The main purpose of the new China Green Low-Carbon City Index (CGLCI, or City Index) is to evaluate the status of green and low-carbon development for a large number of Chinese cities. Chinese cities are formulating plans and implementing programs to address national initiatives, especially the national low-carbon pilot program for 36 cities and six provinces. However, there is not yet an established framework for measuring, reporting, or evaluating low-carbon progress across Chinese cities, despite the development of a number of Chinese and international city indicator systems. The new China City Index highlights energy use and carbon emissions of Chinese cities, along with environmental and socio-economic indicators. We selected metrics (indicators) that have data available in China’s statistical system, are commonly used internationally, and reflect Chinese policy goals. (See Table ES-1.) We then benchmarked and ranked Chinese cities in terms of their status and progress, identified potential areas for improvement, and identified top-runners.
 By “low-carbon” we mean reducing emissions of carbon dioxide (CO2) and methane (CH4), with a focus on energy-related CO2. The term “carbon” is used as short-hand for these GHGs throughout the report. By “green” we recognize multiple environmental parameters related to urbanization and climate change: air quality, water use, solid waste, transport networks, and urban green space.
 In early 2017, China expanded its low-carbon pilot cities program, adding 45 more cities.