An empirical study on the relationship between urban compactness and CO2 efficiency in China

This analyzes the relationship between urban compactness andCO(2) efficiency in China. A quantitative indicator of urban compactness andCO(2) efficiency (CO2 economic efficiency andCO(2) social efficiency) was selected and calculated using remote sensing and panel data analysis. According to data from 30 cities, urban compactness is correlated positively with urbanCO(2) economic efficiency, which is measured by the ratio of GDP to totalCO(2) emissions. Conversely, the compactness ratio shows a negative correlation with urbanCO(2) social efficiency, which is measured by the ratio of social welfare indicators to total CO2 emissions. These results indicate that, within China, designing compact low-carbon cities could lead to an increase in urbanCO(2) economic efficiency. However, if the compactness ratio is too high, the increased compactness accompanied by various socio-environmental problems will result in a decrease in urbanCO(2) social efficiency. Therefore, compactness entails a trade-off and this should be considered by policymakers. (C) 2013 Elsevier Ltd. All rights reserved.