Leapfrogging an outdated standard puts India on par with global leaders in control of vehicle emissions

On September 16, 2016 the Government of India took an important step towards addressing the country’s severe air pollution problems with the final notification of Bharat Stage (BS) VI emission standards for motor vehicles. With this action, India will leapfrog directly from current BS IV standards to BS VI, bypassing the ineffective Stage V level. The BS VI standards will be implemented beginning in April 2020 and are comprehensive in scope. They address all major vehicle types and include provisions that will ensure clean fuels are available alongside the introduction of new, low-emitting vehicles.

The leapfrog to BS VI is a big deal for India. Motor vehicles play an important role in air quality challenges currently facing the country, particularly in urban areas. The implementation of BS VI will largely align Indian emission standards with Euro 6/VI regulations in place in the European Union. This is an ambitious target, and extensive actions will be required of auto manufacturers, fuel suppliers, and other stakeholders over the next 3 to 4 years. The Indian public will benefit greatly from these efforts and the implementation of BS VI in 2020.

From a public health perspective, the most important advance is the new particulate matter emission limits for diesel vehicles. A recent assessment by the Global Burden of Disease Study estimates that 586,787 premature deaths in India were attributable to fine particulate (PM2.5) pollution in 2013. The BS VI standards greatly reduce allowable emissions of PM2.5 from current standards and introduce new limits on the number of particles that can be emitted from these vehicles. These requirements, combined with the parallel introduction of ultra-low sulfur fuels, will lead to the widespread adoption of diesel particulate filters, which can nearly eliminate PM2.5 emissions from diesel vehicles.

To get a clear understanding of the air quality and human health benefits of BS VI implementation, consider a likely scenario of what will happen to PM2.5 emissions from vehicles in India between 2020 and 2050 assuming full implementation of BS VI, compared to business-as-usual (which is BS IV). As the chart shows, in both scenarios emissions of PM2.5 grow between 2020 and 2050, because the Indian motor vehicle fleet will itself grow in size, particularly heavy-duty vehicles. But the adoption of BS VI standards in 2020 will offset some of the negative air pollution and human health consequences of this growth. We estimate that the adoption of BS VI will result in 2.3 million tonnes of avoided PM2.5 emissions between 2020 and 2050. To put this into perspective, the PM2.5 emissions reductions in 2050 alone (130,000 tonnes) are close to the estimated emissions from the entire Indian motor vehicle fleet in 2020 (140,000 tonnes). In the 2020-2050 timeframe, emissions of black carbon (a major component of PM2.5 emitted by diesel vehicles) would be 1.5 million tonnes less under BS VI than under business as usual. The human health and climate benefits will be enormous.

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Effect of BS VI implementation on PM2.5 emissions and premature mortality in India

These emissions reductions will lead to significant health benefits for the Indian public. Using well-documented methodology, we estimate that about 1.2 million premature deaths are avoided between 2020 and 2050 with the implementation of BS VI emission standards. This is a conservative estimate, as the analysis does not consider the health benefits of reductions of pollutants other than tailpipe PM2.5.

The benefits of BS VI standards extend beyond PM2.5 reductions. Our review of the draft BS VI notification highlights many of the improvements of BS VI relative to BS IV standards. Also, the Centre for Science and Environment has a nice overview of why the leapfrog to BS VI is such a big step forward for the country.

That’s the good news.

We’d be remiss if we didn’t mention some of the areas in which the final BS VI notification fails to live up to the draft proposal. Several changes were made during the finalization of the BS VI rule which weaken the standard:

  • Light-duty vehicles: Type-approval requirement for Real-Driving Emissions (RDE) testing using portable emissions measurement system (PEMS) will be delayed until 2023. PEMS testing will be required only for data collection purposes from 2020-2023. PEMS testing of vehicles in real-world driving conditions has emerged in Europe as an important regulatory tool to reduce the 7x higher real-world NOx emissions of diesel engines.
  • Heavy-duty vehicles: PEMS testing requirements for type-approval and in-service conformity will be delayed until 2023, with testing for data collection only from 2020-2023. The HDV in-service conformity requirement is one of the key reasons for the success of the HDV Euro VI emission standards. The lack of in-service conformity factors for heavy-duty vehicles between 2020 and 2023 weakens the overall stringency of the BS VI standards for heavy-duty vehicles.
  • Two-wheelers: Durability requirements for certain two-wheeler classes are reduced from 35,000 km to 20,000 km. Higher durability requirements promote more effective emission control systems.
  • Three-wheelers: NOx emissions limits are relaxed relative to the draft notification and the proposed HC limit is replaced with a combined HC+NOx limit. These changes effectively allow higher emissions of NOx, an ozone precursor, from three-wheelers.
  • Fuel specifications: Maximum vapor pressure for commercial gasoline increased from 60 kPa to 67 kPa. Higher vapor pressure gasoline may lead to increased evaporative emissions of volatile organic compounds, an important precursor to ozone formation.

Despite these shortcomings, the BS VI standard positions India amongst the leaders in the global transition to clean fuels and low-emitting vehicles. The adoption of the BS VI regulation is the first instance of a country or region leapfrogging from Euro 4/IV level directly to Euro 6/VI level emission standards. This step, with the exception of weaknesses noted above, marks a new path forward for all developing country markets to follow to accelerate the adoption of clean vehicle technologies and fuels. Indian regulators and other stakeholders should be congratulated for these accomplishments, with the recognition that much hard work lies ahead in order to ensure the ambitious goals outlined in the BS VI emission norms are realized.