The rapidly increasing use of nitrogen fertilizers for enhancing food crop production is posing an imminent threat of uncontrollable Nitrous Oxide (N2O) concentration in the atmosphere. N2O is a potent greenhouse gas, which has a global warming potential 300 times more than carbon dioxide, and remains accumulated in the atmosphere for more than an average human lifespan.
A recent study published in Nature, conducted at Auburn University, USA, by a team of 57 researchers from 14 countries, aimed at comprehensively analyzing all the global sources and sinks of N2O gas. The International Institute for Applied Systems Analysis (IIASA) was the major contributing research body, and the study was undertaken as part of the Global Carbon Project and the International Nitrogen Initiative. The results depict an alarming rise in the concentration of N2O, significantly contributing towards global climate change. Researchers analyzed a 20% increase in N2O emissions when compared with the pre-industrial state i.e. from 270 parts per billion (ppb) in 1750 to 331 ppb in 2018. Furthermore, the last half century has been regarded as the period with the fastest increase in N2O levels, owing to various human activities.
Prof. Hanqin Tian, director of the International Center for Climate and Global Change Research at Auburn University’s School of Forestry and Wildlife Sciences, stated, “the dominant driver of the increase in atmospheric nitrous oxide comes from agriculture, and the growing demand for food and feed for animals will further increase global nitrous oxide emissions. There is a conflict between the way we are feeding people and stabilizing the climate.”
The research also unveils an apparent N2O-climate ‘feedback’ caused due the interaction between the use of nitrogen fertilizers for food production and resultant global warming which further enhances the share of greenhouse gases’ emissions by the agriculture sector. East Asia, South Asia, Africa and South America have been identified as the major contributors to N2O emissions. In China, India and USA, the application of artificial fertilizers while in Africa and South America, the use of animal manure as fertilizer, is regarded as the major source of N2O release. However, the agriculture and chemical sector in Europe depicted a noticeable decrease in N2O emissions. This has been attributed to various factors like voluntary efforts to remove N2O from flue gasses in the Nylon industry, development of emission trading initiatives and sustainable use of fertilizers to reduce water pollution.
The executive director of the Global Carbon Project, Josep “Pep” Canadell, said, “This new analysis calls for a full-scale rethink in the ways we use and abuse nitrogen fertilizers globally and urges us to adopt more sustainable practices in the way we produce food, including the reduction of food waste.”