Today in our environmental science lecture, we'll discuss urban heat islands. These are areas in cities that are significantly warmer than surrounding rural areas. The main cause is the replacement of natural surfaces with concrete and asphalt, which absorb and retain heat. Additionally, lack of vegetation reduces shade and evapotranspiration. A key study in Phoenix, Arizona, found that installing reflective roofs on buildings could lower city temperatures by up to 2 degrees Celsius. However, researchers noted that planting more trees in residential neighborhoods had a greater effect on reducing nighttime heat, because trees release moisture and block longwave radiation. This is why many city planners now prioritize green spaces over reflective surfaces.
❓ Según la conferencia, ¿qué descubrió el estudio en Phoenix sobre la reducción del calor urbano?
A. A. Los techos reflectantes fueron más efectivos que los árboles para reducir las temperaturas nocturnas.
B. B. Plantar árboles en áreas residenciales redujo el calor nocturno más que los techos reflectantes.
C. C. El hormigón y el asfalto absorben menos calor que las superficies naturales.
D. D. Las islas de calor urbanas solo ocurren durante el día.
✅ 正确答案
B. Planting trees in residential areas reduced nighttime heat more than reflective roofs.