That article only mentions half of the story. Yes, the rain was slightly acidic. Plants loved this. (When most people hear the word acid, they think of cartoon acid eating through a table.) But acid rain isn't like that. Plants thrived in acid rain. Now, chemical fertilisers add acid to the soil, improving crop yields. These fertilisers wash out of the soil into rivers, and then out to the ocean. A few years ago when they were pushing the ocean acidification narrative, they said it was from "agricultural runoff". Making people think that it was from cows and pigs, when it was really from increasing crop yields. But the truth is that if we are going to feed 8 billion people, and we're going to do that with plants, then we have to continue to turn the ocean acidic. - So they shut up about it.