Greenhouse gas emissions from nitrogen fertilisers could be reduced by up to one-fifth of current levels by 2050 with combined interventions

Abstract

Food security relies on nitrogen fertilisers, but its production and use account for approximately 5% of global greenhouse gas (GHG) emissions. Meeting climate change targets requires the identification and prioritisation of interventions across the whole lifecycle of fertilisers. Here, we have mapped the global flows of synthetic nitrogen fertilisers and manure, and their corresponding GHG emissions across their lifecycle. We have then explored the maximum mitigation potential of various interventions to reduce emissions by 2050. We found that approximately two thirds of fertiliser emissions take place after their deployment in croplands. Increasing nitrogen use efficiency is the single most effective strategy to reduce emissions. Yet, this should be combined with decarbonisation of fertiliser production. Using currently available technologies, GHG emissions of fertilisers could be reduced up to approximately one fifth of current levels by 2050.