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Listen to part of a lecture in an environmental science class. The professor is discussing the concept of 'urban heat islands.' Professor: Today, we're going to talk about urban heat islands, which are areas in cities that are significantly warmer than their rural surroundings. This happens because buildings, roads, and other infrastructure absorb and re-emit the sun's heat more than natural landscapes do. For example, asphalt and concrete have low albedo, meaning they reflect little sunlight and absorb a lot of heat. In contrast, vegetation, such as trees and grass, provides shade and releases moisture through evapotranspiration, which cools the air. So, cities often have higher temperatures, especially at night when the stored heat is slowly released. To mitigate this effect, some cities are implementing green roofs, planting more trees along streets, and using reflective materials on pavements. These strategies not only lower temperatures but also reduce energy consumption for air conditioning and improve air quality. However, these measures require careful planning and investment. So, the question is: how can we balance urban development with environmental sustainability?