Today in our environmental science lecture, we'll discuss urban green spaces. A recent study in Melbourne found that parks can reduce surrounding temperatures by up to 4 degrees Celsius during heatwaves. However, the cooling effect diminishes significantly beyond 100 meters from the park boundary. Interestingly, the study also showed that trees are more effective than grass at cooling, because they provide shade and release moisture through transpiration. The researchers recommend planting a mix of native and non-native species, but emphasize that native trees require less water and support local biodiversity. So, when designing new parks, city planners should prioritize native canopy trees over ornamental lawns.