According to Phil Plait (Astronomer, famous blogger and overall cool guy), the scientific community is divided on what would be worse, having a big meteor hit the Earth in 1 piece, or having a millions of small piece of the same meteor hit the Earth, as the damage in that case would be just as severe, just more wide-spread, yet that's exactly what we see happening in this movie and "saving the world". Arceus might as well not have shown up, and there's no way Damos should've survived that either way.
Not that in the meteor in this movie seems big or anything, would've probably left a pretty cool crater, but that's it...
This was the 1st thing I saw of the movie, BTW. Pretty boring, when Arceus appeared was kinda alright, and when he turned the land back to green, then turned it back and was like "lolpwnd" kinda made me smile, but that's it. And Arceus' voice sounds silly and very human, which just shouldn't be right.
Also, the background music was trying too hard.