One person can make a difference -- purchase your copy of For America and discover simple ways to improve your life, your country, even the world. A simple and attractive way to cut energy costs, reduce power-plant emissions, improve air quality, and ensure public health.
Each time a city building is erected, the grass in that spot and trees that once reached up to the sky are replaced by a swath of asphalt1 or a tar roof.
Add to that the construction of roads, parking lots, and yet more buildings, and the total lost green space can have a very real effect on a city's air temperature, air quality, and energy costs. On a summer day in most American cities, a tar roof can feel like the inside of an oven. But what if we could replace the hot roof of each skyscraper or building in a city with grass or a garden?
Whether it holds vegetable gardens, wildflowers, or meadow grasses, a green roof can lower the temperature above a building by 60 degrees, which can reduce the building's energy costs and, if used more widely, could decrease a city's total energy costs, reduce power-plant emissions, and improve air quality and public health.
But that's not all -- green roofs are a great way to handle water management in urban areas with overwhelmed sewerage systems (green roofs soak up excess precipitation2)), provide sanctuaries 3 for urban wildlife, and actually extend the life span of the roof itself. And green roofs do something else: They beautify the city -- whether you're on the 3rd floor or the 30th. Now that's a crowning4 achievement.
1．asphalt n. 沥青,柏油
2. precipitation n. 降水量
3. sanctuaries n. 鸟兽保护区
4. crowning adj. 使完美圆满的