Who is a good neighbor? Analysis of frontrunner cities with comparative advantages in low-carbon development.

A well-developed economy and low-carbon emission intensity are important characteristics of low-carbon cities; they also represent important tasks for achieving global climate change mitigation goals. It is seldom discussed, however, how we should identify frontrunner cities from which low-carbon development experiences can be gleaned and then implemented in neighboring cities. This study, therefore, proposed a simple indicator-the "good neighbor index"-to identify frontrunner cities in low-carbon transformation based on economic and emission performance. Based on this indicator, we identified "good neighbors" in static and dynamic views for China. The results showed that the static good neighbors in 2015 were mostly large cities with higher incomes and better industrial structures whereas the dynamic neighbors achieved better economic growth and emission reductions from 2005 to 2015, though their economic and emissions statuses were generally worse. The good neighbor list is not consistent with the list of national low-carbon pilot cities, which has largely overlooked the experiences of some fast-growing cities. These results have policy implications for the Chinese government in terms of promoting the low-carbon transformation of cities. The study can also provide a reference for other countries in addressing climate change at the city level.