In central Phoenix, rows of multidecadal Aleppo pines and evergreens form lush corridors along residential city streets. Their canopies expand over roadways and sidewalks, diverting the Phoenix sun, allowing for a thriving ecosystem of human activity to form within its cover. Couples walk on sidewalks pushing strollers, a teenager rides his bike in the designated lane and an elderly man tends to a flowering rose bush in his front yard.

About seven miles away, a South Phoenix neighborhood built alongside a freeway bakes in the sun, its asphalt exposed from sunrise to sunset with limited tree cover across the residential area.