Since it's near as no never mind to Earth Day, we're in for a classic strip about littering that conserves subtlety while making the same stupid point that the 'conserves water' strip did: no matter how we try to fix the environment, evil, lazy people thwart us because they're not as good as we are. Suffice to say that Walt Kelly did this better.
(Strip Number 6619, Original Publication Date, 7 September 1980)
Panel 1: As the Pattersons travel down the highway, we see Mike eating a bag of chips. It should be noted that Lizzie is reaching for said chips but it isn't clear if he's willing to share.
Panel 2: Michael, having finished his chips, CRUMPLE-CRINKLE-CRUSHes the bag into a little ball.
Panel 3: We switch to an exterior shot which depicts him TOSSing it out the window.
Panel 4: This doesn't exactly thrill John; he angrily tells Mike that he is NOT to throw trash on the highway.
Panel 5: As he makes a probably illegal U-turn, John tells Mike that they're going to turn around and he's going to pick that up.
Panel 6: Mike invites the rejoinder "But NOTHING" by whining "But Daddyyyyyyy."
Panel 7: As he and Mike stare goggle-eyed at the trash other careless, thoughtless morons have left behind, John thought-bubbles "Sometimes you wonder if a point is worth making." My answer to THAT whiny chunk of bull-flop is that it definitely is; it isn't as if it's okay to litter because other people are doing it or that Mike shouldn't be made to set a better example.
Summary: You just know that John is going to shake his head in despair and drive on without doing anything about the problem, don't you? I mean, he is a Patterson and that's their answer to the problems that face them: whine about how bad things are and give up.