TOEFL Listening

🎧 Listening Transcript

Listen to part of a lecture in an environmental science class. The professor is discussing the concept of urban heat islands. "Now, urban areas tend to be warmer than the surrounding rural areas. This is known as the urban heat island effect. Why does this happen? Well, there are several factors. First, buildings and roads made of concrete and asphalt absorb a lot of solar energy during the day and release it slowly at night. In contrast, vegetation, like trees and grass, provides shade and releases moisture through a process called evapotranspiration, which cools the air. Second, the lack of vegetation in cities reduces natural cooling. Third, human activities, such as driving cars and running air conditioning, generate waste heat. All these contribute to higher temperatures in cities. Interestingly, the temperature difference is often greater at night and in winter. This effect has significant implications for energy consumption and public health, especially during heat waves. Some cities are implementing green roofs and planting more trees to mitigate this problem."