Comprensión auditiva TOEFL

🎧 Transcripción de audio

Narrator: Listen to part of a lecture in an environmental science class. Professor: Today we're going to talk about a surprising solution to urban heat islands—that's when cities are significantly warmer than surrounding rural areas. One common approach is planting trees, which provide shade and release moisture. But there's another, less obvious factor: the color of rooftops. Dark roofs absorb heat, raising building temperatures and increasing air-conditioning costs. Some cities, like Los Angeles, have started programs to coat rooftops with reflective white paint. This 'cool roof' technology can lower a roof's surface temperature by up to 50 degrees Fahrenheit on a hot day. That reduction not only cuts energy use but also reduces the overall city temperature, because less heat is radiated back into the air. However, cool roofs aren't a perfect solution. In colder climates, they might increase heating costs in winter by reflecting away beneficial solar warmth. Also, the reflective coating can degrade over time, requiring maintenance. Still, for many regions, cool roofs offer a low-cost, immediate way to combat rising temperatures.