GREEN ROOFS + WALLS
What’s all the fuss about green roofs? These roofs can be a modest planting, sometime of a single species. Sedums are very resistant, can live on very little water and very shallow soil. This modest planting can create a microclimate. Microclimates are the ecological movement’s next frontier. The evapotranspiration from these plants lowers the ambient temperature on this roof resulting in a cooler place, requiring less air conditioning. Furthermore the water from rain is absorbed by the plants and returned to the atmosphere or filtered through the soil, delaying it entry into the drainage system, lessening peak storm loads.
These green roofs can play the role of fifth facades in high rise cities like New York. Where people look down from above at other’s rooftops, green roofs become an aesthetic asset. Let’s add to that, that it triples the lifespan of a roof; and that it traps air-borne pollutants, producing oxygen.
The big picture is that half of the world lives in cities; it will be 2/3 by 2025. Cities are major producers of all the things which are feeding climate change. Green roofs are a simple tool we could use to change this effect, if used at the macroscale. Green roofs can also play the urban role of open space and social connectors.