In “Garbology: Our Dirty Love Affair With Trash,’’ Edward Humes reminds us of something we try to forget: We are a wasteful society with a trash problem that is polluting our oceans and packing our landfills. Humes examines the scale of the problem. He then picks through our refuse to see what our garbage reveals about our culture and its values. He ends with positive examples and reasonable alternatives to help every person to make even a small difference.