Comment Re:Abrupt, but like 100 years abrupt? (Score 3, Informative) 132
And for all those who argue we are burning too much fossil fuels, those carbon atoms weren't created into existence in the ground as they were today, unless you believe the earth is 6000 years old!
They were a part of the global carbon cycle, and buried during mass extinction events and processes that sequestered them to where they are today.
Ummm, close, but no. It was sequestered over hundreds of million years to billions of years but the bulk of the carbon from the carbon cycle is tied up in a few places, neither of which has anything to do with mass extinctions. The huge bulk of CO2 ( currently ~400PPM atmosphere, ~60*atmosphere dissolved in the oceans, and ~10,000*oceans+atmosphere is tied up in rocks ) is tied up in the carbonates, I.E. limestones and dolostones. Coals come from swamps, and oil comes from mostly shallow-ish marine bacteria that had periodic blooms and die-offs that settled into the sediments on the seafloor and got buried.