GUANGZHOU -- Carbon emissions allowances closed at 28.42 yuan ($4.06) per ton on Tuesday, 2.19 percent up from Monday, at the China Emissions Exchange (Guangzhou), the largest local carbon market in China.

A total of 168,101 tons of allowances were transacted on Tuesday, with a turnover of 4.964 million 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 155.93 million tonnes of GDEA, with a total turnover of 3.128 billion yuan.