“In this study, the authors do a really good job of quantifying how humans have altered the Earth’s surface soil carbon stocks through extensive agriculture, with direct implications for atmospheric CO2 concentrations and the climate.”
“The model suggested that agricultural changes are responsible for the loss of a total of 133 petagrams, or 133 billion metric tons, of carbon from the top six-foot-deep layer of soil all over the world. The most intense losses per unit of land have been caused by the planting of crops — however, more land worldwide is devoted to grazing livestock than cropping.”