Factual error: If, as the film proposes, all plant life is dead, then human life would have soon followed it. Since plants filter carbon dioxide from the atmosphere, then a lack of plants would allow for the increase of that CO2. And since the the unknown disaster appears to have been the result of a super volcano, the additional CO2 would be accompanied by the gases from the volcano making the atmosphere even more toxic.
Factual error: Despite being on the Atlantic shore, the scene in the devastated amusement park opens with a shop of a sign saying it is Conneaut Lake Park. (You can also see the landscape on the other side of the lake in the background.) The scene was filmed not long after a fire destroyed several historic buildings at the actual Conneaut Lake park in PA. Since they used CGI to alter the actual park sign (which is at the entrance to the park and not on its boardwalk, I have to wonder why they didn't create a sign for a boardwalk park. (01:27:35)
