7 ways towns and cities are turning from grey to green

Urbanization is a fact of modern life, but that doesn’t necessarily mean city dwellers are abandoning nature.

The UN predicts two-thirds of the world’s population will be living in cities by 2050. As people come to terms with the dramatic increase in urbanized areas and the corresponding loss of wildlife, there is a growing focus on how to improve urban biodiversity.

While the move towards urbanization cannot be reversed, many cities are finding ways to improve the quality of city life and actively bring wildlife back into cities.

These are seven stand-out examples of how cities are learning to nurture plants and wildlife.

1.The UK’s wildlife-friendly housing development

An £81m ($107m) housing development in southeast England, which includes 2,450 new homes, is deliberately courting more wildlife.

The bird charity the RSPB has created “swift bricks”, which allow birds to roost without causing damage.

Housing for bats, sparrows and house martins are also being built into the structure of the new homes, while wildlife corridors of hedges and patches of wildflowers aim to attract bees, hedgehogs and insects.

2. China’s ‘Forest City’

The Chinese government is building a new city where all the buildings – including schools, offices, homes and hospitals – will be covered in over 40,000 trees and 1 million plants. The Forest City is in the mountainous region of Guangxi in southern China and is due to be completed by 2020.

China is battling poor air quality, and one of the key ambitions of the Forest City is to soak up carbon dioxide in the atmosphere and help reduce air pollution.

3. Italy’s library of trees

A new library in the heart of Milan’s grey business district will be full of trees and plants rather than books. In total there will be 450 trees from 19 species, plus 90,000 plants including hedges, shrubs and climbers. When completed in 2018, the Biblioteca degli Alberi will be a 3,500m2 green space in the heart of the city.

4. The USA’s urban tree canopy

Baltimore is on a mission to plant enough trees to achieve its goal of 40% urban tree canopy. Tree planting is happening in neighbourhoods with few existing trees and 4,000 new trees have been planted since the scheme began.

Officials have now stipulated that half of the canopy trees should be oaks, thanks to the way that oaks benefit everything from caterpillars to songbirds. Even fish prosper, as the aquatic invertebrates they eat favour oak leaves on the bottom of streams.

5. Australia’s 100m high vertical garden

The $1.5bn development called One Central Park in Sydney is designed to improve the quality of high-rise living through greenery and redirected sunshine. The towers are covered in plants but also reflect light in their lower levels with a huge cantilevered panel of mirrors.

6. France’s factory conversion

A former Renault factory in the northern French city of Boulogne has become a school specially designed to encourage flora and fauna. The building has a green roof that is allowed to slope down so that it extends to every level of the school.

The extra green space not only creates a healthy environment for children in the city, but also allows students to experience a real-life ecosystem.

7. Canada’s green roofs

Toronto was the first city in North America to pass a bylaw requiring commercial, institutional and residential developments over a certain size to install green roofs.

A green roof includes a root repellent system, a drainage system, and plants growing on a waterproof membrane. The green roof scheme has since been found to help prevent flooding, as well as creating a habitat for birds and other creatures.