Comparative studies of urban climate co-benefits in Asian cities: an analysis of relationships between CO2 emissions and environmental indicators

This study examines the factors that explain cross-sectional variations in per capita emissions of one of the primary greenhouse gases (GHGs), carbon dioxide (CO2), in major Asian cities. Why do individuals in Bangkok, Thailand, produce an average of 6.1 tons of carbon dioxide annually, but individuals in Shanghai emit 9.7 tons of CO2? Why do CO2 emissions per capita vary across twenty-two major Asian cities? To what extent are relevant environmental indicators associated with CO2 emissions? To answer these questions, we begin by reviewing the climate co-benefits of existing environmental indicators (waste, green space, water, public transport and energy use) and climate change. Based on a literature review, we hypothesize that cities with higher resource use and wealth will have higher CO2 per capita emissions. To test the hypotheses, we analyze the relationship between tentative co-benefits of existing environmental indicators and CO2 emissions per capita using regression analysis. We find that a city's energy inefficiency, waste generation per capita, and GDP per capita are positively associated with CO2 emissions per capita, while we control for a battery of variables such as population and industrial structure. Our findings suggest that enhancing energy efficiency and reducing waste generation are effective ways to mitigate climate change while also realizing climate co-benefits.