Climate Desk: ON A HAZY MORNING LAST SEPTEMBER, 144 American and Chinese government officials and high-ranking oil executives filed into a vaulted meeting room in a cloistered campus in south Xian, a city famous for its terra-cotta warriors and lethal smog. The Communist Party built this compound, called the Shaanxi Guesthouse, in 1958. It was part of the lead-up to Chairman Maos Great Leap Forward, in which, to surpass the industrial achievements of the West, the government built steelworks, coal mines, power...