Today in our environmental science lecture, we're discussing urban green spaces. A recent study in Melbourne found that parks reduce local temperatures by up to 4 degrees Celsius during heatwaves. However, the benefit depends on tree canopy coverage. Areas with less than 30% canopy showed minimal cooling. Interestingly, the study also noted that the presence of water features, like ponds, had a stronger effect than grass alone. But the most surprising finding was that small, scattered gardens in residential streets were more effective at lowering nighttime temperatures than a single large park. This is because they provide continuous shade and moisture throughout the city.