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, cities tend to be warmer than the surrounding rural areas. This is known as the urban heat island effect. There are several reasons for this. First, buildings and roads made of concrete and asphalt absorb and re-emit more solar radiation than natural landscapes like vegetation and soil. Second, these materials also have lower albedo, meaning they reflect less sunlight and absorb more heat. Third, human activities, such as driving cars and running air conditioners, generate waste heat. Interestingly, the temperature difference between a city and its outskirts is often most pronounced at night. During the day, buildings store heat, and at night, they slowly release it, preventing the city from cooling down as quickly as rural areas do. One potential solution is to increase green spaces, like parks and green roofs, which can provide shade and cool the air through evapotranspiration. Another is to use reflective materials on rooftops and pavements to reduce heat absorption."