Today in our environmental science lecture, we'll discuss urban heat islands. These occur when cities are significantly warmer than surrounding rural areas. One major cause is the replacement of natural surfaces with asphalt and concrete, which absorb and retain heat. Another factor is the lack of vegetation, as trees provide shade and release moisture through transpiration. Interestingly, studies show that the temperature difference can be as high as 10 degrees Celsius on clear, calm nights. To mitigate this effect, cities are implementing green roofs and increasing tree canopy. However, these solutions require substantial investment and long-term planning. Now, let's examine a case study from Melbourne, where they've seen a 4-degree reduction in peak summer temperatures after planting over 70,000 trees.
❓ Según la conferencia, ¿qué se menciona como una causa principal de las islas de calor urbanas?
A. A. Falta de viento en las áreas urbanas
B. B. Reemplazo de superficies naturales con materiales como asfalto y concreto
C. C. Altos niveles de contaminación por vehículos
D. D. Uso excesivo del aire acondicionado en los edificios
✅ 正确答案
B. Replacement of natural surfaces with materials like asphalt and concrete