Grist: China has given environmentalists a lot of encouraging signs in recent years. Its highly polluting heavy industries have been slowing down, as has its coal consumption. In November, President Xi Jinping announced that the country would take steps to allow its emissions to peak around 2030, while simultaneously ramping up renewables. Increasingly, it seems like the country may be on track to hit that goal even earlier -- perhaps by 2025.
But now, Chinas economy has hit a rough patch. Its stock...