The Asian Green City Index, commissioned by Siemens, analysed the environmental sustainability of 22 major cities in Asia with respect to environmental and climate protection.

"Of the 22 cities, Delhi generates the lowest per capita waste. The city's advanced policies, including one of the more robust strategies to reduce, reuse and recycle waste, also demonstrate how much can be achieved with limited resources," the survey found.  

The survey also found Singapore to be Asia's greenest metropolis. The city stands out in particular for its ambitious environmental targets and its efficient approach to achieving them.

"Asian cities produce less waste per capita than Europe and Latin America, but waste collection is less effective. The 22 Asian cities generate an average of 380 kg of waste per person per year, compared with 465 kg in Latin America and 511 kg in Europe," it found.

India's IT hub Bangalore was found to have the lowest levels of per capita carbon emissions as 30 percent of what the city consumes comes from renewable energy and 61 percent of the electricity is generated from renewable sources, mainly hydropower.