Empirical Assessment of Solid Waste Management Scenarios and Greenhouse Gas Emission Implications in Kano State

This study empirically assesses the greenhouse gas emission implications of current and alternative solid waste management scenarios in Kano State, North West Nigeria, filling the gap in waste-sector climate accounting evidence needed to support Nigeria's NDC implementation in the waste sector. Waste management contributes significantly to global greenhouse gas emissions primarily through methane generated in uncontrolled landfills and open dumpsites, and Nigeria's waste management trajectory has significant implications for its ability to meet climate commitments. Current waste generation, composition, and disposal practices in Kano were characterised through a waste audit of the main disposal sites and a household waste generation survey covering 350 households across six residential zones. The IPCC Tier 1 and Tier 2 first-order decay methods were applied to estimate methane emissions from existing disposal sites. Life cycle greenhouse gas accounting was conducted for five alternative management scenarios including increased recycling, composting, anaerobic digestion, sanitary landfill with gas capture, and refuse-derived fuel. Uncertainty analysis was performed using Monte Carlo simulation. Results indicate that current practice generates approximately 180,000 tonnes of carbon dioxide equivalent annually from Kano State's waste sector. The landfill-with-gas-capture scenario reduces emissions by 62 percent relative to the baseline, while an integrated scenario combining source separation, composting, and landfill with gas capture achieves an 81 percent reduction. Economic co-benefits from compost and energy sales enhance the financial case for integrated scenarios. The study provides evidence for Kano State's climate action planning. Keywords: greenhouse gas emissions, solid waste management, climate change, methane, Kano State.