>>509501667Atmospheric CO2 now is lower now than it has ever been in geologic history. Photosynthesis will become impossible in another 300 million years because it all gets buried underground and volcanism is insufficient to counter this, especially as the Earth's core cools and becomes less geologically active. Carbon is being stripped from the surface of the earth and sequestered deep underground. The destiny of the human race is to counteract this process and return it to the world above.