1. Temperature control 2. Noise reduction 3. Increased oxygen and air purity 4. Aesthetics 5. Reduced light pollution 6. Reduced flood risk 7. Increased psychological and physical health of residents (scientifically proven) 8. Increased privacy 9. Supporting wildlife 10. They are carbon sinks. Remind me again why we are not planting more trees just about everywhere that we can? ... my idea is that we do. Reason 11: incentives to get residents helping with planting seedlings is a great way to establish a sense of community. Credit for this idea to Greenlife (smiley face).