Dr. Blight attacks Hope Island, utilizing a smog-fueled barge. She creates a huge dome over the island and feeds her smog supply into the dome, creating a "greenhouse" effect which threatens Gaia's life and that of the Island. If things couldn't get any worse, the greenhouse effect prevents the Planeteers from activating their powers and calling on Captain Planet! Only with the aid of a giant whale can the Planeteers hope to escape their domed environment and summon earth's protector to stop Blight cold.
Elenco: Frank Welker , Joey Dedio , LeVar Burton , Whoopi Goldberg , Janice Kawaye , Kath Soucie , Scott Menville , Buster Jones , Clyde Kusatsu , David Warner , Dean Stockwell , Edgar Gilbert , George Hearn , James Coburn , Jim Cummings , Lewis Arquette , Margot Kidder , Martin Sheen , Tim Curry , Whoopi Goldberg .