A low-carbon economy calls for a circular economy, said Zhou Changyi, director general of the Department of Energy Conservation and Comprehensive Resource Utilization under the Ministry of Industry and Information Technology. He was delivering the keynote speech at the Green Economy TIO Summit in Beijing on Wednesday.

A circular economy is best achieved by extending the lifespan of daily products, Zhou said.

"However, in this aspect, we fall far behind," Zhou said. "It's quite common in Germany that a generator is still in use after having operated for 100 years."

Zhou said today's buildings are also a great waste. "We should strive for more buildings with a history of 100 years or more," he said. "Now, buildings in many cities have a life span of only 20 to 30 years."

Zhou said the second and third priorities in a circular economy are reusing products and recycling waste. Instead of everyone owning his own thing, people should reuse a common product, he said. He cited two objects: cars and washing machines.

"What if those cars were managed just like buses?" Zhou said. "Only when necessary do we drive them."