When I first found the second-floor flat in San Francisco that I’ve called home for the past 25 years, I was thrilled that it had a backyard and that I could see neighboring yards with trees and gardens as well as distant green hills from my back windows. I didn’t know then that scientists had begun investigating the benefits of nature and greenery to the human body and psyche. I just knew that looking out on or being in my backyard fed my soul.More recently, when a Chinese Massage (Chi Nei Tsang) therapist found my liver was tight and congested, she recommended a daily practice of looking at something living and green—as close as possible to the color of new grass—with my palm over my liver, and visualizing inhaling the color into my liver to soothe and heal it. Was it just my imagination or could I actually feel the color filling my liver, releasing and revitalizing it?As the world’s population has exploded, cramming more and more of us into crowded cities, we’re getting less and les…