TOEFL Listening

🎧 Listening Transcript

Listen to part of a lecture in an environmental science class. The professor is discussing urban heat islands. "Urban areas tend to be warmer than surrounding rural areas, a phenomenon known as the urban heat island effect. This occurs because concrete, asphalt, and buildings absorb and re-radiate heat more than natural landscapes like soil and vegetation. Additionally, waste heat from vehicles, air conditioners, and industrial processes adds to the warmth. The lack of trees and green spaces reduces shade and evapotranspiration, which normally cool the air. As a result, cities can be several degrees hotter than nearby countryside, especially at night when the stored heat is released slowly. This effect has significant consequences, including increased energy demand for cooling, higher air pollution levels, and greater heat-related health risks. To mitigate this, some cities are implementing green roofs, planting more trees, and using reflective materials on pavements and buildings. These strategies not only lower temperatures but also improve air quality and reduce stormwater runoff. However, such measures require careful planning and investment, and their effectiveness varies with local climate and urban design."