From Smog to Solutions: Mapping a Cost-Effective Path to Clean Air in Hanoi by 2030

The World Bank's 2022 report reveals that Hanoi faces dangerously high levels of PM2.5 pollution, largely from industrial, transport, and agricultural sources, much of it from outside the city. Despite new policies, only coordinated, multi-sectoral action combined with climate measures can bring air quality within safe limits by 2030.

The World Bank report “Clean Air for Hanoi: What Will it Take?” presents a detailed, multidisciplinary analysis of air pollution in Vietnam’s capital and surrounding provinces. Conducted in partnership with international and national research institutes, including the International Institute for Applied Systems Analysis (IIASA), the Finnish Meteorological Institute (FMI), the Asian Institute of Technology (AIT), Vietnam’s Research Center for Environmental Monitoring and Modelling (CEMM), and RCEE-NIRAS, the study utilizes cutting-edge emissions modeling and field data to unravel the scale, sources, and impacts of Hanoi’s air quality crisis. The picture it paints is troubling: millions of residents are exposed daily to unsafe levels of fine particulate matter (PM2.5), with current policies falling short of protecting public health.

Choking on Progress: The Cost of Economic Growth

While Vietnam has made admirable strides in economic development and poverty reduction, these gains have been accompanied by a sharp increase in environmental degradation. Nowhere is this more evident than in Hanoi and its neighboring provinces, Bac Ninh and Hung Yen. Using the GAINS (Greenhouse gas–Air pollution Interactions and Synergies) model, researchers calculated that in 2015, PM2.5 concentrations across the region exceeded both national ambient air quality standards (25 µg/m³) and the World Health Organization guideline (10 µg/m³). Over 3.5 million people, nearly 40% of the region's population, were exposed to concentrations above 45 µg/m³, nearly five times higher than the WHO’s recommended threshold.

A startling finding was that only one-third of the air pollution in Hanoi originates within the city itself. The rest is transported from neighboring provinces, elsewhere in Vietnam, and even from other countries. Local contributors include transportation (25%), industrial activity including emissions from Hanoi’s famous craft villages (35%), residential combustion (10%), agriculture via ammonia emissions (20%), and the open burning of waste (around 7%). These figures underscore the complexity of Hanoi’s air pollution problem and the urgent need for inter-regional coordination.

The Limits of Current Policies: A Dangerous Trajectory

Despite new policies introduced after 2021, the study’s modeling suggests they are insufficient to curb worsening air quality. Under the “policies before 2020” scenario, essentially business as usual, PM2.5 concentrations could climb to nearly 60 µg/m³ by 2030. These alarming levels would put every resident in Hanoi, Bac Ninh, and Hung Yen at risk, with exposure to pollution levels five to six times the WHO guideline.

Even with newer regulations that promote energy efficiency and enforce emissions limits more strictly, projections show that over 70% of Hanoi’s population will still live in areas where PM2.5 levels exceed 45 µg/m³. The reduction, while notable, is far from enough. Without additional interventions, the policies alone will not bring Hanoi close to meeting national air quality targets.

Co-Benefits of Climate Action: A Glimmer of Hope

However, when climate commitments from Vietnam’s 2020 Nationally Determined Contributions (NDCs) are layered on top of existing policies, the trajectory changes. Incorporating climate-aligned strategies such as reducing coal dependency, transitioning to renewable energy, curbing ammonia emissions through better agricultural practices, and electrifying transport fleets significantly improves projected air quality.

Under this combined approach, PM2.5 levels across most of the region could fall below 35 µg/m³, and exposure to the most dangerous pollution zones would decrease substantially. Yet even this integrated policy mix would leave only a small share of the population living in areas that meet the national standard. The findings point to a sobering reality: more ambitious, targeted action is needed.

Mapping the Way Forward: Cost-Effective Solutions and Global Lessons

Using the optimization mode of the GAINS model, researchers identified a cost-effective strategy for achieving compliance with Vietnam’s air quality standards by 2030. This “least-cost” approach balances financial feasibility with technical potential and prioritizes interventions that provide the highest return on investment. Key measures include strengthening emission standards for power plants, deploying high-efficiency particulate filters, banning open agricultural burning, tightening vehicle emissions standards, and promoting public transport and electric mobility.

Marginal abatement cost curves developed for Hanoi demonstrate that replacing motorbikes and cars with electric vehicles and installing waste heat recovery systems in industry are among the most financially efficient interventions. In the transport sector alone, these measures could reduce thousands of tons of PM2.5 at relatively low or even negative net costs.

Yet the report stresses that no matter how cost-effective the solution, Hanoi cannot solve the problem alone. The transboundary nature of air pollution demands regional cooperation. Establishing a coordinated air quality management mechanism among Hanoi, Bac Ninh, and Hung Yen, and ideally extending across the Red River Delta, is essential. Lessons from cities like Beijing, London, and Jakarta illustrate how coordinated policy, strong enforcement, and public investment can rapidly turn the tide on urban air pollution.

The report ends with a clear call to action. Vietnam has the tools, data, and international experience to reduce its urban air pollution and protect the health of its people. What’s needed now is the political will and institutional coordination to act. If implemented swiftly and decisively, the measures outlined in this study could not only make Hanoi’s air breathable again but also position Vietnam as a regional leader in sustainable urban development.