From Dr Ed Berry in U.S.: "New calculations prove all human CO2 emitted since 1750 has added only 31 ppm (parts per million) of CO2 to the atmosphere, and natural CO2 has added 100 ppm. All human carbon has added only one percent to the carbon in Earth’s carbon cycle. Nature has added much more carbon to the carbon cycle than humans have added. The new calculations use data from the United Nations Intergovernmental Panel on Climate Change (IPCC)."