Today in our environmental science lecture, we'll discuss urban green spaces. A recent study in Melbourne found that adding more parks and community gardens can reduce the city's average temperature by up to two degrees Celsius during summer heatwaves. This is because plants provide shade and release moisture through transpiration. However, the researchers noted that the benefits are only significant if green spaces cover at least 30% of a neighborhood's area. Smaller, scattered gardens have minimal cooling effects. The study also highlighted that trees along streets are more effective than grass areas alone, as they block direct sunlight and create wind corridors.