In major cities, the problem of air pollution is one which is quickly reaching critical mass. While public transportation is being utilized as much as possible, along with more fuel efficient cars, in London, one university is studying the concept of living walls. On buildings all over London, researchers from Middlesex University have installed climbing plants. Different kinds of plants not only contribute to the look of a city, bringing lush green into urban areas, but they produce oxygen as well. The plants on building walls in London can absorb some of the fine particulate matter in the air as well, keeping pollutants from being inhaled by residents.
Walls are not the only places where greenery is being added. Some 200,000 square meters of rooftops have gardens planted on them. London isn't the only city adding plants to their architecture. In Milan, there are skyscrapers that have plants from top to bottom, integrated into the design and these buildings have won awards for design and for their environmental impact. With land at a premium in crowded cities, the only way to go is up!