Kinda missed all the marks here....
Hey, everyone is allowed a political opinion, and every can have theories as to what will cause the end of the world. (Yes, I've seen "The Day After Tomorrow" about 3 times, as well as countless Asteroids vs. Earth - type Sci Fi.)
This flash really didn't make the point. The animation and art style detracted from the message - which vacillated between being preachy and being ominous. The background song, which in itself was audibly OK, was another miss. I would think that the song would have been something more urgent or darker.
I can understand the importance of what you are trying to say - that this is the only planet we have, and if we don't take care of it, it'll put us back in our place. That's why you got a "3" - the idea was good, but the flash didn't do justice to the message.
Also, if you are going to animate a theory such as this, might I recommend doing a little research, and then posting the source of the research in the ending credits? This way, you can avoid the "where did you get your info from" questions.
Get some solid facts, and think about reworking this so that the audio and visual components flow together better. I think you can do better - you're on the right track...
And, yes, NO ONE really knows how it all ends. But we who live on the 3rd rock from the Sun should try to avoid hastening our own demise.