Traffic air pollution emissions in Qatar: Actual, projections and mitigation

The diesel vehicle count data from the traffic department was used along with the annual traveled distance to calculate the actual emissions for the diesel fleet in Qatar in 2017. The projection of diesel fleet emissions in 2030 was then estimated based on three scenarios: (1) if the fleet growth rate continued at the same rate as per the historical data; (2) if the rate of vehicle count increased by 10% reference to 2017 count; and (3) if there was a decline in the growth rate of vehicle count by 20% since major infrastructure projects shall be accomplished soon. The results show that the annual projected CO₂ emissions amounted to 4171, 1800, and 1750 kt for the three scenarios; respectively. Similarly, the annual projected NOx emissions were about 100, 43, and 42 tons for the three scenarios; respectively. The results showed that if no policy is put in place, there will be around 170,000 diesel vehicles contributing to huge amounts of particulate and gaseous emissions. However, under the current plans for the electrification of 5% of cars and 25% of public buses, a 10% and 5% reduction in CO2 and NOx emissions will be attained, respectively. The impact of public transport bus electrification on this category is not as significant as it could be since the majority of emissions are due to heavy-duty vehicles, which are not impacted by this policy.