Canada's Sources of N2O Emissions
Key Insights
Long-Run Rise In Agriculture
Canada's nitrous oxide profile has been shaped mainly by agriculture, contributing about two-thirds of national N2O. From the late 1930s through the early 1980s emissions climbed quickly, then kept rising more gradually into the 2000s, landing in the mid-30s megatonnes by the early 2020s. Over the full record, agriculture has added roughly 2,300 megatonnes, dominating the cumulative total and the overall climate impact from N2O.
Industry Down, Energy Easing
Industrial N2O was modest until the post-war era, surged through the 1960s and 1970s to the mid-teens megatonnes, then declined steadily from around 1980 to low single digits today-a major and sustained reversal. Energy-related emissions rose gradually from mid-century, reached the mid-2000s at around 4 megatonnes, and have edged down slightly since, remaining near that level. "Other" sources have been relatively stable since the 1990s, fluctuating around 3 megatonnes, while waste is a minimal share.
Current Trajectory And Priorities
Among sources that matter most, agriculture is still trending upward and remains the dominant driver; bending this curve is essential. Industry has been falling for decades-clear progress to maintain-while energy shows a gentle decline that likely needs to accelerate to shift the total. "Other" sources are broadly stable to slightly lower. Overall, gains outside agriculture have not yet offset the agricultural rise, so Canada's N2O trajectory will depend most on changes in that largest sector.
Background
The chart shows a national breakdown by source of the yearly nitrous oxide (N2O) emissions from human activities and processes, expressed as weight in megatonnes (Mt). Human-induced emissions are the main driver of the increasing atmospheric nitrous oxide that is warming our planet. The sources of human nitrous oxide emissions are
- Agriculture
- Energy
- Industry
- Waste
- Other
Agriculture
Emissions related to agriculture are mainly from the use of synthetic fertilizers and manure management.
Synthetic fertilizer, used for agricultural processes, contains a lot of nitrogen. That nitrogen in the soil reacts and causes considerable N2O emissions. The use of excess fertilizer, meaning more fertilizer than the plants can use to grow, causes even higher relative emissions. Applying the right amount of fertilizer at the right time can reduce N2O emissions. There are many technical solutions to reduce emissions while keeping, or even increasing, agricultural yields.
When manure is left on the field or otherwise managed in dry processes, it emits considerable amounts of nitrous oxide. Manure can be managed by wet processes, which reduces nitrous oxide emissions but increases methane emissions. Some technical solutions focus on modifying the animal feed to reduce the nitrogen in the manure, thereby reducing nitrous oxide emissions.
Energy, Industry, Waste, and Other
All non-agricultural categories together have much lower emissions than agricultural emissions alone.
N2O emissions related to energy are almost all from the combustion of fossil fuels. For example, the combustion of fossil fuels in power plants, cars, and airplanes not only causes CO2 emissions but also emits nitrous oxide (N2O). Any advances to reducing fossil fuel dependency will thus also reduce nitrous oxide emissions.
Most industry-related emissions are from the chemical industry for producing fertilizer, nylon, and similar products. Technologies are available to reduce emissions in these processes.
Nitrous oxide emissions from waste come from, for example, wastewater treatment and landfills.
Wikipedia: Nitrous oxideIPCC: AR6, 5.16 Anthropogenic nitrous oxide (N2O) emissions
Units and Measures
N2O emissions are expressed in the total weight in megatonnes per year. 1 Megatonne is equal to 1 million tonnes.
Wikipedia: MegatonneWikipedia: Global warming potential
About the Data
The last available year in all the emission datasets is 2023. N2O emissions come from the PRIMAP-Hist dataset. It is a rich dataset that combines several published sources to create a historical emissions time series for various greenhouse gases.
The Key Insights paragraph was created using a large language model (LLM) in combination with our data, historic events, and a structured approach for best accuracy by separating the context generation from the interpretation and narrative.
Data Sources
PRIMAP-hist The PRIMAP-hist national historical emissions time series (1750-2023)
Update cycle: Every few monthsDelay: Less than 1 yearCredits: Gütschow, Johannes; Busch, Daniel; Pflüger, Mika (2024): The PRIMAP-hist national historical emissions time series (1750-2023) v2.6. Zenodo.