Green streets

1 Vertical forests in Milan

In Milan’s central business district, two plant-covered skyscrapers provide the same amount of vegetation as 30,000 sq metres of woodland, according to the project’s architect, Stefano Boeri. The Bosco Verticale complex comprises two towers, 800 trees, 15,000 ground-cover plants and 5,000 shrubs, which sit in tubs on large overhanging balconies. Ecologists carefully selected the plants, which attract 1,600 species of bird and butterfly, according to Boeri. The towers opened in 2014 and vegetation is trimmed so it doesn’t obstruct the view. The architect has since created designs to build Forest City in Liuzhou, China.

2 Wildlife bridges in Edmonton

More than a dozen wildlife bridges and passages have been built in