Imagine looking out from your 18th floor apartment in the middle of the city and seeing trees right in front of you.

In an effort to stem climate change, reduce pollution, combat heat, and protect biodiversity, architects are teaming up with botanists, urban wildlife ecologists, and other scientists to design high-rise forests, living walls, and vertical farms in some of the world's most populated places. These projects are happening all around the world, and they will not only change the urban landscape, but they will provide urban dwellers with a healthier place to live and work.

For Buildings That Breathe, author and environmental journalist Nancy Castaldo connected with architect Stefano Boeri at the World Forum on Urban Forests and was invited to his office in Milan where she visited Bosco Verticale, the first high-rise forest. Planted with 750 trees, 5,000 shrubs, and 11 perennials on two apartment towers, the project provides an urban habitat for birds, insects, and people while creating a micro-climate that produces oxygen and provides shade for high-rise residents. Explore Bosco Verticale, as well the planned Liuzhou Forest City in China and other green architecture projects around the world, looking at how people are working together to change the urban landscape of the future.