The World Wide Fund for Nature (WWF) on Thursday welcomed China's announcement of specific figures for a reduction in the carbon intensity of its economy by 2020.

"A 40-45 percent reduction in China's carbon intensity from business as usual projections is far from trivial," said Kim Carstensen, head of WWF's global climate initiative.

"Given the size of China's economy, the decoupling of China's economic growth from growth in emissions is one of the most important factors that will determine whether the world can get on course to keep temperature rise below two degrees Celsius," Carstensen said in a statement.

"This new announcement from China is worth several gigatons of avoided emissions to the atmosphere," he added.

The Swiss-based environment conservation group also welcomed the Chinese announcement on Thursday that Premier Wen Jiabao would attend the Copenhagen climate summit next month.

"The world needs a legally binding agreement, and we need leaders like Wen Jiabao to come to Copenhagen to make that happen," Carstensen said.