Flexi Says: The researchers from the University of Tokyo and Chris Reinhard of Georgia Tech had found that after a billion years from now, the earth would become inhabitable as the amount of oxygen will reduce to around one-millionth as per the climatic, biological, and geological changes. Also, the solar radiance will increase by 10% leading to a higher rate of evaporation of water from oceans and disappearance of plate tectonics and carbon cycle.
