Assessing the Environmental Sustainability of Urban Transport Systems in Kano: A Carbon Footprint Analysis

Urban transport systems are among the largest sources of greenhouse gas emissions in Nigerian cities, yet carbon footprint assessments of city-level transport systems remain rare in the West African literature. This study conducts a carbon footprint analysis of the urban transport system in Kano Metropolis, the largest city in North West Nigeria, to assess the environmental sustainability of current mobility patterns and evaluate mitigation scenarios. The study employs an activity-based emission factor approach, calculating carbon dioxide equivalent emissions from road transport using vehicle fleet composition data, fuel consumption estimates, and vehicle kilometres travelled derived from traffic counts at 18 points across the city over four seasons. The analysis disaggregates emissions by mode, including private cars, commercial buses, motorcycle taxis, and motorcycles. Results show that Kano's urban transport system emits an estimated 2.8 million tonnes of carbon dioxide equivalent annually, with private cars accounting for 34 percent of emissions despite representing only 22 percent of trips. Motorcycle taxis, while individually low-emitting, aggregate to 18 percent of total transport emissions due to their volume. Three mitigation scenarios are modelled: a BRT introduction scenario, a motorcycle electrification scenario, and a non-motorised transport shift scenario. The BRT scenario offers the greatest emission reduction potential at 19 percent. The study fills a significant gap in transport emission quantification literature for Nigerian cities and provides an evidence base for low-carbon urban mobility planning. Keywords: carbon footprint, urban transport, Kano, greenhouse gas, sustainable mobility.