Today, in our environmental science lecture, we're discussing urban green spaces. A recent study in Melbourne found that parks can reduce surrounding temperatures by up to four degrees Celsius during heatwaves. This cooling effect extends about 100 meters from the park boundary. Interestingly, the presence of water features, like ponds, enhances this effect significantly. However, the study also noted that tree density matters more than the total park size. For example, a small park with dense trees can be more effective than a large open lawn. So, when planning new residential areas, city planners should prioritize planting clusters of trees rather than just creating large grassy areas.