Decarbonization in dualistic economies: Evidence from a subnational mitigation portfolio in a rural Andean province, Peru

Subnational climate action is increasingly recognized as essential for achieving national mitigation targets, yet localized greenhouse gas inventories and economically viable mitigation portfolios remain limited for rural regions of the Global South. This study analyzes decarbonization pathways in a dualistic subnational economy by developing the first comprehensive greenhouse gas inventory for the province of Chachapoyas, Peru, and evaluating sectoral mitigation strategies through an ex-ante cost–benefit framework. Emissions were estimated using IPCC Tier 2 methodologies for the agriculture, energy, and solid waste sectors, with all conversions based on 100-year Global Warming Potential values from the IPCC Sixth Assessment Report (AR6: CH₄ = 27.9; N₂O = 273). Total baseline emissions reach 239,035 tCO₂e per year, with agriculture accounting for 88.4% of the provincial total. Enteric fermentation from 115,845 cattle represents the dominant source, contributing 187,800 tCO₂e yr⁻¹ (78.5%). Electricity consumption and municipal solid waste generate 9913 tCO₂e yr⁻¹ and 13,313 tCO₂e yr⁻¹, respectively. The mitigation analysis reveals distinct economic and temporal dynamics across sectors: LED lighting retrofits provide the fastest financial return (7.5 month payback), silvopastoral systems offer the largest mitigation potential (up to 75,480 tCO₂e yr⁻¹), and organic waste composting achieves the lowest abatement cost (USD 0.39 per tCO₂e over a ten-year horizon). These findings highlight the importance of diversified mitigation portfolios that combine rapid-return technological interventions with longer-term agricultural transformations. The results provide actionable evidence for subnational climate planning and position Chachapoyas as a representative case for designing mitigation strategies in intermediate Andean regions characterized by agricultural dominance and emerging urban environmental pressures.