Problem

Traditional urban planning frameworks overlook green infrastructure, which has led to a proliferation in many urban areas globally of inaccessible parks and lack of shaded streets. In tropical cities such as Medellín, Colombia this drives a dual pressure of urban heat islands and air pollution — dense urbanisation, paved surfaces, and vehicular emissions elevate ambient temperatures and particulate matter.

This impacts public health, especially among low-income and outdoor workers, with extreme heat also contributing to respiratory, cardiovascular issues, and reduced quality of life. Without coordinated interventions, vulnerable populations, such as slum dwellers, informal street vendors, and students, remain disproportionately affected by climate stressors.

Response

Since 2016, Medellín has implemented the Green Corridors (Corredores Verdes) initiative across key urban pathways, including pedestrian routes, stream sides, and hillside belts. These corridors feature native trees, bushes, and shaded pathways, designed to lower land surface temperatures (by up to 2.7 °C), filter air pollutants, and reduce runoff. The initiative is a collaboration between Medellín’s Municipality, local universities, NGOs, urban planners, and community groups. Green jobs are created for local residents trained in planting, corridor maintenance, and environmental monitoring. Universities conduct air and temperature monitoring and feed data into planning. 

The corridors are co-managed by community-based organisations, ensuring responsiveness to safety, cultural use, and public access needs. Schools, workplaces, and neighbourhood networks are engaged through co-design workshops that align routing with daily urban life. In addition to cooling, the corridors serve to slow surface runoff and enhance biodiversity, with multiple studies validating their social, environmental, and economic impacts. The city embeds these corridors within broader climate resilience and mobility plans, prioritising equitable access to green infrastructure across socio-economic zones.

Find Out More: WWF, Alcadía de Medellín