China and the U.S. finished a major two-day meeting on climate change in Los Angeles on Wednesday. Yang Jiechi, Special Envoy to Chinese President Xi Jinping and U.S. Vice President Joe Biden were both at the meeting.

Leaders from 14 Chinese provinces and cities also participated in the meeting and signed a series of cooperation agreements with their U.S. counterparts on emissions reduction targets.

China, the world’s second biggest economy, promised to cut carbon dioxide emissions per unit of GDP by 60 to 65 percent by 2030, from 2005 levels.

To meet that goal, an estimated 6.7 trillion U.S. dollars will be needed to improve energy efficiency and develop renewable sources. Over 50 provinces, cities and municipalities have been chosen as pioneers to carry out the transformation.

“The experience and lessons accumulated by these pioneer cities in the eastern, central and western parts of China can be references for other cities,” said Xie Zhenhua, China’s special representative on climate change.

The meeting fulfils a key element of the China-U.S. Joint Announcement on Climate Change by the two presidents last November.

Further cooperation on climate change between the two countries is also one of the three key topics to be discussed during Chinese President Xi Jinping’s upcoming visit in September.