Shenzhen, south China's Guangdong Province, launched a carbon trading scheme on June 18, the country's first market for compulsory carbon trading.

The scheme covers 635 industrial companies and some public buildings that account for about 40 percent of the city's carbon emissions, the Shenzhen carbon trade exchange said in a statement.

Under the trading program, those that emit below their quotas could sell their excess limits to other emitters and even investors for profit.

The carbon intensity, or the amount of carbon produced per unit of GDP, of the 635 industrial companies in 2015, will slump 32 percent from levels in 2010.

Eight deals, or 21,112-ton carbon quotas, were traded on the launching day at prices ranging from 28 yuan ($4.6) to 32 yuan ($5.2) per ton.