Emissions of the third most prevalent climate-damaging greenhouse gas, nitrous oxide (N20), have surged by some 40% in the past 40 years, according to a new study.
The analysis carried out by the Global Project research network, led by Boston College in the US, found that the levels were particularly high in the most recently analysed years of 2020 and 2021.
The gas is commonly used in medical settings as an anaesthetic dubbed laughing gas.
However, much larger quantities of emissions are produced unintentionally, such as during the fertilization of fields or the burning of fossil fuels, and consequently enter the atmosphere.
According to the study, agriculture is responsible for 74% of human nitrous oxide emissions.
N20 emissions increased significantly over the past four decades in countries experiencing rapid population growth, such as China and India. In contrast, emissions in Europe decreased, largely due to reduced fossil fuel usage and changes in the chemical industry's processes, according to the researchers.
Lead author Hanqin Tian from Boston College emphasized that reducing nitrous oxide emissions is crucial for meeting climate targets and limiting global warming to 2 degrees Celsius.
"Reducing nitrous oxide emissions is the only solution, as there are currently no technologies available to remove nitrous oxide from the atmosphere," he said.
Experts recommend using fertilizers more efficiently to reduce the amount of N20 emissions.
The US Environmental Protection Agency, for example, recommends reducing the use of oil, gas and coal or using catalytic converters when burning them.
According to Tian, this is the most comprehensive study of global nitrous oxide to date, involving 58 experts from 15 countries.