According to Dr. Rattan Lal of Ohio State University, a pioneer in the study of “biosequestration” (using plants and microbes to sequester carbon dioxide), humans have put some 500 gigatons (billion tons) of carbon dioxide into the atmosphere since the birth of agriculture some ten thousand years ago. But most of that CO2 was emitted during the relatively recent advent of modern agriculture. Through plowing the land, which releases tremendous quantities of CO2, deforestation, urbanization, and land-use change we have effectively taken a massive quantity of carbon that used to be stored in the ground and released it into the atmosphere.
In addition, about 250 years ago humans began to burn copious amounts of fossil fuels. That added another 350 gigatons of CO2 to the atmosphere (half of which have been produced just since 1980). Total it all up and we’ve put some 850 gigatons of CO2 into the air. For now, the majority of CO2 humankind has released since the birth of civilization has come from plants and the soil.
- Quoted from Kiss the Ground: How the Food You Eat Can Reverse Climate Change, Heal Your Body & Ultimately Save Our World by Josh Tickell and John Mackey.