Towards site-specific Greenhouse Gas emissions measurement: rice production in Colombia

Globally, the AFOLU (Agriculture, Forestry, and Other Land Use) group shares 22% of anthropogenic Greenhouse Gases (GHGs) emissions (IPCC, 2022a). For Colombia, this group rises to 59% (IDEAM et al., 2021). AFOLU group, is also one of the sectors most affected by the climate change effects and have itself a high GHGs mitigation potential (FAO, 2021a). Therefore, estimating GHGs emissions in this sector is a fundamental process for generating national inventories that enable the development of low-emission national strategies and adequate mitigation measures for decision-makers. In this study, we calculate the rice cultivation emissions of 604 farmers in six different departments of Colombia, for this, we used the IPCC methodology (Tier 1) and, as input, a socio-economic household survey carried out face-to-face in November 2020 for 616 producers. We calculated a mean emission of 2.6 ton CO2 eq ha-1 per crop cycle, with methane as the main contributor (56.5%). At a departmental level, Valle del Cauca reported the highest mean emissions (4.4 ton CO2 eq ha-1) followed by Tolima with 4.0 ton CO2 eq ha-1, both of them well above the mean and with a significant statistical difference. Casanare and Meta, which are mainly under rainfed systems, evidence a good balance between mean emissions per hectare and mean emissions per ton of paddy rice produced. This study contrasts with the usual general measurements calculated in national inventories, thus obtaining a more site-specific overview of the emissions from rice cultivation, which is helpful for organizations, research centers, and the national government to make better decisions on mitigation actions. Lastly, we recommend focusing mitigation efforts on reducing methane emissions mainly in irrigated rice crops.