Today in our environmental science lecture, we'll discuss urban green spaces. Recent studies show that parks in cities can reduce the local temperature by up to 2 degrees Celsius during summer. This cooling effect is mainly due to shade from trees and water evaporation from plants. Additionally, green spaces improve air quality by absorbing pollutants like carbon dioxide and nitrogen dioxide. However, the location of parks matters. For maximum benefit, they should be evenly distributed across the city, not just in wealthy areas. Interestingly, smaller parks scattered throughout neighborhoods are more effective for residents' mental health than one large central park, as they encourage more frequent visits.