Policy Driven Compact Cities: Toward Clarifying the Effect of Compact Cities on Carbon Emissions

Compact cities, characterized by high density and accessibility with fully developed inner-city public transport, are widely discussed and practiced around the world in response to the challenges of sustainable development and global warming. On this basis, we are committed to answering the question of how cities with varying urban growth rates adopt different policy practices, and whether these practices contribute to achieving the goal of building a sustainable, low-carbon city. Specifically, this study assesses the theoretical evidence and practical experiences on the effect of compact city characteristics and policies on urban CO2 emissions using a focused literature review and representative case studies. The results illustrate that public transportation is often strengthened in compact city policies and the density and spatial configuration of cities has a significant impact on urban carbon emissions. Moreover, there are significant differences within the impact mechanisms of compact cities on carbon emissions between small-medium-sized cities (dealing with aging populations and resource waste) and megacities (dealing with excessive urban sprawl). However, there is still insufficient quantitative evidence on the effectiveness of compact city policies and this review provides insights into future compact city planning toward policy approaches which yield lower carbon emissions.