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, I want to talk about urban heat islands and why they matter. As you know, cities tend to be warmer than the surrounding rural areas. This phenomenon is called the urban heat island effect. But what causes it? Well, there are several factors. First, concrete and asphalt absorb and retain heat during the day and release it slowly at night, keeping temperatures higher. Second, buildings block wind, reducing natural cooling. Third, there's less vegetation in cities, which means less shade and less evapotranspiration—that's the process where plants release water vapor and cool the air. So, what can we do about it? One solution is to plant more trees and create green roofs. Green roofs are covered with vegetation and soil, which can significantly lower rooftop temperatures. Another approach is to use reflective materials for roads and buildings, which bounce sunlight back instead of absorbing it. These measures not only reduce heat but also lower energy consumption for air conditioning, which is a major contributor to greenhouse gas emissions. So, addressing urban heat islands isn't just about comfort—it's a climate mitigation strategy."