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.
❓ What does the lecturer say about green roofs?
A. They are more effective than reflective paints for reducing city temperatures.
B. They can significantly lower rooftop temperatures but have limited city-wide impact.
C. They are the most cost-effective method for large buildings.
D. They reduce energy consumption by 10 to 15 percent.
✅ 正确答案
They can significantly lower rooftop temperatures but have limited city-wide impact.