Today in our environmental science lecture, we'll discuss urban heat islands. As cities grow, concrete and asphalt absorb sunlight and re-radiate heat, making urban areas warmer than surrounding rural regions. A key solution is increasing green spaces, like parks and green roofs, which cool the air through evaporation and shade. However, the effectiveness depends on local climate. For instance, in dry regions, water for irrigation might be scarce, limiting the cooling benefit. In contrast, cities with ample rainfall can support lush vegetation, significantly reducing peak temperatures. Therefore, planners must consider regional water availability before implementing green infrastructure.