GUANGZHOU -- Carbon emissions allowances closed at 42.84 yuan (about 6.01 U.S. dollars) per tonne on Monday, 6.54 percent down from Friday, at Guangzhou Emissions Exchange, the largest local carbon market in China.

A total of 12,810 tonnes of allowances were transacted on Monday with a turnover of some 548,815 yuan.

The allowances, officially known as Guangdong Emissions Allowances (GDEA), are carbon dioxide emissions caps assigned to companies. Firms whose emissions surpass their share must buy extra quotas from authorities or purchase unused quotas on the market from those that cause less pollution.

Since its opening in December 2013, the market has traded 228.68 million tonnes of GDEA, with a total turnover of nearly 6.62 billion yuan.