Now, my tree-climbing days long behind me, I often think about the lasting value of those early, deliciously idle days. I have come to appreciate the long view afforded by those treetops. The woods were my Ritalin. Nature calmed me, focused me, and yet excited my senses.

Kids and adults pay a price for too much tech, and it's not wholesale.

Each of us-adult or child-must earn nature's gift by knowing nature directly, however difficult it may be to glean that knowledge in an urban environment.

Nature-the sublime, the harsh, and the beautiful-offers something that the street or gated community or computer game cannot. Nature presents the young with something so much greater than they are; it offers an environment where they can easily contemplate infinity and eternity.

It's easy to blame the nature-deficit disorder on the kids' or the parents' back, but they also need the help of urban planners, schools, libraries and other community agents to find nature that's accessible.

Research suggests that exposure to the natural world - including nearby nature in cities - helps improve human health, well-being, and intellectual capacity in ways that science is only recently beginning to understand.

When we raise our children, we relive our childhood. Forgotten memories, painful and pleasurable, rise to the surface.... So each of us thinks, almost daily, of how our own childhood compares with our children's, and of what our children's future will hold.