Today in our environmental science lecture, we'll discuss 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 cooling effect depends on the size and vegetation density. Small gardens with scattered trees have minimal impact, while large connected parks with dense canopy cover create a significant cooling corridor. The study also noted that water features, like ponds, enhance this effect but require careful maintenance to avoid mosquito breeding. Interestingly, the researchers suggested that even vertical gardens on building walls can lower indoor temperatures by 2 degrees, reducing air conditioning use by 10% in summer.