The United Nations board that manages carbon trading has suspended approval for dozens of Chinese wind farms due to questions of eligibility, the Financial Times reported. China is currently the largest beneficiary of the carbon-trading system known as the Clean Development Mechanism (CDM) which directs funds from wealthy nations to developing nations to cut greenhouse gasses. In the past five years, China has earned 153 million carbon credits worth US$1 billion, almost half the total issued by the UN. The credits are currently trading at US$10-15 each. Under the current system, applicants for credits must prove that their project could not go ahead otherwise, a condition known as "additionality." Concerns have been voiced that Beijing has lowered subsidies for projects in order to receive more UN funding. A Chinese government spokesperson denied such allegations. These and other problems with the CDM system will be discussed during the Copenhagen climate change conference, which begins on Monday.