A trading scheme for developed nations to meet greenhouse gas emission reduction commitments while subsidizing new emission reduction projects in developing countries is on the verge of breakdown, according to a global energy think tank. Weak demand from Europe for emission credits saw only half of the scheme’s one billion tons of approved credits bought, with the other half waiting for buyers, said Joan MacNaughton, the London-based World Energy Council’s Executive Chair of Energy and Climate Policy Assessment. The possible collapse of the scheme could negatively impact Chinese wind power producers who earn more than 20% of their pre-tax profit from selling carbon credits to European firms. China Datang Corp Renewable Power reported that its carbon credit income plunged 52% in the first half, while that of Huaneng Renewables sank 71%. According to World Energy Council Analysts, if nothing was done to stimulate demand or restrict supply, the amount of excess emission credits would swell to between 3.4 billion and 4 billion units by 2020, from 500 million now, MacNaughton said. Governments should augment their emission reduction ambition and pool resources to buy up some of the excess credits, to help revitalize the carbon market, or risk its collapse. She said that despite some shortcomings, the system was considered a proven market-based method to reduce emissions globally. MacNaughton said China’s worsening global ranking in energy-consumption pollution control was likely to continue this year. It was ranked 87th out of 92 countries last year, worsening from 80th in 2010 in terms of its environmental impact mitigation performance, based on an annual assessment by the Council, the South China Morning Post reported.