Boasting almost 15 sqm of surface area, combined with state-of-the-art IoT technology, the free-standing, 4-meter construct features special moss cultures that can scrub more NO2 and particulates from city air than 275 trees. What’s more, each CityTree also reduces our annual CO2 footprint by up to 240 tons, while requiring 99 percent less space and 95 percent less funding than regular city trees. All of these are relevant factors in face of the current acceleration of urbanization and the related, acute constraints placed on urban space and budgets. CityTree was developed by an interdisciplinary team of four with backgrounds in biology, information technology, applied economics, mechanical engineering, and architecture – all joined by 15+ years of friendship. In 2014, the quartet decided to join forces as Green City Solutions – and soon went on to sell several CityTree installations.