Today in our environmental science lecture, we'll discuss urban green spaces. A recent study in Melbourne found that adding parks and community gardens to city centers can reduce local temperatures by up to 3 degrees Celsius during summer heatwaves. Interestingly, the cooling effect is strongest within 200 meters of the green area, and it also improves air quality by filtering particulate matter. However, the researchers noted that the benefits depend on regular maintenance, especially watering trees during dry periods. So, while green infrastructure is valuable, it requires ongoing investment from city councils.