<P> Human activities since the beginning of the Industrial Revolution ( taken as sometime between the years 1740 and 1754 ) have produced a 40 % increase in the atmospheric concentration of carbon dioxide , from 280 ppm in 1750 to 406 ppm in early 2017 . This increase has occurred despite the uptake of a large portion of the emissions by various natural `` sinks '' involved in the carbon cycle . The vast majority of Anthropogenic carbon dioxide ( CO ) emissions ( i.e. , emissions produced by human activities ) come from combustion of fossil fuels , principally coal , oil , and natural gas , with comparatively modest additional contributions coming from deforestation , changes in land use , soil erosion , and agriculture ( including animal agriculture ) , though some of the emissions of this sector are offset by carbon sequestration . </P>
<P> Human activities since the beginning of the Industrial Revolution ( taken as sometime between the years 1740 and 1754 ) have produced a 40 % increase in the atmospheric concentration of carbon dioxide , from 280 ppm in 1750 to 406 ppm in early 2017 . This increase has occurred despite the uptake of a large portion of the emissions by various natural `` sinks '' involved in the carbon cycle . The vast majority of Anthropogenic carbon dioxide ( CO ) emissions ( i.e. , emissions produced by human activities ) come from combustion of fossil fuels , principally coal , oil , and natural gas , with comparatively modest additional contributions coming from deforestation , changes in land use , soil erosion , and agriculture ( including animal agriculture ) , though some of the emissions of this sector are offset by carbon sequestration . </P>
what is the most important gas in the greenhouse effect
what is the most important gas in the greenhouse effect
carbon dioxide
carbon dioxide