See title. With the rise to 455 ppm of CO2 (and likely higher for a while), I wonder what the lowest Earth’s had, was.
If I’m not mistaken, the highest was during the Permian-Triassic mass extinction, in where the Siberian Traps may have been responsible for making burrowing – and hence adaptations for stale air – necessary?
During the Carboniferous period after trees developed but before fungus developed the ability to break down cellulose.
Trees pulled lots of carbon from the atmosphere and sequestered it, but nothing was capable of breaking them down so they just piled up, literally. It was enough to cause a cooling event.
Not a scientist or geologist. But I can recommend the Wikipedia article about Carbon dioxide in the atmosphere. Or one of the TV documentaries about the ice core drillings in the Antarctic.
