Researchers call for a ‘full-scale rethink’ about the way in which nitrogen fertilisers are used around the world.
The growing use of nitrogen fertilisers for food production worldwide is increasing the atmospheric concentration of nitrous oxide and jeopardising the climate goals of the 2015 Paris Agreement.
This is the conclusion arising from a study carried out by an international group of researchers from 48 institutions in 14 countries, including the UK’s University of East Anglia. The work has been published in the journal Nature. The study was led by Auburn University, Alabama, US, under the umbrella of the Global Carbon Project and the International Nitrogen Initiative.
The study points to what the researchers call an ‘alarming trend,’ affecting climate change; with nitrous oxide having risen 20 percent from pre-industrial levels. The fastest growth has been observed in the last 50 years due to emissions from human activities. Nitrous oxide is greenhouse 300 time more potent the carbon dioxide.
The researchers added that their findings also indicated an ‘emerging nitrous oxide-climate ‘feedback’ resulting from interactions between nitrogen added to crops for food production and global warming, further enhancing emissions derived from agriculture.’
The Study found that the largest contributors to global nitrous oxide emissions come from East Asia, South Asia and South America. Emissions from synthetic fertilisers dominate releases in China, India and the US. Emissions from application of livestock manure as fertiliser dominate nitrous oxide release in Africa and South America. The highest growth rates for emissions come from the emerging economies of Brazil, China and India in particular.
However, the agricultural and the chemical sectors in Europe have seen a decrease in nitrous oxide emissions. The researchers say that this is due to several factors including voluntary measures to remove nitrous oxide from flue gases in the nylon industry and the introduction of an emissions trading scheme as well as more efficient use of fertiliser to reduce environmental impacts.
Lead UK author Dr Parvadha Suntharalingam from University of East Anglia’s School of Environmental Sciences said ‘The analysis identifies the factors driving the steadily increasing levels of N2O and highlights the urgent need to develop effective mitigation strategies if we are to limit global warming and meet climate goals.’
DOI:10.1038/s41586-020-2780-0
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