(The Conversation is an independent and nonprofit source of news, analysis and commentary from academic experts.)

(THE CONVERSATION) If humans created an emissions hall of shame, which pollutants would you nominate?

Carbon dioxide and methane would probably be fan favorites. But take a moment and consider my dark horse candidate: sulfur dioxide. Unlike its carbon-based counterparts, sulfur dioxide is not considered a major greenhouse gas and doesn’t get as much attention in the media. Instead, it does its dirty work in other ways.

Sulfur dioxide is emitted primarily through the burning of foss...