Analysis of spatially distributed enteric methane emissions from cattle across the geo-climatic regions of Mexico and uncertainty assessment

Angeles-Hernandez, J. C., Ku-Vera, J. C., Vázquez-Carrillo, M. F., Castelán-Jaime, S. V., Molina, L. T., Benaouda, M., Kebreab, E., González-Ronquillo, M., Paz-Pellat, F., Montelongo-Pérez, H. D., & Castelán-Ortega, O. A.

Atmospheric Environment |

Abstract

The present work aims to calculate a bottom-up IPCC-Tier 2 inventory for enteric CH₄emissions from cattle in Mexico, disaggregate the inventory into different geo-climatic regions to analyze the effect of the contrasting climates of Mexico on the inventory and identify the relevant sources of uncertainty associated with the inventory. Peer-reviewed country-specific emission factors (EF), activity data (AD) on animal characteristics, feeding management, and CH₄ conversion factors (Ym) were used in developing the emissions inventory. Monte Carlo simulation (MCS) was used to propagate the uncertainty throughout the Tier 2 model (T2model). Spearman-ranked correlation analysis (SRCA) was used to identify relevant input parameters (IPAs) for which CH₄emissions variables were most sensitive. The estimated inventory for the year 2018 was 2039 Gg CH₄ year⁻¹ with an uncertainty of −18.3 % to +21.2 %. The geo-climatic regions had an important influence on the inventory because emissions varied among regions, with the dry and tropical sub-humid geo-climatic regions being the highest CH₄ emitters due to their larger cattle populations and the effect of climate on cattle diets’ quality, and in turn, the effect of diet on CH₄ emission. The IPAs associated with dry matter intake(DMI) and gross energy intake (GEI) of cattle considerably impacted the uncertainty of enteric CH₄ emission estimates. This study concludes that implementing a bottom-up Tier 2 approach using disaggregated AD and country-specific EF allows a more accurate inventory estimation and assessment of its uncertainty than existing inventories. Future efforts to improve the quality of CH₄ inventories must focus on improving the accuracy of AD, like DMI, GEI, and country-specific EF.

Cite this article

Angeles-Hernandez, J. C., Ku-Vera, J. C., Vázquez-Carrillo, M. F., Castelán-Jaime, S. V., Molina, L. T., Benaouda, M., Kebreab, E., González-Ronquillo, M., Paz-Pellat, F., Montelongo-Pérez, H. D., & Castelán-Ortega, O. A. (2024). Analysis of spatially distributed enteric methane emissions from cattle across the geo-climatic regions of Mexico and uncertainty assessment. Atmospheric Environment, 322, 120389. https://doi.org/10.1016/j.atmosenv.2024.120389