Today, in our environmental science lecture, we're discussing urban green spaces. A recent study in Melbourne found that parks and community gardens can reduce local temperatures by up to 4 degrees Celsius during heatwaves. The researchers also noted that trees are more effective than grass at cooling, mainly because they provide shade and release moisture. However, the study emphasized that the location of green spaces matters. For example, small parks scattered throughout the city are more beneficial than one large park, as they ensure cooler areas are accessible to more residents. Interestingly, the cooling effect was strongest within 100 meters of the green space.