Shade Will Make or Break American Cities

On a 92-degree Saturday afternoon in Portland, Oregon, I went looking for shade in Cully Park, which was built on top of an old landfill and opened in 2018. The city included plenty of trees in the design—I mean, this is Oregon. But those trees are still slender saplings, each throwing enough shade for maybe a chihuahua. So the park’s designers also included two large metal canopies that protect a seating area from both winter drizzle and the summer scorchers that are becoming routine here. The tables were full of...