Actually, in the film, the earth does both. First, we learn about the shift in the change in the axis of the earth, by 11 degrees, which added (presumably) to the 23 1/2 degrees already, nearly a 50% increase. This is what causes the bizarre shifts in weather patterns: the fog scene in England, the snow in New York, etc.
But later on, in the climax of act two, we also learn that the earth's orbit has been shifted and that earth's orbit is now slowly spiraling inward to move the earth closer to the sun. This is what leads to the heating up of the earth. There is a big montage sequence showing scenes of fires, water shortages, and so forth.
It's a terrific film.
Not the least for showing all the politicians denying that everything is happening !