Sierra Leone's Sources of N2O Emissions
Key Insights
Agriculture Drives The Story
In Sierra Leone, N2O emissions are dominated by agriculture, accounting for roughly three-quarters of the total and only a small share of the country's overall greenhouse warming impact (a bit over 2%). Emissions were very low and steady through the early and mid‑20th century, followed by a brief post‑war rise and then a long plateau into the late 1990s. Since the turn of the century, agriculture has trended upward, reaching around 1.2 megatonnes in recent years-the highest on record.
Non-Agricultural Emissions Remain Modest
Energy-related N2O rose gently from the 1960s to about 0.1 megatonnes and has edged down slightly since the early 2010s, indicating a leveling pattern. Other sources increased from the late 1960s through the 2000s to roughly 0.15 megatonnes before easing to around 0.1. Waste has climbed slowly but steadily from near-zero to roughly 0.07 megatonnes by the 2020s. Industry is negligible throughout.
Current Trajectory And Focus
Today's picture shows rising agriculture as the principal driver, while energy appears stable to slightly declining and other sources have softened. With agriculture, energy, and other each above 5% of N2O emissions, progress hinges on reversing the agricultural rise and maintaining or accelerating the stabilization seen in energy and other. Waste remains a smaller but gradually growing contribution that merits monitoring.
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.