Madrid, under EU warnings for its poor air quality, has come up with a bold plan to ring the capital with a greenbelt woven around the city's edges and over its highways to help absorb CO2 as well as provide new park land.
The plan, already named Bosque Metropolitano, or Metropolitan Forest, has €4.1 million in seed money to get the project kicked off, and a contest for concept design is underway. The total project is estimated at €75 million, of which the city already has €16 million on hand. Development time is estimated at about 12 years.
Although the city already has enough land in its two big parks, El Retiro and Casa de Campo to provide more than double the WHO recommendation of per capita park land, it isn't evenly distributed, and is in particularly short supply in the southern part of the city.
The new park lands, which will have up to 450,000 trees in its 600 hectares of land, will be planted in native species including holly oaks, pines and poplars. Where the green lands encounter highways, bridges will carry a greenway across, allowing wildlife to cross the road. When finished, the greenbelt will have the capacity to absorb 170,000 tonnes of CO2 each year.