New Zealand's Sources of N2O Emissions
Key Insights
Agricultural Dominance in Emissions
New Zealand's nitrous oxide (N₂O) emissions have been predominantly driven by agriculture, a trend that has persisted for over a century. The introduction of synthetic fertilizers around 1960 significantly increased N₂O emissions, as these fertilizers became a staple in agricultural practices. The agricultural sector's contribution to N₂O emissions has consistently been the largest, accounting for the vast majority of the country's total N₂O output. This dominance is reflected in the decadal data, where agriculture consistently represents the highest percentage of total N₂O emissions.
Energy and Industrial Shifts
While agriculture remains the primary source of N₂O emissions, energy and industrial activities have also contributed to the overall emissions profile. The 1973 oil crisis led to a shift in energy sources, increasing the use of domestic coal and natural gas, which impacted emissions. The opening of the Tasman Pulp and Paper Mill in 1953 and the introduction of synthetic fertilizers in 1960 further contributed to industrial and energy-related emissions. These sectors, although smaller in comparison to agriculture, have shown gradual increases in their share of emissions over the decades.
Policy and Environmental Impact
New Zealand's policy initiatives, such as the introduction of the Emissions Trading Scheme in 2008 and the Zero Carbon Bill in 2017, have aimed to address greenhouse gas emissions across various sectors. These policies reflect the country's commitment to reducing its carbon footprint and mitigating climate change. The agricultural emissions pricing plan announced in 2021 specifically targets methane and N₂O emissions, highlighting the importance of addressing agricultural emissions in New Zealand's overall climate strategy. These efforts underscore the country's proactive approach to managing its unique emissions profile.
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 generated using a large language model (LLM) using a structured approach to improve the accuracy. This included 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.