Pearl River Delta city cluster in China's southern Guangdong province will step up efforts to build a green transportation system as the region moves to reduce carbon emission and protect the environment.

By 2020, more than 85 percent of buses in the region will be new energy vehicles, of which over 75 percent will be electric. The goal was released on Thursday during the 5th International Low Carbon City Forum in Shenzhen, Guangdong province.

"The PRD region, as the pioneering area of China's reform and opening up and also the country's demonstration area in green and low-carbon development, will fully implement Shenzhen Declaration (on the matter), accelerate to promote green and low-carbon development and work with Hong Kong and Macao to build a world-class city cluster that is ecological, beautiful and internationally competitive," said Wu Daowen, deputy director of Development and Reform Commission of Guangdong province.

It will also create a green industry system by 2020, with added value of tertiary industry accounting for 60 percent of the region's gross domestic product.

Added value of modern service will account for 65 percent of that of the whole tertiary industry by the same year.

The PRD region covers nine cities in Guangdong province -- Guangzhou, Shenzhen, Zhuhai, Foshan, Dongguan, Zhongshan, Jiangmen, Zhaoqing and Huizhou.