal” target setting from the point of view of outdoor thermal comfort and demonstrates the basis for an alternative approach. Based on a “new’ green factor developed from a systematic analysis of the literature, thermal comfort simulations of representative local climate zones (LCZ) show that improvements in current green space policy are possible. We enumerate a rational basis for specifying green space targets per local area based on contextual realities as captured by the LCZ approach. Such a nuanced approach to mitigate the human comfort consequences of inadvertent urban growth is not only more contextually appropriate but also enhances the feasibility of achieving the intended goal of urban greening in Jakarta.