Today, in our environmental science lecture, we'll discuss the impact of urban green spaces. A recent study in Melbourne found that parks can reduce local temperatures by up to 4 degrees Celsius during heatwaves. Interestingly, the cooling effect is strongest within 100 meters of the park boundary. However, the size of the park matters less than the density of trees. For instance, a small park with mature trees outperforms a larger grassy area. The study also noted that water features, like ponds, do not significantly enhance cooling unless combined with shade. Therefore, city planners should prioritize tree planting over other interventions.