John-san and the tree climbers don't use spikes and their harness and ropes do not harm the tree in any way. John-san says that he can't go more than a few days without climbing into a tree. He makes it very clear why he is so passionate about this activity. Tree climbing is unique, it is a living world. Unlike a rock, it grows and changes every year.
Every tree is different, like a person's fingerprints.
It is the therapeutic properties of tree climbing that John-san promotes most often. Being in a wheelchair, she was used to people looking down at her. Almost everyone is taller when you are sitting down. This lady told John-san that people would even ignore her or choose to talk instead to the person pushing the chair. But in the tree she felt equal with everyone else.