https://whatsyourimpact.org/greenhouse-g...-emissions 90 percent of all human-produced CO2 contributes to carbon emissions 90 percent of all human-produced CO2 source of CO2 emissions source of CO2 emissions 90 percent of all human-produced CO2 major factor in anthropogenic climate change footprint. https://whatsyourimpact.org/greenhouse-g...-emissions source of CO2 emissions