The Nanjing vertical forest will be higher than its Milanese predecessor, with two neighbouring towers at 200 and 108 meters tall.

World Economic Forum | about a year ago
They could be the breath of fresh air that pollution-choked cities desperately need. Vertical forests – high-rise buildings covered with trees and plants – absorb carbon dioxide, filter dust from pollution and produce oxygen.

http://ewn.co.za/2017/05/05/china-is-about-to-get-its-first-vertical-forest