GUANGZHOU, March 16 (Xinhua) -- Carbon emissions allowances closed at 39.5 yuan (about 5.72 U.S. dollars) per tonne on Monday, remaining unchanged from the last transaction day at Guangzhou Emissions Exchange.

A total of 51 tonnes of allowances were transacted on Monday with a turnover of 2,011.3 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 233.41 million tonnes of GDEA, with a total turnover of 6.79 billion yuan. ■