A dynamic model for CO2 emissions induced by urban transportation during 2005-2030, a case study of Mashhad, Iran

The urban transportation sector in Iran handles high fuel consumption and CO2 emission. The research motivation was the investigation of urban transportation to estimate present and future emissions, find the comparative and quantitative outcomes, and cluster the influential variables. Hence, the main aim of the research was to provide a model framework to estimate the urban transpiration effects on the fuel consumption, CO2 emission, and air pollution concentration in Mashhad city (2005-2030) besides producing the mitigation measures on two national emission scenarios. A dynamic model was used based on the multiple intersections among variables and different subsystems to explain the vehicle-based fuel consumptions and induced equivalent-CO2 emissions. The results revealed an increasing trend for total emission (Gg) from 3791 Gg to 6226 Gg during 2005-2020, induced by urban transportation in Mashhad. The emissions equal to 7227 and 8118 Gg can be predicted for 2025 and 2030 under a national scenario, namely business as usual (BAU). Under shed of a different scenario, namely the sixth strategic development plan (SDP) of Iran, the emission can be prospected equal to 3520 and 2925 Gg for similar time (2025-2030) in Mashhad city. The comparative results revealed the mitigation measures for all model variables, e.g., 5,193 Gg reduction in transportation-induced CO2 emission, in 2030. The financial resource for mitigation target of CO2 emission in the Mashhad, until 2030, estimated as 415 million dollars, which is consistently half part of the financial budget of Mashhad municipality in 2020. Showing three variables of car inventory, fuel consumption, and CO2 emission, as the driving powers of the transportation-induced CO2 emissions, the proposed model suggested reconsidering alternative urban vehicle fleets to mitigate emissions by low-emission vehicles or public plans.

Automated summary

The urban transportation sector in Iran is facing challenges of high fuel consumption and CO2 emission. This research aims to investigate the current and future emissions, compare and quantify the outcomes, and cluster the influential factors in urban transportation. A dynamic model is used to estimate the effects of urban transportation on fuel consumption, CO2 emission, and air pollution concentration in Mashhad city. The results show an increasing trend in emissions, with potential mitigation measures identified. The proposed model suggests considering alternative urban vehicle fleets to reduce emissions.