The air that wraps Earth is a single entity, the matrix that holds us all. It is a global commons from which we draw a crucial element of life, sharing as we do molecules that have been breathed in and out of every living thing that has ever breathed on Earth. Molecules that pass through us have passed through brontosaurs, neolithic hunters, Roman emperors, hummingbirds, snails.

~ David Suzuki, The Sacred Balance: Rediscovering Our Place in Nature

Twilight Moon, Canyonlands National Park, UT – photo by Gary Hart Photography, used with permission