Thesis (B.S.) -- Cagayan State University, 2025.

This study conducts a carbon emission inventory and Logarithmic Mean Divisia Index (LMDI) decomposition analysis of CO₂ emissions in Tuguegarao City's road transport sector from 2021 to 2024. Amid rapid urbanization and post-COVID recovery, the research quantifies emissions by vehicle type, identifies dominant drivers, and formulates policy recommendations to support sustainable transport. Using secondary data from the Department of Energy (DOE), Land Transportation Office (LTO), and Intergovernmental Panel on Climate Change (IPCC), emissions were estimated at 37,261 tCO₂ in 2021, rising to 106,322 tCO₂ in 2024. Utility vehicles (UVs) dominated at 43.81%, followed by trucks (22.05%) and tricycles (17.16%).

The LMDI results show that fuel intensity was the strongest contributor to the increase in emissions, accounting for 54.2% of the total change. This reflects high average fuel consumption per vehicle, particularly among diesel-powered utility vehicles and trucks. The Activity Effect contributed 45.8%, driven by rapid growth in registered vehicles. No significant fuel structure shifts were observed, indicating that emission increases were due to efficiency and activity changes rather than alterations in fuel type.

The study recommends strengthening fuel-efficiency standards, enhancing emission testing and compliance for aging vehicles, incentivizing electric and low-carbon vehicle adoption, and modernizing public and para-transit systems. Improved data integration between agencies is also necessary to support evidence-based planning. These measures collectively aim to reduce fuel intensity and promote sustainable, low-carbon mobility for Tuguegarao City.

Keywords: CO₂ emissions, LMDI decomposition, road transport, Tuguegarao City, Philippines.