Today in our environmental science lecture, we'll discuss urban heat islands. Cities tend to be warmer than surrounding rural areas due to concrete and asphalt absorbing sunlight. One surprising factor is that green roofs, which are covered with plants, can reduce rooftop temperatures by up to 30 degrees Celsius. However, their overall effect on city-wide cooling is limited because they cover only a small fraction of building surfaces. Another method, using reflective paints on roofs, has been shown to lower energy consumption for cooling by 10 to 15 percent. While both approaches are beneficial, reflective paints are more cost-effective for large-scale application.
❓ 讲师对绿色屋顶有何看法？
A. 它们比反射涂料更能有效降低城市温度。
B. 它们能显著降低屋顶温度，但对整个城市的影响有限。
C. 对于大型建筑而言，它们是最具成本效益的方法。
D. 它们将能源消耗降低了10%至15%。
✅ 正确答案
They can significantly lower rooftop temperatures but have limited city-wide impact.