Go and see this movie. Being a geologist, I really enjoyed the part with the Yellowstone eruption (fig. 1). Although 99% of the stuff happening there is far beyond being realistic, the explosion of a caldera appears to be more or less like that (according to what I learned in my volcanics-class). However, the pyroclastic cloud in the movie appears quite comfortable. A real one probably wouldn't release an aircraft that it once caught.
Apart from the CGI earth decomposition, which is well done, I would recommend to movie directors to throw all this emotional crap away and add self-irony and dirt instead. The pretence to create a movie which tries to sell family-compatible ethics although there is terror and destruction everywhere just doesn't work. All of this pathos really destroyed the movie more than the earth has been destroyed in the movie. Haha, but that's okay, they want to earn money. I understand that.
My wish: just show the cool parts and add cool music. I found the following clip on youtube which is pretty close to what I imagine: