Singapore Transport Air Pollution Profile 2026
SINGAPORE
TRANSPORT AIR POLLUTION PROFILE
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Background
Singapore, a high-income economy in Southeast Asia with a population of 5.8 million and a GDP per capita of $155,972 in 2024, has made notable progress in reducing air pollution over recent decades. The annual average concentration of particulate matter (PM 2.5), weighted by population exposure, declined from 21.1 micrograms per cubic meter in 2000 to 15.1 micrograms per cubic meter in 2023. While this represents significant improvement and remains below the WHO interim target of 25 micrograms per cubic meter, it still exceeds the WHO air quality guideline of 5 micrograms per cubic meter. For context, Southeast Asia's regional average stood at 20.2 micrograms per cubic meter in 2022, placing Singapore in a relatively favorable position within the region.
The transport sector plays a substantial role in Singapore's air pollution profile. According to the State of Global Air, transport and international shipping contributed approximately 18.5% and 3.1% to ambient PM 2.5 concentrations respectively in 2019. The urban spatial distribution of pollution exposure presents additional concerns—the Institute for Transportation and Development Policy estimates that only 19% of Singapore's urban population lives beyond 500 meters from highways, meaning the vast majority of residents face proximity-related exposure to vehicular emissions.
The health consequences of air pollution exposure remain significant despite improvements in air quality. World Bank estimates indicate that 1,331 people died prematurely due to exposure to ambient PM 2.5 in 2019. McDuffie and colleagues (2021) estimate that approximately 293 of these premature deaths could be directly attributed to transport tailpipe emissions. Additionally, occupational exposure to diesel engine exhausts resulted in at least five premature deaths in 2023, equivalent to less than one death per million population. The economic toll of these health impacts is substantial—the World Bank estimated that health damages from ambient and household PM 2.5 exposure cost Singapore approximately $14.0 billion in 2019, representing about 2% of GDP. This proportion, while concerning, compares favorably to the Asia-Pacific average of 10.6% of GDP. For reference, Singapore allocated 4.9% of its GDP to healthcare expenditure in 2022.
Singapore's economic growth has been accompanied by mixed trends in transport-related emissions. Since 2010, the nation's GDP has grown at an impressive 6.4% annually, while emissions from the transport sector have shown divergent patterns across different time periods. PM 2.5 emissions from transport increased by 4.4% between 2000 and 2010 but subsequently declined by 5.3% between 2010 and 2022, suggesting that policy interventions and technological improvements have begun to decouple economic growth from transport pollution. Emissions from other sectors have grown more modestly, at 0.5% per year since 2010. By 2022, the transport sector accounted for 28% of Singapore's total PM 2.5 emissions.
The modal composition of transport emissions reveals distinct patterns. In 2022, PM 2.5 emissions from transport were distributed as follows: 43% from road transport (including non-exhaust emissions), 57% from domestic navigation, and negligible contributions from rail and domestic aviation. The road transport share increased from 37% in 2010 to 43% by 2022. Within the road sector, the International Institute for Applied Systems Analysis (IIASA) estimates that heavy-duty vehicles dominate PM 2.5 emissions, contributing 91% in 2025, with light-duty vehicles, motorcycles, and buses accounting for 5%, 2%, and 2% respectively. Meanwhile, the share of navigation decreased from 63% in 2010 to 57% by 2022, with large vessels contributing 99% and medium vessels 1% of navigation-related PM 2.5 emissions. Notably, non-exhaust emissions from resuspended dust, brake wear, and tire wear have become increasingly significant, rising from 19% of road sector emissions in 2010 to 29% by 2022.
Nitrogen oxide (NOx) emissions from transport showed similar trends, growing by 1.8% between 2000 and 2010 before declining by 3.6% between 2010 and 2022. Other sectors saw NOx emissions decline by 0.3% annually since 2010. By 2022, transport accounted for 36% of total NOx emissions in Singapore. The modal breakdown for transport NOx emissions in 2022 comprised 78% from road, 22% from domestic navigation, and negligible shares from rail and aviation. Road transport's proportion increased from 70% in 2010 to 78% by 2022, with IIASA estimating that heavy-duty vehicles contributed 92% of road sector NOx emissions in 2025, followed by light-duty vehicles at 6% and buses at 2%. For domestic navigation, large vessels accounted for 94% and medium vessels for 6% of NOx emissions.
Sulfur oxide (SOx) emissions from transport experienced the most dramatic changes, growing by 28.2% between 2000 and 2010 before declining by 6.1% between 2010 and 2022. Other sectors saw SOx emissions plummet by 8.0% annually since 2010. By 2022, transport represented 10% of total SOx emissions, with domestic navigation accounting for virtually all transport-related SOx (100% in 2022, up from 99% in 2010), while road transport's minimal contribution declined from 1% to essentially zero over the same period.
Emissions of other pollutants also trended downward. Methane (CH4) emissions from transport declined by 0.5% between 2000 and 2010 and by 3.0% between 2010 and 2022, with the road sector accounting for 97% of transport CH4 emissions by 2022. Non-methane volatile organic compounds (NMVOC) from transport fell by 4.7% between 2000 and 2010 and by 3.7% between 2010 and 2022, again with road transport contributing 97% by 2022. Black carbon (BC) emissions decreased by 0.7% between 2000 and 2010 and by 5.6% between 2010 and 2022. In 2022, BC emissions from transport comprised 59% from road (including non-exhaust sources) and 41% from domestic navigation, with road's share rising from 56% in 2010.
The transport sector's energy consumption profile reflects Singapore's ongoing but gradual transition toward cleaner energy sources. In 2023, the road sector dominated transport energy consumption at 84%, with rail, domestic navigation, and domestic aviation contributing 11%, 5%, and less than 1% respectively. Oil products accounted for 89% of transport sector energy consumption in 2023, showing a modest decline from 92% in 2010 and 93% in 2015. Biofuels remained virtually absent at less than 1% of the energy mix, while electricity's share reached 11% by 2023.
Singapore's electricity grid emission factor stood at 499 grams of CO2 per kilowatt-hour in 2024, comparing favorably to the Asia-Pacific average of 559 and Southeast Asia's 583. However, the pace of grid decarbonization has been relatively modest, with Singapore achieving a 0.2% annual improvement since 2015, slower than the Asia-Pacific region's 1.4% annual improvement rate. The persistence of fossil fuel subsidies carries additional external costs for Singaporean society, with 43% of these costs manifesting as increased local air pollution.
Singapore has witnessed substantial growth in electric vehicle adoption in recent years. Between 2017 and 2024, the value of electric vehicle imports reached $3.1 billion, representing 34% of total road vehicle imports by 2024. The composition of these imports heavily favors light-duty vehicles at 95%, with goods vehicles and buses comprising 4%, and two-wheelers representing less than 1%. The United Nations Environment Programme's E-mobility Readiness Index assigns Singapore a score of 81 out of 100, with component scores of 13 for technology and market development, 25 for policy frameworks, 21 for energy infrastructure, and 22 for financial instruments.
Despite being a wealthy, densely populated city-state, Singapore's motorization rate has actually declined slightly, from 178 vehicles per thousand population in 2000 to 169 in 2024. This stands in stark contrast to the Asia-Pacific average of 317 vehicles per thousand population in 2024, reflecting Singapore's long-standing policies to manage vehicle ownership and use through economic instruments and public transport investment. The nation has expanded its rapid transit infrastructure substantially, increasing from 34.2 kilometers of rapid transit per million urban population in 2015 to 40.0 kilometers by 2024. Public transport accessibility appears near-universal—among Singapore's urban agglomerations, 100% achieve an access level of 50% or better, meaning at least half the population resides within 500 meters of public transport.
Air Quality
Air Pollution from Transport
Health Burden
Resuspended Dust, Brake, and Tyre-wear
Vehicle Fuel Mix
Vehicle Fleet
Policy Landscape
Ban of ICE sales
| EV Policy | Not Found | All new car registrations will have to be of cleaner-energy models from 2030. Cleaner-energy models include electric, hybrid or hydrogen fuel cell cars. We will also stop new diesel car registrations from 2025. | 2025 |
| Second Update of First Nationally Determined Contribution | Not Found | phase out internal combustion engine vehicles by 2040 | 2040 |
| Singapore Green Plan | Not Found | New registrations of diesel cars and taxis to cease from 2025 | 2025 |
| Singapore Green Plan | Not Found | All new car and taxi registrations to be of cleaner-energy models from 2030 | 2030 |
| Singapore's Long-Term Low-Emissions Development Strategy | Not Found | We aim to phase out internal combustion engine vehicles by 2040, and have all vehicles running on cleaner energy. | 2040 |
| SINGAPORE'S SECOND NATIONALLY DETERMINED CONTRIBUTION (NDC) | Not Found | We remain committed to phasing out pure internal combustion engine vehicles by 2040 | 2040 |
| Singapore's Fifth National Communication and Fifth Biennial Update Report | Not Found | Singapore is working on the large-scale adoption of green vehicles. By 2040, we aim to phase out internal combustion engines and have all vehicles running on cleaner energy | 2040 |
| Voluntary National Reviews 2023 - SGP | Not Found | No new diesel car registrations from 2025, and no new internal combustion engine car registrations from 2030; | 2025 |
| Voluntary National Reviews 2023 - SGP | Not Found | No new diesel car registrations from 2025, and no new internal combustion engine car registrations from 2030; | 2030 |
| Singapore Country Report | 2023 | Phase out ICEs and have all vehicles run on cleaner energy | 2040 |
| Singapore's Adaptation Communication | 2022 | By 2040, we aim to phase out internal combustion engines and have all vehicles running on cleaner energy | 2040 |
EV in public transport
| Singapore Country Report | 2023 | Electric buses make up half of public bus fleet | 2030 |
EV mandates/ procurement
| EV Policy | Not Found | We have started by deploying 60 electric buses and will replace 400 diesel buses with electric buses by 2025. With these 60 electric buses, the CO2 tailpipe emissions from buses will decrease by approximately 7,840 tons annually. | 2025 |
| EV Policy | Not Found | Our taxi fleet operators have also set targets to electrify their fleet, by committing at least half of the total taxi fleet to go electric by 2030. | 2030 |
| EV Policy | Not Found | The Singapore Green Plan 2030 includes a strong push to electrify our vehicle population, which would help Singapore achieve our vision of 100% cleaner energy vehicles by 2040. | 2040 |
| Singapore Green Plan | Not Found | Electric buses to make up half of the public bus fleet by 2030. Existing diesel buses will be replaced with cleaner energy buses by 2040 | 2030 |
| Singapore Green Plan | Not Found | All vehicles to run on cleaner energy by 2040 | 2040 |
| Singapore Country Report | 2023 | All new car and taxi registrations to be of cleaner-energy models | 2030 |
| Singapore Country Report | 2023 | Phase out ICEs and have all vehicles run on cleaner energy | 2040 |
| Singapore's Adaptation Communication | 2022 | By 2040, we aim to phase out internal combustion engines and have all vehicles running on cleaner energy | 2040 |
| Extension And Adjustments To Commercial Vehicle Emissions Scheme And Early Turnover Scheme | 2022 | Government's vision to have all vehicles run on cleaner energy by 2040 | 2040 |
Port electrification
| Singapore Green Plan | Not Found | All new harbour craft operating in our port waters to be fully electric, be capable of using B100 biofuels, or be compatible with net zero fuels from 2030 | 2030 |
Shipping fuels
| Maritime Singapore Decarbonisation Blueprint | Not Found | By 2030, MPA aims to reduce absolute emissions from the domestic harbour craft fleet by 15% from 2021 levels, through the adoption of lower-carbon energy solutions such as blended biofuel, LNG, diesel-electric hybrid propulsion, and full-electric propulsion. | 2030 |
| Singapore Green Plan | Not Found | All new harbour craft operating in our port waters to be fully electric, be capable of using B100 biofuels, or be compatible with net zero fuels from 2030 | 2030 |
Vehicle scrappage scheme
| Singapore Green Plan | Not Found | Electric buses to make up half of the public bus fleet by 2030. Existing diesel buses will be replaced with cleaner energy buses by 2040 | 2040 |
References
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