co2 on geologic time scales
My previous blog article showed CO2 concentration in the air over the last 800'00 years.
Our species - homo sapiens - is considered to have appeared only about 200'000 years ago, which is inside the scope of the time scale of the previous blog post.
If we go three orders of magnitude further back (1000 million years instead of one million years), then the CO2 concentration graph looks a lot different than within the last 1 mio years:
source: Monte Hieb, http://geocraft.com/WVFossils/Carboniferous_climate.html
On these time scales there were periods where we had subtropical forests in Greenland, glaciers reaching the equator and saw repeated extinctions of large numbers of species and large parts of life on earth and continents had different forms.
Multicellular life only started about 500 mio years ago.
Tomáš Pospíšek, 2016-11-21