Christmas might not come this year because all the reindeer are being killed off by global warming, and so Santa is not going to have anyone to pull his sleigh.
Okay, I jest. Still, the part about reindeer being killed off by global warming is true. Some suggest 80,000 have been killed in the past decade. What's happening? They're starving. Typically, they can kick through a thin sheet of ice to get to frozen pasture and eat. But, with warming temperatures, an effect is created that causes evaporation that, in turn, causes more raining. Then, the rain water freezes, and with the increased amounts of rain, the ice sheets are thicker than usual -- too thick for Rudolph to kick through.
And, the red-nosed reindeer dies. This doesn't make for a pleasant Christmas story.