Here's a clip from one of my favorite people, Bobby Hemmitt. A brother who pulls no punches whatsoever. His theories are quite extraordinary, and this hypothesis particularly strikes me.
For those who can't yet watch the clip, Hemmitt is surmising that the word N!gger is rooted in an ancient African term NGGR(nay-gar), which raises the Kundalini spirit. The Kundalini spirit is also known as the serpent power, and when risen, it can elevate one's spirit to be closer to God. It basically represents a spiritual maturation.
Hemmitt says that the rising of the Kundalini spirit is what prompts Global Warming, not noxious gases. Shit had me bugging for a minute. I'll let him tell the rest.