Going green: A tour of world cities putting down roots

Paris: From a New York rooftop, across Riyadh's desert cityscape or along the bustling streets of Medellin, to running the height of a Milan apartment block or stacked high in a Copenhagen farm, AFP has captured images of urban green replanting projects in cities around the world.

Singapore's futuristic garden: Gardens by the Bay, with its giant concrete trees covered in thick vegetation and huge greenhouses showcasing thousands of rare plant species, has grown into a source of pride and a symbol of the city-state.

A view inside the Cloud Forest at Gardens by the Bay in Singapore.

Farming on the New York skyline: Across three rooftops in New York, Brooklyn Grange grows more than 45 tonnes of organic produce a year in a city farm opened about a decade ago by a group of friends who wanted "a small sustainable farm that operated as a business", co-founder Gwen Schantz said.

People visit the Brooklyn Grange rooftop farming company and sustainability center during an open day, in the New York City borough of Brooklyn.

From living in Milan's vertical forest...: Two apartment buildings in the heart of Milan almost disappear under the lush forest of the Bosco Verticale (Vertical Forest), covered with more than 20,000 trees and plants from top to bottom, which aims to make trees an essential component of architecture.

The complex, designed by Studio Boperi, is located in the modern district of Porta Nuova in Milan.

A view from a balcony of the Vertical Forest high-rise complex.

...to vertical farming in Copenhagen: Although it may resemble a contemporary art installation, Copenhagen's vertical farm, opened by Danish start-up Nordic Harvest, grows the likes of kale and lettuces.

Harvested 15 times a year, produce is cultivated in tiered racks under 20,000 specialised LED lightbulbs that keep the massive warehouse in an industrial zone bathed in purple light around the clock.

A robot, used to plant seeds and check the plants while growing, moves past vertical racks at the vertical plant farm 'Nordic Harvest' based in Taastrup, a suburb west of Copenhagen.

Riyadh's reforestation: In the dust and desert heat, Riyadh's only greenery is almost lost between the busy highways and enormous interchanges.

But by 2030, 7.5 million trees - mostly acacias capable of withstanding the arid climate - and 3,000 urban parks are due to give the Saudi capital a green overhaul.

People walk on a tree-lined lane in the Saudi capital Riyadh.

Medellin's 'green corridors': Urban roads in Colombia's second-biggest city, Medellin, have been transformed into 30 "green corridors".

Where once the roadside was barren, worn down by the heat and rubbish-strewn, now trees and flowers luxuriantly fill them, in an interconnected network linked to existing green spaces.

A man walks near the vertical garden of a building at the Alpujarra sector in downtown Medellin, Colombia.

A jungle on Chengdu's balconies: With thick vegetation filling every apartment balcony for eight blocks, residents of China's experimental green housing project, Chengdu's Qiyi City Forest Garden, live in a vertical forest while in the middle of a megacity.

A view of the residential communities.

Residents resting on balconies covered with plants.