A panel session was held Friday on the sidelines of the ongoing United Nations (UN) climate change conference in Paris, also known as COP21, to discuss the opportunities and challenges for Chinese cities in their transition to green and low-carbon development.

Titled "Cities of the Future: Innovation and Sustainable Urbanization in China" and hosted by the American think tank Paulson Institute, the session saw mayors of Beijing, Shenzhen, Wuhan, Guiyang and other Chinese cities gather in the Paris City Hall to share their strategies for and achievements in pursuing sustainable urbanization.

The mayors also discussed opportunities in improving energy efficiency and establishing green finance mechanisms to bridge the price gap between sustainable and traditional technologies.

UN Secretary General Ban Ki-moon's Special Envoy for Cities and Climate Change Michael Bloomberg, who is also the former mayor of New York City, said in the opening speech that China has been ahead of the curve in recognizing the pivotal role cities play in fighting climate change.

Acknowledging Chinese cities' leading role in mitigating the impacts of climate change for years, Bloomberg said, "because of the huge populations, their decisions had a major impact on the globe."

"Cities have the ability to act swiftly, experiment with bold ideas, and share solutions that work," he said. "When national governments make commitments on climate change, it is cities that are going to deliver the results."

Over the past 20 years, China has accounted for 52 percent of the world's energy conservation, and its development of renewable energy technologies has helped cut global renewable energy costs.

Xie Zhenhua, China's special representative on climate change, praised the contributions made by local governments, cities and enterprises to overfulfilling China's national targets in combating climate change.

He said that since 2010, China has identified six low-carbon pilot provinces and 36 low-carbon pilot cities, tasking them to develop their own low-carbon roadmap based on their specific situation.

This panel session would enhance understanding between China and the world on low-carbon urbanization, open a new chapter of city-level cooperation, promote global action in fighting climate change and bring positive energy to the ongoing COP21, Xie said.

The discussion was part of a one-day Climate Summit for Local Leaders co-hosted by Paris mayor Anne Hidalgo and Bloomberg, which was described as the largest gathering of global mayors to discuss climate change.