The long-term impacts of air pollution control policy: historical links between municipal actions and industrial energy efficiency in Kawasaki City, Japan

Under the pressures of rapid industrialization and urbanization, many Asian countries are facing the challenge of reducing air pollution and CO2 emissions simultaneously while maintaining their economic growth. Under such a circumstance, a growing attention is focused on successful implementation of co-benefit policies that are designed to reduce both air pollutants and CO2 emissions. However, the concept of co-benefit policies must be developed further in order to identify its quantitative and qualitative validity, which can be assessed using a reliable methodology for the estimation of co-benefits and through clarification of the importance of this approach for stakeholders in urban environmental policy-making. Based on a systematic review of co-benefit research and air pollution control policies in Japan, we investigated the local air pollution control policy in Kawasaki City, one of the industrial centers of Japan, and confirmed that it has contributed both to the sharp decline of atmospheric sulfur dioxide (SO2) levels and to energy efficiency improvements in local industries. Our results suggest that preventive actions and local-scale compliance enforcement tools (that are uniquely designed and act as a form of agreement between government and individual firms) could contribute significantly to successful implementation of co-benefit policies in the long-term. We conclude our paper with a discussion of linkages between low-carbon technology innovations and policy designs that could further nurture co-benefits.