From avoiding smoggy runs to breathing freely under vivid blue skies, China's air-quality transformation amazes Erik Solheim, former UN under-secretary-general. How did this green transformation happen? With this question in mind, Solheim visited Anji, a county in Zhejiang Province in east China – the birthplace of the "two mountains" concept that's behind the huge change. Now back from his green quest, Solheim is in Zhejiang International Studies University to share his discoveries with the students there.