Today in our environmental science lecture, we're discussing urban green spaces. A recent study in Melbourne found that parks can reduce local temperatures by up to 4 degrees Celsius during heatwaves. However, the effect depends on the size and density of trees. Small gardens with scattered shrubs have minimal impact, while large, connected parklands create cooling corridors. Interestingly, the study also noted that water features, such as ponds, enhance the cooling effect, but they require significant maintenance. So, for city planners, the key is to prioritize larger, interconnected green areas over many small ones.