Today, in our environmental science lecture, we're discussing urban green spaces. A recent study in Melbourne found that adding more parks and trees can reduce the city's average temperature by up to 2 degrees Celsius during summer. However, the researcher noted that the cooling effect is strongest within 400 meters of a green area, and it diminishes with distance. Interestingly, the study also showed that vertical gardens on buildings have a minimal impact compared to street-level trees. Therefore, city planners are now prioritizing the creation of small pocket parks in densely populated neighborhoods rather than large remote parks.