Unpacking the growth of global agricultural greenhouse gas emissions

Agriculture, forestry, and other land use contribute about a fifth of total anthropogenic greenhouse gas (GHG) emissions. Mitigation efforts have emphasized “decoupling” that sustains production while lowering emissions per unit of output. However, the underlying decoupling mechanisms have not been fully characterized. We rely on a mathematical identity to decompose agricultural GHG emission growth ( Δ E ) into three parts: output ( Δ Y ), emissions per unit of input ( Δ E / X ), and output per unit of input ( Δ Y / X ) or total factor productivity (TFP). We then rely on official country-level data to quantify the historical contribution of these components. Over 1961 to 2021, we find that TFP growth—which captures the sector’s ability to produce more output per unit of measured input—has consistently remained one of the main sources of GHG emission reduction within farms. Further decomposition reveals a key role for rising land productivity in reducing emission intensity.