Using an index developed by multinational management consulting company Chinese Academy of Sciences and Accenture Plc, 100 cities were examined on their resource and environmental sustainability.

Indicators such as water and energy consumed per GDP unit, the recycle rate for industrial waste, emissions of sulfides, the intensity of fine particulates in the air and carbon emissions per capita were used to determine which city is the most energy efficient.

Here's ten best performing cities according to the study.

10 Hangzhou

A night view of the West Lake and properties surrounding it in Hangzhou, Zhejiang province. [Photo/IC]