Prioritizing greenhouse gas emission mitigation measures for agriculture

Since the signing of the Kyoto protocol, a major effort has been launched in Canada to identify cost-effective measures to reduce greenhouse gas (GHG) emissions. Agriculture is an important contributor of methane and nitrous oxide in Canada. Over one-third of methane and almost four-fifths of nitrous oxide emissions are from agriculture either directly or indirectly. By 2010 primary agricultural production is expected to generate about 67 megatonne (in carbon dioxide equivalent), which increases to 97 megatonnes if all activities related to agricultural production are considered. Based on a systems approach, nutrient management was selected as a possible scenario for mitigation. Estimated results indicate that this could lead to a reduction of 0.9 megatonnes of GHG emissions at the primary agricultural production level, and 1.2 megatonnes if the total agriculture and food sectors are included. Compared to the direct emissions (from fertilizer rate and timing of application), the systems approach suggests up to a doubling (from 0.4 to 0.92 Mt) of this reduction potential at the primary production level. If one were to include emissions from the entire agriculture and agri-food system, potential of up to tripling (from 0.4 to 1.23 Mt) the reduction of GHG can be achieved. The need of a systems approach in prioritizing measures to reduce GHG emissions is supported by this study.