Nitrogen Fertilizers and Climate Change: A Comprehensive Review of Greenhouse Gas Emissions and Sustainable Management

Greenhouse gases (GHGs) such as carbon dioxide (CO₂), methane (CH₄), nitrous oxide (N₂O), water vapor, fluorinated gases and ozone play a pivotal role in global warming by trapping heat in the Earth's atmosphere. Among these, N₂O is particularly potent, with a global warming potential approximately 273 times that of CO₂ over a 100-year period. Agriculture contributes significantly to anthropogenic GHG emissions, accounting for approximately 12% globally. A substantial portion of these emissions arises from the production and application of synthetic fertilizers, which have been instrumental in boosting global food production. The manufacture of synthetic nitrogen fertilizers is energy-intensive, leading to considerable CO₂ emissions. Upon application, these fertilizers can result in N₂O emissions due to microbial processes in the soil. Studies estimate that synthetic nitrogen fertilizer use accounts for about 8.3% of farm-gate emissions. Projections suggest that, without intervention, agricultural GHG emissions could reach 8–9 gigatonnes of CO₂-equivalent per year by 2050. The impact of fertilizer application on GHG emissions is therefore a major environmental concern, demanding targeted policy and agronomic interventions. Overapplication and inefficient nitrogen use not only contribute to climate change but also pose risks to soil and water health. Addressing these challenges requires a balance between maximizing crop yields and minimizing environmental harm. Mitigation strategies include optimizing fertilizer application rates, adopting precision agriculture techniques, and integrating organic fertilizers. Such practices can reduce N₂O emissions and enhance nitrogen use efficiency. Transitioning to sustainable fertilizer management is crucial for minimizing agriculture's climate impact while ensuring food security.