Integrating Income-Stratified Dietary Transitions into the AFOLU_India Model: Implications for Fertiliser Use and N₂O Emissions in India

Rapid income growth and structural transformation in India are reshaping dietary patterns, with important implications for nutrition, agricultural systems, and climate mitigation. Targeting developed-nation status by 2047 under the Viksit Bharat vision, the country faces acute trade-offs between meeting growing nutritional needs and containing agricultural greenhouse gas (GHG) emissions, particularly from nitrogen fertilizer use.

Existing integrated assessment models (IAMs) have limited capacity to capture income-disaggregated, nutrition-sensitive demand dynamics particularly for rapidly developing economies like India. This study addresses that gap using HCES data across five income groups, projecting food demand under two GDP growth trajectories: a BAU Scenario and a Sustainable Diet Scenario aligned with the Viksit Bharat 2047 target (per capita GDP ~$18,000) and national nutrition policies including Mission LiFE and POSHAN Abhiyaan.

Results show divergent dietary pathways. The BAU Scenario sees continued cereal-heavy demand with limited diversification, while the Sustainable Diet Scenario stabilises cereal consumption and significantly expands nutrient-dense foods pulses, vegetables, fruits, and milk. Total food demand rises from 476 MT (2024) to 661 MT (BAU) and 853 MT (Sustainable Diet Scenario) by 2050.

Production requirements are linked to nitrogen fertilizer use and N₂O emissions via the AFOLU-B model. Despite higher output under the Sustainable Diet Scenario, fertilizer efficiency gains and manure substitution partially decouple emissions from production growth (145 vs. 160 MtCO₂e by 2050, a ~10% difference). The findings demonstrate that sustainable dietary transitions can deliver substantial nutritional gains with manageable emission trade-offs, underscoring the need to integrate income-heterogeneous, demand-side dynamics into IAM frameworks and climate policy.