Unlike organic fertilisers, which come from plant or animal material, synthetic fertilisers are made by humans using chemical processes.
Production and transportation cause carbon emissions, while agricultural use of these fertilisers leads to the release of nitrous oxide (N₂O) – a greenhouse gas 265 times more potent than carbon dioxide (CO₂) over a century.
The research team – from the Greenpeace Research Laboratories at the University of Exeter, and the University of Turin – found that the synthetic nitrogen fertiliser supply chain was responsible for emitting the equivalent of 1.13 gigatonnes of CO₂ in 2018.
This is more than 10% of global emissions from agriculture, and more than the emissions from commercial aviation in that year.
The top four emitters – China, India, USA and the EU28 (European Union countries plus the UK) – accounted for 62% of the total.
Read more at: University of Exeter
Crops being treated with nitrogen fertiliser in Beauce, France (Photo Credit: Emile Loreaux / Greenpeace)