Glyphosate use in agricultural production: it's contribution to global carbon dioxide emissions.

This paper estimates the annual global carbon dioxide equivalent (CO2e) emissions from the manufacture, distribution and farm level use of glyphosate and estimates the annual contribution of glyphosate to reducing CO2e emissions through its role in facilitating a shift in farming production practices that are tillage-based into conservation tillage systems based on reduced and no tillage. Total annual global use of glyphosate is 749.27 million kg of active ingredient, applied to 646.11 million (spray) hectares. The CO2e emission generated from the manufacture, distribution and application of glyphosate in global agriculture is annually 9.76 billion kg. The total global combined annual fuel and soil carbon retention-related CO2e emissions of conservation tillage are a net reduction of -138.2 billion kg CO2e. This compares with +41.47 billion kg CO2e emissions if this area had been plowed with conventional tillage practices. Therefore, conservation tillage practices provide a net reduction in combined annual fuel and increased soil carbon retention-related emissions of -179.67 billion kg CO2e relative to a conventional plow-based alternative production system. The total global combined annual fuel and soil carbon retention-related CO2e emissions of conservation tillage attributable to glyphosate is estimated at a net reduction of -41.93 billion kg CO2e. This compares with +13.01 billion CO2e emissions if this area had been plowed, providing a net reduction in combined fuel and soil carbon-related emissions attributable to glyphosate of -54.94 billion kg CO2e annually or the equivalent of taking 21.8 million cars off the road each year.