Today, in our environmental science lecture, we will discuss the impact of urban heat islands. A recent study in Melbourne found that planting more trees in city centers can reduce surface temperatures by up to 4 degrees Celsius during summer afternoons. However, the effect is less significant at night, when heat stored in buildings and roads is slowly released. The study also highlighted that green roofs, though more expensive to install, provide better insulation in winter than street trees. Interestingly, the researchers noted that light-colored pavements reflect more sunlight than dark ones, but they do not cool the air as effectively as trees do.