No, that's not a cause of climate shift over there. Geology is. The middle east is formerly ocean floor, and before that it was carboniferous swamp. The rising of the landforms resulted in the change to arid climate, not a meteor impact.
In any case, a natural disaster like an asteroid strike or a volanic eruption or something is on a really tiny scale compared to what we're talking about here. An asteroid is nothing compared to a 30% pH change in seawater, or even a very slight temperature change.