• Abusive Parents: Wheeler's alcoholic father is the whole reason he left home.
• The Ace: Captain Planet himself, which is kind of unusual for a Five-Man Band type show in that he himself is not technically part of said band.
• Achilles in His Tent: Ma-Ti in "Rain of Terror" and Kwame in "Kwame's Crisis".
• Actor Allusion: Bambi Blight is voiced by Kath Soucie. In the episode wherein Bambi is involved with filming a movie, Dr. Blight swaps outfits with her and pretends to be her. Cue Bad "Bad Acting" and the director saying "We'll have Kath Soucie dub her lines in". Linka expresses her hopes that Kath Soucie is good - and Linka is also voiced by Kath Soucie.
• Added Alliterative Appeal: In the end credits, the part listing the voice actors for the Eco-Villains is labelled "Portraying Polluting Perpetrators".
• Adult Fear: Consider how much danger the characters are regularly put in, it's predictable that many of it would deal with the kinds of peril that parents and adults who care about children would be terrified of. Especially Ma-Ti, who is in one episode tied to a chair in a burning building with another kid.
• One episode features Linka's cousin Boris, who is about her age, being injured and subsequently dying as a result of drug overdose. Another features kids about the age of the other planeteers engaging in group violence (as in, buying guns illegally) while another features Free-Range Children in New York possibly being used as scapegoats for Skumm's plots, while another is flat out killed off-screen after jumping on a train because he hit the tunnel.
• Unlike most kids' cartoons, where the villain simply wants to get the heroes out of the way of their plans, the villains here will try to not only murder the Planeteers, but even other children who stand up to them. And in "Future Shock", a child is the villains' target as her death would alter the future in their favor.
• Even villains aren't immune to this. In one episode, Hoggish Greedly mass-produces a smog-generating car and the added pollution eventually becomes harmful to his son, making him desperate enough to beg the Planeteers to summon Captain Planet.
• An Aesop: "Bitter Waters" is about Looten Plunder actually showing a rare Pet the Dog moment - he wants to open up an agricultural firm on the reservation, which will provide its residents with jobs and money. However, where he messes up is the fact that he is using cash crops that are a little too thirsty for the land it grows on, which is very similar to what happened in the Soviet Union when they tried to grow cotton. In the end, he even admits their ideas were better when they use native and more appropriate agricultural products and use the land for green energy plants. The moral of this story is that the road to hell is paved with good intentions after all.
• Alike and Antithetical Adversaries: The series uses Heterogeneous Heroes against Homogeneous Villains. The Planeteers are multicultural, while the Eco-Villains are pretty much all white Americans.
• A.I. Is a Crapshoot: Averted-ish. MAL, Dr. Blight's computer henchman, was originally a nice AI who liked to play games, but was reprogrammed by Blight into his current malicious incarnation. He was reverted to his original programming in one episode and then proceeded to help the Planeteers.
• He's also clearly in love with the bad doctor, and is very loyal to her.note
• All Just a Dream: Combined with social Aesops like overpopulation and homelessness, it's something of a Running Gag for Wheeler to end, up one way or another, entering a dream world or alternate universe to teach the day's lesson.
• All Your Colors Combined: The net effect of summoning Captain Planet, since each of the rings has a different color associated with it. Also the Trope Namer.
• Allergic to Evil: Captain Planet is hurt (as in harmed, not merely upset) by Adolf Hitler's hatred, which is here considered to be a form of emotional pollution.
• Analogy Backfire: One episode dealt with the ethics of putting animals in zoos to preserve their population by having an alien race arrive and put the Planeteers and the extras of the week into a zoo for their own preservation. The aliens made the exact same excuses, such as "it's for your own good," that humans had made for doing so earlier. This episode has multiple failed analogies:
