That’s the rate that people are releasing carbon to the atmosphere from fossil fuel combustion and deforestation today. I know, it’s apples and oranges; carbon in the form of oil is more immediately toxic to the environment than it is as CO2 (although CO2 may be more damaging on geologic time scales). But think of it — five thousand spills like in the Gulf of Mexico, all going at once, each releasing 40,000 barrels a day, every day for decades and centuries on end. We are burning a lot of carbon!