In the last few days, three far-reaching news flashes, the establishment of overarching air quality commission in the NCR, IPCC reporting 1.0°C of global warming above pre-industrial level, and vehicle scrapping policy, share national and global concerns. And transport sector has a causal linkage to the news flashes and well-being of humans and the earth.
Of estimated 17,090 kilotons per year of fine particulate matter (PM 2.5 ) emission in the country, the transport sector emits only 2%, and as for greenhouse gases, about 7.5%. While the triviality of the figures may not warrant attention, their health and climate impacts should.
A recent study on cancer potential source apportionment for Delhi city revealed that diesel combustion from older in-use vehicles and DG sets ranks on top, disproportionate to their emissions. The contribution of the transport sector to breathing level PM 2.5 air quality varies from 20-35% in urban centres. The GHG emission from the transport sector in urban areas can well be above 30%.
The transport sector at the urban level contributes over 50% of the total NOx and 10% of the non-methane hydrocarbon, responsible for the formation of ozone and secondary organic PM 2.5 through complex atmospheric chemistry.
The original equipment manufacturers (OEMs) and the governments across the world have made strides in the abatement of automotive emissions and the efforts continue. In India, the improvements in automobile technology and fuel efficiency and a quick climb to the Bharat Stage (BS)-VI emission standards are evidentiary of our commitments.
Consequently, the PM emissions will be similar both for gasoline and diesel vehicles. Our refineries and OEMs have achieved monumental feat within a short span at comparable efficiencies as their international counterparts. India has joined the league of the USA, Japan, and the European Union (EU) by fast-forwarding enforcement of the BS-VI norms. But the finish line is far from here.
The visible impact of BS-VI vehicles will be apparent after 2025 when sizeable numbers of old vehicles are replaced. The impact of the vehicle scrapping policy to boost new BS-VI vehicles is yet to be seen. The long-term BS-VI sustenance will require the creation of a smart ecosystem of trained service centres and responsible citizenry.
The new tailpipe control system would be complex and sophisticated that it will be hugely challenging to replace the parts. And an underperforming technology would mean forfeiting the massive investment and the health benefits reckoned. Therefore, measures will be needed to spread education regarding the criticality of continuous and appropriate inspection and regular maintenance of the vehicle.
When a new vehicle comes on the road, the country’s premier Homologation and Testing Centers grant ‘Type Approval Certificate (TAC)’. The certification procedures consist of testing engine performance and emission compliance on the chassis dynamometer in the laboratory following a driving cycle that simulates the driving conditions.
Internationally, the vehicle testing agencies question the driving cycles and laboratory tests if they do truly reflect emissions of real driving conditions. Real driving emission (RDE) on-road tests are becoming mandatory worldwide. Specialized equipment installed on the vehicle exhaust stores emission data to verify that the legislative limits for pollutants are compiled to while the vehicle is driven on the road.
A poor RDE cycle may undo the benefits of BS-VI. The challenge in RDE tests is the trip (speeds, distances, durations, etc.) selection that can offer an RDE driving cycle. The EU has formalized the RDE driving cycle concerning prevalent traffic, road, and physical ambient conditions. The RDE cycle must cleverly account for conditions prevailing in the country such as low and high altitudes, year-round temperatures, and urban, rural roads and highways.
The electric vehicle (EV) can significantly reduce urban air pollution. The pace of adoption of EVs is likely to be gradual and will depend on the vehicle segments and government policies. The barrier of affordability and concerns over charging time, and anxiety over driving ranges, are slowing the expansion of EVs. The time is right to consider lower taxes for batteries.
Till the time battery EVs (BEVs) take over, hybrid electric vehicles (HEVs) that blend fuel and electric power are much more fuel-efficient with an electric driving range of 30-40 kilometers than internal combustion (IC) vehicles. Since HEVs are fuel efficient and do not face the challenges of range anxiety, charging time, and infrastructure, the replacement of new IC engines with HEVs can come about at a much faster pace. Until we move to complete e-mobility, our three main objectives of the transition phase should be to ensure smooth execution of BS-VI norms, develop a justified RDE cycle, and promote cleaner HEVs.
(The author is Professor of Civil Engineering, IIT Kanpur. Views are personal)