A comprehensive survey of the environment has been called for by a group of 18 delegates to stop conflicting 'official' figures being published on issues such as expansion of desert areas. Niu Wenyuan, a CPPCC member and director of the Chinese Academy of Science's Sustainable Development Group, spearheaded the motion after he found his work thwarted by the lack of consistent data about China's environment. Mr Niu cited conflicting figures - which ranged from 2,150 to 2,600 square km - about the degeneration of wilderness into desert as an example of the difficulties experts face in combatting environmental degradation. 'These are all figures publicly released by relevant authorities, so which one is truly accurate?' Mr Niu was quoted as saying in a Beijing Morning Post report. Mr Niu said that in the absence of a national environmental census, efforts to try to understand one of the country's most important resources had been inconsistent. 'In the past 50 years we've had five population censuses and two natural resource general surveys, but we've never surveyed the ecological environment,' he said. Another initiator of the legislation was Ye Wenhu, an official from Beijing University's Centre for Environmental Science, who surmised the lack of clear data about water resources helped officials avoid dealing with the issue of contamination. The proponents of the move said a general ecological survey was urgently needed to implement laws on environmental protection.