In the movie 2012 What was the main causes of earth destruction explain add soem geographical explantions?

FOR 10 POINTS if you watched the movie "2012" what was the cause of the earths destrtucion and what caused the earths crust and core and sunlight radiotion affecting bla bla can someone explain based on the MOVIE i need a full explanation based on the movie not from wikipedia or frm the plot IN UR OWN EXPLANATION after watching the movie.. i know the movie is fictional i just need to know the real thing the cause of earths destruction in the movie plz explain