"Pediatricians nowadays see fewer kids with broken bones from climbing trees and more children with longer-lasting repetitive-stress injuries, which are related to playing video games and typing at keyboards," writes Sally Deneen. Richard Louv, author of Last Child in the Woods, calls this "nature deficit disorder." As a fourth-grader quoted in Louv's book explains: "I like to play indoors better, because that's where all the electrical outlets are."

Nature deficit disorder is obviously not a medical term; it's more of a social trend. The term describes "the human costs of alienation from nature, among them diminished use of the senses, attention difficulties and higher rates of physical and emotional illness." Deneen concurs: "We're raising the very first generation of Americans to grow up disconnected with nature, he says, and this broken relationship is making kids overweight, depressed and distracted."

"The truth is that children today spend far too much time cooped up at home with their tushies parked in front of the television or PC," says Jasmin Malik at TreeHugger. She adds: "American children between the ages of 8 to 18 spend an average of 6.5 hours a day indoors using computers, video games, television, and MP3 players."

The National Wildlife Federation (NWF) recommends that parents give their kids a "Green Hour" every day, "a time for unstructured play and interaction with the natural world. This can take place in a garden, a backyard, the park down the street, or any place that provides safe and accessible green spaces where children can learn and play."

The NWF reports that children who regularly spend unstructured time outside:

-Play more creatively

-Have lower stress levels

-Have more active imaginations

- Become fitter and leaner

- Develop stronger immune systems

-Experience fewer symptoms of ADD and ADHD

- Have greater respect for themselves, for others, and for the environment

Got a tip or a post idea for us to write about on Planet Green? Email pgtips (at) treehugger (dot) com.