Agricultural intensification has significantly reduced greenhouse gas (GHG) emissions compared to land expansion. Between 1961 and 2005, increased crop yields avoided up to 161 GtC (590 GtCO₂e) in emissions, equivalent to 3.6 GtC per year. This is more effective than many other mitigation strategies. The study compares two scenarios: AW1, where yields remained constant and land expanded, and AW2, where per capita production was maintained through extensification. AW1 required 1,514 Mha more cropland, while AW2 needed 864 Mha more. Agricultural intensification avoided 161 GtC of emissions, equivalent to 34% of total human emissions since 1850. The cost-effectiveness of yield improvements is high, with carbon prices ranging from $7.16 to $13.32 per metric ton of carbon. The study highlights that enhancing crop yields can reduce emissions while meeting food demand, and that continued yield improvements are crucial for future climate mitigation. The findings suggest that agricultural intensification has been more effective than land expansion in reducing GHG emissions, and that further yield improvements should be prioritized in climate strategies.Agricultural intensification has significantly reduced greenhouse gas (GHG) emissions compared to land expansion. Between 1961 and 2005, increased crop yields avoided up to 161 GtC (590 GtCO₂e) in emissions, equivalent to 3.6 GtC per year. This is more effective than many other mitigation strategies. The study compares two scenarios: AW1, where yields remained constant and land expanded, and AW2, where per capita production was maintained through extensification. AW1 required 1,514 Mha more cropland, while AW2 needed 864 Mha more. Agricultural intensification avoided 161 GtC of emissions, equivalent to 34% of total human emissions since 1850. The cost-effectiveness of yield improvements is high, with carbon prices ranging from $7.16 to $13.32 per metric ton of carbon. The study highlights that enhancing crop yields can reduce emissions while meeting food demand, and that continued yield improvements are crucial for future climate mitigation. The findings suggest that agricultural intensification has been more effective than land expansion in reducing GHG emissions, and that further yield improvements should be prioritized in climate strategies.