claim: Human additions of CO2 are in the margin of error of current measurements and the gradual increase in CO2 is mainly from oceans degassing as the planet slowly emerges from the last ice age.
evidence: The burning of long-buried fossil fuels releases CO 2 containing carbon of different isotopic ratios to those of living plants, enabling distinction between natural and human-caused contributions to CO 2 concentration.
category: Carbon dioxide in Earth's atmosphere