Colombia’s second largest city, Medellín, is adapting to climate change and giving residents a better quality of life by creating green corridors, areas thick with vegetation, along 18 roads and 12 waterways.
The urban greening programme, known as Green Corridors, is increasing biodiversity and reducing heat stress in the city. Cooling is created by more shading, cuts to the heat radiated by solid surfaces such as a roads, and water evaporating from plants.
Medellín, like many other cities, faces rising temperatures, worsened by the urban heat island effect – concrete and tarmac absorbing the sun’s power, radiating it out as heat and keeping the city warm long after the sun has gone down.
Medellín’s mayoral team, who devised the Green Corridors programme, identified an interconnected network of greenery across the city’s connecting streams, hills, parks, and roads as areas where to plant trees, shrubs, palms and green cover.
The initiative adds to and further connects existing green spaces, improves urban biodiversity, reduces the city’s urban heat island effect, soaks up busy streets’ air pollutants, and sequesters a significant amount of CO2 thanks to vigorous new vegetation growth.
Each corridor is designed specifically to mimic a natural forest situation. This means there are low, medium and high plants to encourage animals and insects. Taller trees have been planted that will, when fully grown, provide the maximum amount of shading and cooling.
Among the programme’s highlights include Oriental Avenue, a main road in which 2.3km of paving was replaced by gardens. La Hueso Green Corridor, a once underused area under the above-ground Metro line, is now home to a site where rainwater is collected from the bridge, filtering it down through a system of pipes to water the greenery which includes ‘green walls’ planted with vegetation. This green corridor helps to reduce the temperature along a popular cycling route.
Since the programme started in 2016, the botanical gardens have trained 75 new gardeners. This has helped people who are most vulnerable, displaced by the armed conflict or from poorer rural communities to find work. The apprenticeship scheme gives them workplace training as well as a qualification.
Trees and shrubs have reduced the surface temperature in Medellin by 2-3 ̊C and have also improved air quality and biodiversity.
The Green Corridors project demonstrates how integrated, nature-based policies like widespread urban tree planting can have a far-reaching impact on the local and global environment, as well as significantly improving citizens’ lives and well-being.
Rosa Medea is Life & Soul Magazine’s Chief. She writes about lifestyles including sustainable and green living. She also offers content services to businesses and individuals at Rosamedea.com