Today in our environmental science lecture, we're discussing urban green spaces. Recent studies show that city parks not only improve air quality but also significantly reduce the heat island effect. For example, a park in Manchester, UK, was found to lower local temperatures by up to 2 degrees Celsius during summer afternoons. However, researchers emphasize that the size and tree density of the park are crucial. Small gardens with scattered trees have minimal impact, while large, densely wooded areas create a noticeable cooling zone extending several hundred meters beyond their borders. This has implications for city planning, especially in densely built districts where land is limited.