24/07/2026
前几天在路边
看见好几棵大大的树被砍伐了
心里真感到痛心
无知的人类为了让道路更宽敞
容得下更多破环环境的工具
而牺牲了默默为我们付出的大树
是不是要等到那股“热”
能热死人了
才后悔自己过度开发呢？
A city can cool itself when it makes room for trees, water, and living systems.
Medellín, Colombia, once struggled with intense urban heat linked to dense development, reduced green space, air pollution, and the urban heat island effect. Through its “Green Corridors” project, the city transformed roadsides, riverbanks, parks, and public transport routes into connected networks of vegetation.
According to the World Economic Forum, Medellín planted about 2.5 million plants and 880,000 trees. The project cost about $16.3 million to install and around $625,000 per year to maintain. The city has reported an average temperature reduction of about 2°C, or 3.6°F.
The cooling comes from processes long understood through land-based knowledge as well as modern urban science. Trees create shade, keeping asphalt, concrete, sidewalks, and buildings from absorbing as much heat. Plants also cool the surrounding air through evapotranspiration, as water evaporates from leaves and draws heat from the environment.
Urban forests can also help trap particulate pollution, absorb carbon dioxide, reduce stormwater runoff, provide habitat for birds and other wildlife, and make neighborhoods more walkable.
For many Indigenous communities, healthy cities and healthy lands are not separate conversations. The same principles that guide care for forests, waterways, and plant relatives can also shape how urban spaces respond to climate change and extreme heat.
Medellín is now being studied by planners in other cities looking at nature-based approaches such as tree planting, green roofs, restored waterways, and expanded parks.
Source: World Economic Forum
What kinds of green spaces would make the biggest difference in your community?
