TOEFL Listening

🎧 Listening Transcript

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. The main cause is the replacement of natural surfaces with materials like concrete and asphalt, which absorb and retain heat. Additionally, waste heat from vehicles, air conditioners, and industrial processes contributes to the effect. But there are solutions. One effective strategy is increasing urban greenery, such as planting trees on streets and creating parks. Trees provide shade and release moisture through evapotranspiration, which cools the air. Another approach is using cool roofs, which are designed to reflect more sunlight and absorb less heat than standard dark roofs. These roofs can be painted with reflective coatings or made from special materials. Some cities have also implemented green roofs, which are covered with vegetation, providing insulation and reducing stormwater runoff. While these measures require initial investment, they can lower energy costs for cooling and improve public health by reducing heat-related illnesses.