Business Green: China’s most senior negotiator on climate change said yesterday he was keeping an open mind on whether global warming was man-made or the result of natural cycles. Xie Zhenhua said there was no doubt that warming was taking place, but more and better scientific research was needed to establish the causes. Xie, Premier Wen Jiabao’s special representative on climate change, was speaking in Delhi at the end of a two-day meeting of ministers from four of the most powerful emerging …