Today, in our environmental science lecture, we'll discuss urban heat islands. This phenomenon occurs when cities become significantly warmer than surrounding rural areas. The primary cause is the replacement of natural land cover with materials like concrete and asphalt, which absorb and retain heat. Additionally, waste heat from vehicles and air conditioning units contributes. Interestingly, parks and green roofs can mitigate this effect by providing shade and releasing moisture. A recent study in Melbourne showed that increasing tree canopy by 10% could lower city temperatures by up to 2 degrees Celsius during summer. So, urban planning must prioritize green infrastructure.
❓ According to the lecture, what is the main cause of urban heat islands?
A. A. Waste heat from vehicles and air conditioning
B. B. Replacement of natural land cover with heat-absorbing materials
C. C. Lack of wind in city areas
D. D. Increased sunlight reflection from buildings
✅ 正确答案
B. Replacement of natural land cover with heat-absorbing materials