I mean sulfur is also a natural part of our atmosphere that geologic activity has been spewing out into the air for as long as earth has had air, but I’m still going to call it pollution if you’re power plant pumps a vast quantity of it into the atmosphere and now it’s raining acid on me.
We have more than doubled the amount of carbon dioxide in our atmosphere, with half of that doubling having been done in the last thirty years alone. The very oceans are acidifying to the point large swaths of marine life are being wiped out, and thousands to hundreds of thousands of people are being killled by the effects of global warming each and every year. It’s pollution, it’s just the pollution is on such a vastly larger and more dangerous scale than any acid rain or smog people are used to thinking about.