Sri Lanka's Sources of N2O Emissions
Key Insights
Agriculture Dominates The Picture
Sri Lanka's N2O profile is led by agriculture, making up about three-quarters of emissions. After relatively steady levels through the early 20th century, agriculture rose from the late 1950s, accelerating into the 2000s and peaking just over 2 megatonnes in the early 2010s. Since then, emissions have reversed course, declining to around 1.2 megatonnes by the early 2020s, signaling a meaningful but recent downturn.
Non-Agricultural Sources Evolve Gradually
Energy climbed gradually from negligible levels through the 1970s to roughly 0.35 megatonnes, then leveled off and edged down slightly after the mid-2010s. Waste shows a steady long-run rise, reaching about 0.27 megatonnes today. The "other" category increased through the 1990s and early 2000s to around 0.25 megatonnes, then eased toward roughly 0.20 megatonnes. Industry has remained near zero throughout. Cumulatively since 1850, agriculture has contributed roughly 150 megatonnes, with energy and "other" around 20 each, and waste near 10.
Outlook And Near-Term Priorities
Today, the largest sources are moving in different directions: agriculture is trending downward, energy appears to be stabilizing or slightly falling, and the "other" category is easing, while waste continues to rise. Keeping agriculture on a sustained decline and consolidating plateaus in energy and other will matter most, alongside curbing the ongoing growth in waste to prevent it from eroding recent gains.
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.