Carbon capture and sequestration... Could it be the silver bullet that saves our planet from a catastrophic climate change? Or might it present risks of its own? A mysterious deadly vapor suffocates a small American coal town. CO2 follows a determined group of survivors as they attempt to survive and escape.

Sheriff Sean Kilpatrick is a pacifist. Frank Brand is the leader of a band of killers. When their paths cross Kilpatrick is compelled to go against everything he has stood for to bring death to Brand and his gang. Through his hunt into Mexico he is challenged by a noble Mexican Sheriff interested only in carrying out the law - not vengeance.