There's a section in the Book of Mormon (Mormon 8: 29, 31) that says: "Yea it shall come in a day when there shall be heard of fires, and tempests, and vapors of smoke in foreign lands; ... Yea, it shall come in a day when there shall be great pollutions upon the face of the earth." It's talking about the emergence of the Book of Mormon in our time. So it's talking about today when it mentions these vapors of smoke, and great pollutions.
I thought of that scripture when I saw this article:
I guess that's one revelation that's certainly true. It's creepy to me to think about the sun slowly getting blocked by crud in the air though... I'd rather that didn't happen! How 'bout you?