A global meta-analysis of 568 comparisons across 137 studies found that replacing chemical fertilizers with organic ones significantly reduces N2O emissions but increases CO2 and CH4 emissions, raising the global warming potential (GWP). Optimal GWP reduction involves adjusting organic C, C/N ratio, and N substitution rate. Drylands benefit more from organic fertilizers, while paddy fields need careful management to mitigate GWP increases.