Omission
Explanation
The Joke
Someone enthusiastically describes a hydrogen fuel cell vehicle: "And the amazing thing is that no pollutants come out of the tailpipe! Just pure water!" When asked how it works, they explain: "I split the hydrogen from the oxygen using electricity created by a coal-fired power plant, then I use fat from an endangered family of blue whales" (or similar absurd, environmentally destructive process).
The caption at the bottom reads: "This is what I visualize every time someone refers to fuel cell vehicles as 'emissions free.'"
The Humor
The comic targets the common claim that hydrogen fuel cell vehicles are "emissions free" by pointing out the lie of omission in that framing. While it's technically true that the car's tailpipe only emits water, the full lifecycle of producing, compressing, and transporting hydrogen often involves significant carbon emissions and energy use — the pollution is simply displaced upstream.
This is a well-known criticism in environmental science called "well-to-wheel" analysis versus "tank-to-wheel" analysis. By presenting an absurdly exaggerated version of the upstream pollution (involving endangered whales and coal plants), the comic makes the logical point memorable: calling something "emissions free" based only on what comes out of the tailpipe is like calling a restaurant "waste free" because the dumpster is in the alley.
Weinersmith frequently uses this technique of taking a common misconception and dramatizing the hidden absurdity to make the underlying logical error obvious.
Votey
The red-button panel typically adds an additional punchline that extends or undercuts the comic's premise.