Anyone who has spent any length of time in northern China knows the plight: Sandstorms from the deserts of Mongolia and Kazakhstan turn cities like Beijing and Harbin into a nicotine-yellow soup at least once a year. On Monday, it was that time again. Some 409 million people had to brace themselves with masks and tightly closed windows against the weather phenomenon gnashing between their teeth. Beijing’s air pollution index rose well above the scale’s upper limit to 1300 on Monday evening, and visibility dropped to a few dozen meters, giving sights like Yonghe Temple a spooky aura.