The Earth's increasing surface temperature will accelerate the inorganic CO2 cycle, reducing its concentration to the lethal levels for plants (10 ppm for C4 photosynthesis) in 900 million years. The lack of vegetation will result in the loss of oxygen in the atmosphere, so animal life will become extinct within several million more years.[24]

But even if the Sun were eternal and stable, the continued internal cooling of the Earth would have resulted in a loss of much of its atmosphere and oceans (due to lower volcanism).[131]

After another billion years the surface water will have completely disappeared[132] and the mean global temperature will reach 70°C.[24]

The Earth is expected to be effectively habitable for another 500 million years or so.[133]