Global Agricultural Greenhouse Gas Emissions: Direct Fertilizer-Based Emissions

Growing environmental, social, and political pressures has driven the development of policies surrounding emission reductions. Nitrous oxide, a potent greenhouse gas, is emitted predominantly by the agricultural sector, most of which is associated with crop production. 

Canada’s Strengthened Climate Plan, redefined Canadian emission targets under the Paris Agreement, targeting the agricultural sector specifically to reduce fertilizer-based emissions. The methodology to measure N2O emissions varies according to the International Panel on Climate Change (IPCC) varies, depending on the use of a Tier 1, 2 or 3 approach, increasing data inclusion and resolution with Tiers. With the current methodology in place, farmers have limited potential to reduce N2O emissions, as mitigation strategies predominantly hinge on impractical and inaccessible options, such as reducing fertilizer application or changing location. Based on the current measures, Canadian emissions are high relative to other major production regions. A model across IPCC Annex I parties adjusting for average wheat yield as a benchmark and incorporating fertilizer application rate for different countries demonstrated low-efficiency and yield in Canada. Multiple scenarios are tested to determine how an improved Canadian efficiency measure, use of a disaggregated emission factors, and a combination of both, would influence the model and benchmark values. 

Improving the methodology to measure N2O emissions would improve measurement accuracy and support development of emission reduction policies for farmers to implement within operations.

By Joshua Bourassa, Elena Vinco

Keywords: Emission Reduction, IPCC, Fertilizer, Nitrous Oxide, Greenhouse Gas

Published March 31, 2022.