BBC: China’s lead climate change negotiator has said he was keeping an “open attitude” as to whether global warming was man-made or due to natural cycles. Xie Zhenhua said climate warming was a “solid fact” and that mainstream scientific opinion held it was due to emissions of gases such as CO2. He was speaking in Delhi at a meeting of envoys from Brazil, China, India and South Africa. They agreed to submit their plans to cut emissions by the end of January. The …