“All you have to do is climb a tall building in Germany, and you’re going to see green roofs all over the place.”

Many countries like Germany (pictured) and Switzerland are now mandating that all new buildings with flat roofs must plant a garden on them. What will cities look like when this practice becomes the norm? (Pics)

Here you can see a Chicago rooftop, whose green garden looks like a luxury rather than something that’s been mandated.

Inspired by a worldwide movement, Mayor Richard Daley has made Chicago North America’s leading “green roofs” city.

And then there are buildings like this one in Vancouver, which goes beyond roof greening to turn every single wall into a garden too.

The Vancouver Aquarium’s Living Wall

Imagine entire cities with skyscrapers that look like this. It’s possible that one of the best ways to create energy efficient cities will be to create buildings like these, where plant life helps to regulate the structure’s temperature. Rooftop and wall gardens could also become farms.

Tokyo’s historic Imperial Hotel combines rooftop plants with solar electric panels that mimic the shape of a garden pond.

In Tokyo, where the “urban heat island” phenomenon has raised local temperatures by several degrees, city officials are mandating green roofs like this one to make buildings more efficient and bring temperatures down. Heat islands are caused when cities have so much asphalt and cement that they absorb and trap heat. Environmental planners hope that green rooftops will cool the city off.

Via io9