Today in our environmental science lecture, we're discussing urban green spaces. A recent study in Melbourne found that adding more parks and trees in city centers can reduce local temperatures by up to 4 degrees Celsius during heatwaves. However, the researchers noted that the cooling effect is strongest within 100 meters of the green area. Beyond that distance, the benefit drops sharply. The study also highlighted that vertical gardens on buildings are less effective than ground-level parks for cooling, but they still help with air quality. So, while green roofs are useful, they don't replace the need for larger communal parks.