Today in our environmental science lecture, we'll discuss urban heat islands. As cities grow, concrete and asphalt replace natural surfaces, absorbing more sunlight and releasing heat at night. This makes cities warmer than surrounding rural areas. One surprising factor is the lack of vegetation. Trees provide shade and release moisture through transpiration, which cools the air. In a recent study of a mid-sized city, researchers found that adding green roofs to 20% of buildings could reduce peak summer temperatures by up to 2 degrees Celsius. However, the effect varies with building height and wind patterns. So, while green infrastructure helps, it's not a complete solution.
❓ According to the lecture, what did the recent study find about adding green roofs?
A. A. They have no significant impact on urban temperatures.
B. B. They can reduce peak summer temperatures by up to 2 degrees Celsius if applied to 20% of buildings.
C. C. They are only effective in cities with tall buildings.
D. D. They increase humidity and make cities feel warmer.
✅ 正确答案
B. They can reduce peak summer temperatures by up to 2 degrees Celsius if applied to 20% of buildings.