Given the not-inconsiderable assumption that you could effectively move a body that size in the first place, you would actually have to TRY to hit the Earth with it. Not going to happen by accident.

Of course, when it comes down to it, I probably would not support doing something like cutting off a portion of sunlight in the first place unless there was absolute proof that the amount coming from the sun is somehow historically unprecedented, which I have not seen.

The Earth is a complex ecosystem, and too many of the "big ideas" I've seen are the equivalent of fixing a computer by kicking it..