Today in our environmental science lecture, we're discussing urban green spaces. A recent study in Melbourne found that adding more parks and tree-lined streets can reduce city temperatures by up to 4 degrees Celsius. However, the key is not just the number of trees but their placement. Shading buildings and pavements directly has the greatest cooling effect. Interestingly, the study also noted that green roofs on high-rise buildings were less effective for street-level cooling than ground-level parks. So, while vertical greening is popular, for maximum benefit, we should prioritize ground-level interventions in densely built areas.