Today's children are living a childhood of firsts. They are the first daycare generation; the first truly multicultural generation; the first generation to grow up in the electronic bubble, the environment defined by computers and new forms of television; the first post-sexual revolution generation; the first generation for which nature is more abstraction than reality; the first generation to grow up in new kinds of dispersed, deconcentrated cities, not quite urban, rural, or suburban.

Nature-deficit disorder describes the human costs of alienation from nature, among them: diminished use of the senses, attention difficulties, and higher rates of physical and emotional illnesses. The disorder can be detected in individuals, families, and communities.

What if more and more parents, grandparents and kids around the country band together to create outdoor adventure clubs, family nature networks, family outdoor clubs, or green gyms? What if this approach becomes the norm in every community?

From 1997 to 2003, there was a decline of 50 percent in the proportion of children nine to twelve who spent time in such outside activities as hiking, walking, fishing, beach play, and gardening, according to a study by Sandra Hofferth at the University of Maryland.

Time in nature is not leisure time; it's an essential investment in our chidlren's health (and also, by the way, in our own).

We cannot protect something we do not love, we cannot love what we do not know, and we cannot know what we do not see. Or hear. Or sense.

Natural playgrounds may decrease bullying.