The movie Battle for Terra is coming out this Friday. It's an animated film about an alien world that humans invade when our own planet is destroyed by our excesses. The movie is really only for ages 10 or 12 and up because of some complex themes (and decisions characters have to make that I didn't want my 7-year-old to think about), but it's beautifully designed and the story is a twist on the classic "alien invasion" theme.
They're running a contest for 3rd to 8th graders with a grand prize of a California community service adventure on the website here. It looks like a very cool prize, so if you have older kids who are interested in animated action movies and conservation, check out the movie and the contest.