Trees are vital for cooler cities, but they need help too

This summer, walking beneath trees felt like autumn had already arrived with dry, dead leaves crunching and crowns tinged yellow or bare. These large leafy trees provide many benefits to cities, including blocking sunlight, reducing pollution, storing carbon, providing habitats for biodiversity, soaking up stormwater runoff, and improving the mental and physical health of residents.

However, as humans burn fossil fuels, the planet has become hotter, making urban trees more vital. Trees act like giant air conditioners, with temperatures up to three degrees cooler inside their canopy than the surrounding area due to evapotranspiration. Additionally, trees provide shade, keeping their surroundings from heating up.

Studies have shown that cities with more tree canopy have lower rates of cardiovascular disease, better grades in high schools, and healthier outcomes for newborns. To thrive, trees need significant amounts of water, but protecting older, struggling trees should be a priority over planting new, less water-hungry ones. Mature trees provide exponential benefits, but it takes time and maintenance.

Watering techniques, such as using irrigation bags or gravel in the soil, can help ensure trees receive sufficient water without damaging their roots. When selecting trees for urban areas, diversity is crucial to adapt to changing climates and resist threats like pests or disease.