 The trees are the best technology to solve our problem in cities. Bosco Verticale is the first example of a family of a new idea of architecture who doesn't simply use green as an ornamental component. We are reducing the heating of the city, absorbing the CO2, we are absorbing the fine dust produced by urban traffic. We are reducing the consumption of energy. It's hard to breathe in Milan, it's hard to breathe in Beijing, it's hard to breathe in Frankfurt, it's sometimes hard to breathe also in Boston. So we have a common issue all over the world. We are taking calculation on how much the tree grows and consequently how much carbon they fixed. In the two towers we have more than 25,000 plants on both the towers. Vertical 4 is one of the I think most important and efficient way to reintroduce nature inside the cities. When we started to understand how to maintain the system there were just one way to do it. We asked to have professional team of arborists to take care of trees, not exactly gardeners but arborists. And they jump outside and they move in vertical. So we had a lot of reaction from the point of view of the residents. Someone is looking and someone is saying, okay yes you look strange but you are doing a good job. Someone is offering coffee. Us as architects we cannot escape from our responsibility of builders of urban environment. So climate change is a very serious issue, it's a very serious issue and if you really want to deal with this issue we have to think seriously how we can contribute. It's also a way to give to the inhabitants also from a psychological point of view a sense of comfort that normally we don't have when we live at 80, 100, 150 meters. The plants, the flowers, the little birds that live in them can somehow create emotions, also a sense of relaxation. In the future I think we will need to imagine also the realization of real forest cities. So cities that will be composed by buildings all with trees and place on the facades. I really hope that many other architects, many other urban planners, many other politicians will be in condition to replicate and improve what we have done because I think that the vertical forest is a serious contribution to improve the quality of air, to improve the quality of life in our cities.