Plant trees
Planting trees is an effective way to help the Earth as trees are oxygen filters and provide shelter and food to many animals. If you live on a farm or have some land, you can make a day of planting trees with your kids. The Arbor Day Foundation also organizes tree-planting events that kids can participate in.
Beach Cleanups
Kids can help clean up polluted beaches by participating in the International Coastal Cleanup. The cleanup is scheduled every year. In 2009, 1.1 million plastic bags were picked up by volunteers during the event. However, children wanting to help the Earth don't have to wait for the International Cleanup to take place--programs like the 30-minute beach cleanup in Long Beach, CA, are scheduled on a monthly basis.
Save Water
Because only 1 percent of the Earth's water is available for humans to consume, kids can help the Earth by using less of it. Instead of wasting water by leaving the garden hose running, children can water plants with water cans. An excellent teaching tool is the shower estimation experiment from PBS Kids. This experiment enables children to see how much water they can save by turning off running faucets.