In Justice League: The Flashpoint Paradox, The alternate future where the world is going to end, Zoom has the idea of the chain of the event changes caused by flash. How is this possible..?
Professor Zoom taunting over the death of Flash's mother is responsible for the timeline change. It is revealed in the end that Flash is responsible for the creation of alternated world because after Zoom's taunting, he traveled back in time and save his mother. This create chain of event which led the world to this destructive situation. Doctor Zoom just took profit of the situation.