[captions made possible by kcet television] >> today on "earth focus," children's book author lynn cherry captures youth making positive changes for the earth in her original film series "young voices for the planet." coming up on "earth focus." >> the mountains of maryland, lynn cherry spends many of her days over a drawing table. she has been writing and illustrating children's books for over 30 years. >> the most popular is the great tree, and that's the tale of the amazon rain forest in which a man goes down to the forest and cuts down a tree and all the animals whispering in his ear while he's sleeping and he wakes up and he has an epiphany and he doesn't cut the tree down. and it's about power for one person to do good or harm. >> lending her talent as an artist, lynn has devoted much of her recent work to climate change, even publishing a book specifically designed for children and parents. >> i think that my interest in the environment grew out of my love for nature. i had an experience when i was a little kid where i had these woods that i loved and i came pack and they were bull