Plot hole: Dan returns from the future with a vial of toxins with him that can kill all the white spikes. He tells somebody to start mass-producing it but this information is not spread across governments or even made public, but it is the one thing they have that can prevent humanity's extinction and making people aware of that will stop the rioting.
Factual error: The aircraft launched to destroy the city of Miami are F-22 air superiority fighters, which are entirely incapable of saturation or carpet bombing. Even the way they carry out the operation in the movie demonstrates this. They blow up a few streets and that's it. What was the point?