The Bosco Verticale in Milan is taking green roofs to another level by planting trees along the sides of the skyscraper.  After completion it will be the greenest building in Milan, one of Europe’s most polluted cities.  The trees will provide a microclimate to filter out pollution dust particles, absorb CO2, produce oxygen, moderates temperatures, lowers new pollution, and lowers energy needed for heating and cooling.  Click here to view more pictures.