Sao Tome and Principe's Sources of N2O Emissions
Key Insights
Long-Term Low, Recent Rise
Sao Tome and Principe's nitrous oxide emissions stayed very low from the early record through the late 20th century, with only minor movement. Since the 1990s, totals have trended upward at a steady pace, remaining small in absolute terms (on the order of hundredths of a megatonne per year) but clearly increasing in climate impact.
Agriculture Dominates The Trend
Agriculture accounts for about three-fifths of national N2O emissions and sets the overall pattern. After a long period of near‑stable, low emissions through the post‑war era, agricultural emissions have climbed since the early 1990s, reaching around 0.01 Mt in recent years. The rise has been gradual rather than volatile, but it marks a several‑fold increase from earlier levels.
Energy, Other, And Waste Growing
Non‑agricultural sources are smaller individually but have also edged up. Energy-related emissions have risen slowly since the late 1970s, with a modest uptick in the late 2010s to roughly 0.004 Mt. "Other" sources have moved upward since the 1980s to a similar level, while waste has increased more modestly since the late 1990s to around 0.002 Mt. Industry remains negligible.
Current Trajectory And Priorities
Most major sources-agriculture, energy, other, and waste-are on a rising path. Reversing the upward trend in agriculture should be the top priority, while stabilizing or slowing growth in energy and other sources, and containing waste-related increases, would help bend the overall trajectory.
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.