As Xi Jinping, China’s president, told other world leaders in Paris that their talks mark a “new starting-point” in tackling climate change, his own capital was stewing in a pea-souper of smog. Yesterday Beijing’s air-quality index topped 600: “Hazardous…everyone may experience…serious health effects”. (Paris’s reading: 24.) China’s climate negotiator, Su Wei, sounded a note of urgency: “Time is quite pressing; we will make every minute and second count.” As its contribution to the proposed treaty, China’s government is offering several targets, most of which it was going to meet anyway. In Beijing the environment minister, Chen Jining, proudly announced that China had met those in its current five-year plan six months early. But their worth is open to doubt—and not only because of the smog. Luo Jianhua, of the China Environment Chamber of Commerce, an NGO, said official figures had underreported sulphur-dioxide emissions in 2014 by nearly half.