Malaysia, an upper-middle-income economy in Southeast Asia with a population of 35.6 million and a GDP (PPP) of $1.4 trillion in 2024, has made notable progress in reducing ambient air pollution concentrations over the past two decades. The annual average population-weighted concentration of PM 2.5 declined from 22.6 micrograms per cubic meter in 2000 to 15.9 micrograms per cubic meter in 2023, reflecting a significant improvement in air quality. While this 2023 level remains below the World Health Organization's interim target of 25 micrograms per cubic meter, it continues to exceed the WHO air quality guideline of 5 micrograms per cubic meter by a considerable margin. The country's performance compares favorably to the regional average, as Southeast Asia recorded an average concentration of 20.2 micrograms per cubic meter in 2022.

The health consequences of air pollution exposure in Malaysia impose substantial mortality and economic costs on the population. The World Bank estimates that 10,551 premature deaths occurred in 2019 due to ambient PM 2.5 exposure, with transport tailpipe emissions specifically contributing approximately 2,059 premature deaths according to McDuffie et al. (2021). Occupational exposure to diesel engine exhausts resulted in at least 113 premature deaths in 2023, equivalent to approximately 3 deaths per million population. The economic burden of ambient and household PM 2.5 exposure reached 36.6 billion USD in 2019, representing about 4 percent of Malaysia's GDP—a figure that appears modest when compared to the Asia-Pacific regional average of 10.6 percent of GDP, yet remains higher than Malaysia's healthcare expenditure of 3.9 percent of GDP in 2022. These health impacts are exacerbated by urban planning patterns, as the Institute for Transportation and Development Policy estimates that only 38 percent of Malaysia's urban population lives beyond 500 meters from highways, leaving the majority potentially exposed to elevated concentrations of traffic-related pollutants.

The transport sector has become an increasingly significant contributor to Malaysia's air pollution profile, despite the country's economic growth trajectory of 6.2 percent annually since 2010. PM 2.5 emissions from transport declined by 4.2 percent between 2000 and 2010, but this trend reversed with a 2.3 percent growth rate between 2010 and 2022, while emissions from other sectors grew more modestly at 0.9 percent annually during the latter period. By 2022, the transport sector accounted for 27 percent of total PM 2.5 emissions in Malaysia. The State of Global Air estimates that transport and international shipping contributed approximately 16.9 percent and 2.6 percent, respectively, to ambient PM 2.5 in 2019. Road transport dominates the sector's emissions profile, representing 100 percent of transport PM 2.5 emissions by 2022—an increase from 97 percent in 2010—while domestic navigation's contribution declined from 2 percent to negligible levels during the same period. Heavy-duty vehicles constitute the primary source within the road sector, with IIASA estimating that they account for 70 percent of PM 2.5 emissions in 2025, followed by light-duty vehicles at 21 percent, motorcycles at 7 percent, and buses at 3 percent.

Malaysia's transport sector generates a complex mixture of air pollutants, each following distinct emission trajectories that reflect changes in vehicle technology, fuel quality, and fleet composition. Nitrogen oxide (NOx) emissions from transport declined by 2.2 percent between 2000 and 2010 before growing by 2.9 percent between 2010 and 2022, with the sector responsible for 44 percent of total NOx emissions by 2022. Road transport accounts for 99 percent of transport NOx emissions, with heavy-duty vehicles generating 73 percent of road sector NOx in 2025, according to IIASA estimates. Sulfur oxide (SOx) emissions from transport have declined consistently, falling by 10.5 percent between 2000 and 2010 and by 10.7 percent between 2010 and 2022, though the transport sector's contribution to total SOx emissions remains negligible at less than 1 percent. Black carbon (BC) emissions from transport declined by 5.8 percent between 2000 and 2010 but subsequently grew by 1.3 percent between 2010 and 2022, with road transport accounting for 100 percent of transport BC emissions by 2022. Non-exhaust emissions—including resuspended dust and brake and tire wear—have grown in relative importance, contributing 35 percent of road sector PM 2.5 emissions by 2022, up from 27 percent in 2010.

The transport sector's energy profile in Malaysia remains heavily dependent on fossil fuels, despite modest progress toward diversification. In 2023, the road sector contributed approximately 97 percent of total transport energy consumption, while rail, domestic navigation, and domestic aviation accounted for negligible shares except for aviation at 3 percent. Oil products constituted 94 percent of transport sector energy consumption in 2023, representing a decline from 98 percent in 2010 and 97 percent in 2015, while biofuels and electricity accounted for 5 percent and less than 1 percent, respectively. Electricity consumption in the rail sector has remained stable at approximately 100 percent since 2010. Malaysia's grid emission factor stood at 604 grams of CO2 per kilowatt-hour in 2024—higher than both the Asia-Pacific average of 559 and the Southeast Asian average of 583—with an annual improvement rate of 1.1 percent since 2015, lagging behind the Asia-Pacific improvement rate of 1.4 percent. Fossil fuel subsidies in the transport sector escalated from approximately 15.5 billion USD between 2010 and 2015 to 24.4 billion USD between 2016 and 2023, with Noll et al. (2026) estimating that around 8 percent of Malaysia's total government revenue is generated by fossil fuel taxation.

Malaysia exhibits exceptionally high motorization rates that significantly influence transport emissions and air quality outcomes. Vehicle ownership reached 909 vehicles per thousand population in 2024, substantially exceeding the 2000 level of 816 and dramatically surpassing the Asia-Pacific average of 317 vehicles per thousand population. The value of electric vehicle imports reached 2.3 billion USD between 2017 and 2024, representing 28 percent of total road vehicle imports by 2024, with light-duty vehicles comprising 98 percent of EV imports, two-wheelers 1 percent, and goods vehicles and buses negligible shares. The United Nations Environment Programme's E-mobility Readiness Index assigns Malaysia a score of 81 out of 100, with component scores of 20 for technology and market, 15 for policy, 21 for energy, and 25 for financial instruments. Public transport infrastructure development has been uneven, with rapid transit coverage increasing from 4.7 kilometers per million urban population in 2015 to 11.0 kilometers by 2024. However, accessibility remains severely limited across Malaysia's 37 urban agglomerations, with only 16 percent achieving an access level of 50 percent or better—meaning half of the population within 500 meters of public transport. In 41 percent of cities, eight out of ten residents lack convenient access to public transport, reinforcing automobile dependence and contributing to sustained transport emissions growth.

EV in public transport

EV mandates/ procurement

Vehicle air pollution emission standards

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