Global Agricultural Greenhouse Gas Emissions: Enteric Methane

Efforts to reduce emissions across sectors are implemented globally, as increasing environmental, social, and economic pressures accumulate. The Global Methane Pledge, an agreement between over 100 different countries including the USA and EU, commits to limiting average global temperature increase to ≤ 1.5 degrees. Parties committed to the pledge are required to disclose national methane emissions following IPCC guidelines. 

High variability in emission estimates and calculation methodology for enteric methane produced by cattle in the agricultural sector confound comparability between countries and previous reports. Depending on use of Tier 1, 2, 3 approaches and default emission factors covering different animal, ration, management, and environmental dimensions, emission factors uncertainty values ranged from ±6 to ±50 percent. As the specificity and resolution of data increases as countries move from Tier 1 to Tier 2 and Tier 3 approaches, the resulting emission factors should increase in accuracy, accordingly, reflecting regional and country-specific operations. 

Relative to the other Annex I Parties to the United Nation Framework Convention on Climate Change, average methane emission per head of dairy cattle in Canada is high, linked to increased animal weight and milk productivity. Conversely, average non-dairy cattle emission per head in Canada is low, and is ranked the lowest among major global producers.

By Joshua Bourassa, Elena Vinco

Keywords: Enteric Fermentation, Methane, National Inventory Report Greenhouse Gas Emissions, Agriculture

Published March 31, 2022.