Today, in our environmental science lecture, we'll discuss urban heat islands. Cities tend to be warmer than surrounding rural areas because concrete and asphalt absorb and re-radiate heat. However, one effective mitigation strategy is increasing green spaces, such as parks and green roofs. A recent study in Melbourne showed that adding trees along streets could reduce local temperatures by up to 2 degrees Celsius. Interestingly, the study also found that painting roofs white had a smaller effect, only about 0.5 degrees. Therefore, the most cost-effective solution for city planners is to prioritize tree planting in residential areas.