The Day the Earth Stood Still
In The Day the Earth Stood Still Keanu Reeves stars as Klaatu an alien sent to save the earth from its human inhabitants. Since humans are destroying the planet, the aliens want to save all life on earth except for the humans, to let everything regenerate. He says that without the earth, humans would disappear. But without humans, the earth would thrive. Klaatu makes a dramatic entrance, and of course, people freak out and the government goes into defense mode, proving the point that humans are destructive.
Jennifer Connelly plays a scientist who is recruited involuntarily by the government to figure out what is going on. She has a step-son, played by Jaden Smith, confused and scared by all the activity. He represents the future of humanity, and she represents the compassion. So we’re not so bad after all.
This is pretty standard sci-fi. Some good special effects, but for the most part predictable.