But before the picture of the world dying and the decay of the old Sather's pride, even Hanson's own probable death with the dying world seemed unimportant.
Hanson had to do something to save the world. 
mnli hypothesis: Hanson had to do something to save the world.  premise: But before the picture of the world dying and the decay of the old Sather's pride, even Hanson's own probable death with the dying world seemed unimportant.