Author Richard Louv introduced the term “Nature-Deficit Disorder” in 2005 with the publication of his best-selling book, “Last Child in the Woods: Saving Our Children from Nature-Deficit Disorder.” He coined the phrase to serve as a description of the human costs of alienation from nature.  An expanding body of scientific evidence suggests that nature-deficit disorder contributes to a diminished use of the senses, attention difficulties, conditions of obesity, and higher rates of emotional and physical illnesses. Research also suggests that the nature-deficit weakens ecological literacy and stewardship of the natural world. These problems are linked more broadly to what health care experts call the “epidemic of inactivity,” and to a devaluing of independent play.