Mr. Speaker, with regard to (a), the government’s calculations for nitrous oxide emissions associated with nitrogen fertilizer use are published in the National Greenhouse Gas (GHG) Inventory Report, which is accessible at https://publications.gc.ca/site/eng/9.506002/publication.html.
With regard to (b), the government received data on fertilizer use, in agricultural markets each year, in metric tonnes of nitrogen, and at a provincial scale.
There are no known nationally representative statistics available to the government that track the quantity of nitrogen fertilizers applied on farms. As a result, the provincial fertilizer statistics are used as a proxy.
With regard to (i) of part (c), the government uses methodologies consistent with the 2006 guidelines from the Intergovernmental Panel on Climate Change, or IPCC, that use, for the most part, country-specific parameters derived from Canadian research as reported in the National GHG Inventory Report.
A detailed description of the methodology is available in Annex 3.4, section A3.4.5, in Part 2 of the 1990-2021 National Inventory Report. Nitrogen from organic and inorganic sources are distributed to the landscape according to the procedure described at the beginning of section A3.4.5.
Regarding direct emissions, the current approach is based on three Canadian scientific publications, namely Liang et al. 2020; Rochette et al. 2018; and Pelster et al. 2022, which summarize the research that has been carried out in Canada over the past 30 years. A base Emission Factor, or EF, for growing season and non-growing season nitrous oxide emissions is established for areas of Canada that have a unique combination of climate, landscape and soils, called ecodistricts considering multiple factors including the topography of the cropland, moisture regimes, precipitation, potential evapotranspiration, and soil texture, all of which influence how much nitrous oxide is emitted when fertilizer is applied. These base EFs are then further adjusted with factors to account for the nitrogen source, cropping system, tillage and irrigation, which are additional factors that relate to how farmers manage the land that further impact the amount of nitrous oxide that is emitted to the atmosphere.
As for indirect emissions, these are estimated from volatilization and redeposition of nitrogen, and leaching and runoff losses.
A country-specific method was used to estimate ammonia emissions from inorganic nitrogen application. This approach derives ammonia emission factors based on the type of inorganic nitrogen fertilizers, the degree of incorporation into soil, crop type and soil chemical properties.
For leaching and runoff losses, a modified IPCC Tier 1 methodology is used to estimate nitrous oxide emissions from leaching and runoff of inorganic and organic nitrogen fertilizers, and crop residue nitrogen from agricultural soils. The fraction of nitrogen leached from the soil is determined for each ecodistrict and varies from 0.05 to 0.3, depending on the climatic characteristics of the region.
More details on specific equations used in the direct and indirect emission calculations are published in the National Inventory Report Annex 3.4, ECCC, 2023.
With regard to (ii) of part (c), the agriculture sector’s share of emissions are calculated based on the results reported in the National GHG Inventory Report. The fraction is based on the quantity of emissions coming from the agricultural sector, which are reported in Chapter 6 of the National Inventory Report, relative to the total sum of all nitrous oxide emissions coming from all sectors in the inventory report.
In 2021, the agricultural sector emitted 54 megatonnes of carbon dioxide equivalent, or 8.1% of Canada’s total emissions, which are 670 megatonnes of carbon dioxide equivalent. Nitrous oxide emissions from agricultural soils were 19 megatonnes in 2021, making up 35% of the emissions from the agricultural sector. Nitrous oxide emissions increased from 15 megatonnes in 1990 to 23 megatonnes in 2021, representing an increase of 52%.
In 2021, nitrous oxide emissions from agriculture, or 23 megatonnes of carbon dioxide equivalent, contributed to 75% of Canada’s total nitrous oxide emissions, or 30 megatonnes of carbon dioxide equivalent. The contribution of agricultural nitrous oxide to national nitrous oxide emissions rose from 43% in 1990 to 75% in 2021.
With regard to (d), the fertilizer target was developed based on scientific literature and internal analysis that points to the potential for optimizing nitrogen fertilizer use with an accompanying reduction in greenhouse gas emissions, while maintaining or increasing yield. The reduction percentage of 30% was the result of an iterative process weighting various factors and characteristics, such as: ambitious, considering climate goals and international efforts; technically achievable, given that the technologies and know-how largely exist; economically feasible, given potential cost savings and increased yield through efficiency gains and better management; and scientifically defensible, given that it is supported by research findings relevant to Canadian context.