托福听力

🎧 听力原文

Narrator: Listen to part of a lecture in an environmental science class. Professor: Today we're going to talk about urban heat islands, a phenomenon where cities are significantly warmer than surrounding rural areas. This happens because concrete, asphalt, and buildings absorb and re-emit heat from the sun more than natural landscapes do. Also, human activities like driving cars and running air conditioners generate additional heat. Now, one surprising effect of urban heat islands is their impact on precipitation. Warmer air can hold more moisture, so cities often experience more frequent and intense rainstorms. This can lead to flooding, especially since urban surfaces are largely impermeable, meaning water can't easily soak into the ground. To mitigate these effects, some cities are implementing green roofs and increasing tree cover. These measures not only cool the air but also absorb rainwater. So, while urban heat islands pose challenges, they also inspire creative solutions.