ANSWER THESE QUESTIONS & I MIGHT WATCH "SNOWPIERCER"

Thanks in advance
  1. What is wrong with Earth?
  2. Why does living on a moving train help that?
  3. How is it the train is able to stay in operation? What is powering it/how is it repaired after inevitable breakdowns/is nothing ever wrong with the tracks?
  4. How exactly does a stratified economic structure develop aboard the train/what IS the economy there?
  5. Does the train pierce snow/how much snow/how often?