After Earth -- movie, controversy, and science

Summary:

Katai Raige and his father, Cypher, are the only survivors from a crash landing on Earth. Cypher, who has a broken leg, has to guide his son to the signal beacon so that they can be rescued. The problem is that Katai hasn't yet become a ranger because his emotions are uncontrolled. That's a problem when the alien predator pursues its prey by the smell of fear.

Controversy: This movie received much flack before it even came out:

1. It starred father and son, Jaden and Will Smith. "Nepotism," some complained, but this should not have gotten much traction since Jane and Henry Fonda starred together in On Golden Pond. The complaint may have stemmed from the next two. 
2. M. Night Shyamalan's movies have fallen in the critical eye since The Village. Perhaps people expect The Sixth Sense (which admittedly was extraordinary). But his films are enjoyable. It'd be curious to see how critics reacted if they didn't know Shyamalan had directed them. They'd not be critical hits, but good entertainments. 
3. This article about L. Ron Hubbard and After Earth links the two. It made me want to see the movie. I'm not sure what people fear from others' beliefs. People are made differently, so they will think differently than you. That's half of what speculative fiction's about.
4. It may upset some that emotions should be controlled; therefore, acting emotions were ridiculed to make a point. (Granted, I watched this in Spanish, so I missed out on the actors' verbal intonations.)

It's a solid entertainment, with a valid if unsubtle point to make (see poster). Once again I side with IMDB over Rotten Tomatoes. Watch it for futuristic survivalist fun.

Science:  

1. We have an asteroid storm, which would probably be rare due to collisions and gravity. Maybe a large collision just occurred, but can't they drive around?
2. I'm not sure what the inhalers do, but we can ascribe that to futuristic magic--as much of the other scientific complaints. 
3. The most fascinating speculative element was the sudden temperature drops. What brings them about? Decreased atmosphere? Increased distance from the sun? A change in axial tilt plus fast fluctuations in wind patterns? It's unclear, but the life on the planet would be quite different:
1. Plants and animals that survived would need a dual ability to survive both. 
2. After a thousand years, the flora would be very hardy. 
3. Life near natural heat sources would likely be unique from surrounding areas, but likely less evolved.
4. Fauna near heat sources would be familiar to us, and they'd likely have figured out what time to come home.
5. Other fauna would be more related to our polar and tundra friends.

In other words, a very different Earth than the one we know. To me, story science is just a jumping off point to think about your subject, not a point to yell about a. It's a tool to get people talking about what's real science and what's not.