Nitrous oxide emissions, harmful to the climate, are increasing exponentially.
The gas Lachgas comes in as the third leading greenhouse gas, trailing behind CO2 and methane. A recently published study shows the rise in emissions of this climate-harming gas has been quite significant since 1980. Researchers are urging for a reduction in these emissions to help us achieve our climate goals.
Human activities are responsible for most of the nitrous oxide (also known as N2O in the scientific world) production. Whilst some Lachgas occurs naturally, two-thirds of the current emissions can be credited to us humans. The last few years, 2020 and 2021 to be exact, have seen particularly high values.
Nitrous oxide is utilized as an anesthetic by healthcare professionals. But, much more of it is released unintentionally, through agricultural practices or through burning fossil fuels resulting in contamination of the atmosphere.
Principal contributors: chemical fertilizer and animal waste
Both natural and anthropogenic nitrous oxide enter the atmosphere, but the latter's impact is greater. Humans have tampered with the Earth's natural nitrogen cycle. They convert atmospheric nitrogen (N2, not N2O) into fertilizers via a chemical process. Furthermore, there's livestock bringing about manure left in meadows or distributed on fields.
If this fertilizer fails to be completely absorbed by the plants, it could either directly convert into nitrous oxide or end up in the atmosphere at a later stage. Based on the detailed study, agriculture is now responsible for 74% of human-caused nitrous oxide emissions.
In countries such as China and India, where the population has grown exponentially, nitrous oxide emissions have significantly increased. Europe, on the contrary, has witnessed a decrease in emissions, possibly due to less fossil fuel consumption and a transformation within the chemical industry's processes.
Nearly 25% more Lachgas in our air
In the years 2020 and 2021, ten million tons of nitrous oxide were emitted annually by humans. Before industrialization, there were only 270 nitrous oxide molecules per billion molecules (ppb) in the atmosphere in 1750. This has now grown to 336 molecules by 2022, a heady increase of almost 25%.
The head researcher of this study, Hanqin Tian from Boston College, emphasizes the necessity of lowering nitrous oxide emissions to achieve their climate targets. "The reduction of nitrous oxide emissions is the only solution, as there are currently no technologies available to extract nitrous oxide from the atmosphere," he stated. "The reduction of nitrous oxide emissions is the only solution, as there are currently no technologies available to extract nitrous oxide from the atmosphere."
Lowering emissions with more effective fertilization
To reduce the production of human-created nitrous oxide, several measures are being proposed. The EPA (United States Environment Protection Agency) considers it paramount to use fertilizers more efficiently: If less fertilizer is employed, there will be less of it left over in the soil, which can convert into nitrous oxide.
Additionally, the agency recommends using less oil, gas, and coal, and implementing catalysts while combusting these resources. An extensive research undertaking was conducted by 58 experts from 15 nations, including Europe. Through this, they collected millions of measurements from four decades spanning from the atmosphere, freshwater, and oceans. In Tian's words, this is the most extensive research on the global greenhouse gas nitrous oxide (N2O) to date.
However, due to the uncertainty regarding the soil properties, the authors provide a broad range of N2O emissions. Nevertheless, the measurements of N2O content in the atmosphere are quite accurate.
