Today, in our environmental science lecture, we'll discuss urban heat islands. This phenomenon occurs when cities are significantly warmer than surrounding rural areas. One key factor is the replacement of natural surfaces with concrete and asphalt, which absorb and retain heat. Another contributor is waste heat from vehicles and air conditioning units. To mitigate this, cities are increasingly adopting green roofs, which are covered with vegetation. These roofs not only reduce building temperatures but also improve air quality and manage stormwater runoff. However, their effectiveness depends on climate and building design. In our case study of Melbourne, we found that green roofs reduced surface temperatures by up to 4 degrees Celsius during summer. This data highlights the potential of such sustainable solutions.
❓ According to the lecture, what is a major cause of urban heat islands?
A. A. Lack of wind circulation in city centers
B. B. Replacement of natural surfaces with heat-absorbing materials
C. C. Excessive use of solar panels on buildings
D. D. Increased rainfall in urban areas
✅ 正确答案
B. Replacement of natural surfaces with heat-absorbing materials