Possible.
I'd need a lot more data. But given the number of burning cities in WWII, if you are right, does the red dip in the graph seem like a realistic prediction?
Another thing nobody has noticed yet, is that this theory discards the current conventional wisdom that an Islamic nation would not attack an enemy with atomic weapons because of deterrence. I am hearing this a LOT on the subject of Iran and Israel.
That premise and the "big chill" are mutually exclusive.