Gaia, the spirit of the planet, assembles a diverse team of "planeteers," who are able to combine their powers to summon an elemental warrior that takes on the appearance of superhero Captain Planet. He works with the planeteers to defend Earth from pollution caused by criminals and villains. As the show's theme song says, Captain Planet is "gonna take pollution down to zero" by defeating the villains, who include the likes of Hoggish Greedly, Dr. Blight and Looten Plunder. The animated series was co-created by media mogul Ted Turner, a noted environmentalist.

The Planeteers stay at a rich man's upscale hotel, but when staff treats Ma-Ti like a street thug, he heads off on his own to investigate life among the local lower-class community.

When a blizzard traps the Planeteers on Mount Everest, a group of talking animals comes to their rescue, but then puts them on trial for humanity's destruction of Earth's ecosystems.

The Planeteers and their friend Milton explore preservation efforts along the Mississippi River.

The Planeteers must stop Looten Plunder and Hoggish Greedly's destructive mining and cattle rustling ventures in the African wetlands.