Residents of Delhi will have a new rule to follow on the roads in the New Year. In a controversial and bold Beijing-style move to try and improve the city's horrible air pollution, the last number of a car's license plate will determine on what days it can be driven.
Access to city's roads will alternate between license plates ending in odd or even numbers, with all automobiles permitted on Sundays.
Soon after the government of Delhi announced the new rules, the country's Supreme Court imposed a moratorium on registering new vehicles with large diesel engines in Delhi until the end of March. It also prohibited trucks that are older than 10 years old from the city.
Angel Hsu, the director of the Yale Data-Driven Environmental Solutions Group and an assistant professor at the Yale School of Forestry and Environmental Studies, has studied the air quality in both Beijing and New Delhi.
"It's definitely one of the world's most polluted cities by many measures," Hsu said of Delhi.
One metric of air quality is referred to as PM 2.5, which is particulate matter that is 2.5 micrometers or smaller. Those intrusive, miniscule particles pose both respiratory and cardiovascular risks for people. The World Health Organization (WHO) says the upper limit for PM 2.5 concentration, averaged over a year, is 10 micrograms per cubic meter.
Delhi's levels are way over that guideline. On average, the concentration of PM 2.5 in Delhi is between 130 to 150, and since November 1 of this year, it's averaged between 250 to 300. Pollution levels generally worsen in the winter, due to factors like temperature inversions — when cold, dense air sinks below warmer air — and increased burning of materials like leaves, for warmth.
In fact, in 2014, when the WHO reported pollution levels in over 1500 cities around the world, Delhi had the worst PM 2.5 concentration, with an average of 153 in 2013. Particulate matter pollution in the city comes from sources like construction, vehicles, diesel generators, and the burning of waste.
"One thing that I found quite surprising is withinNew Delhi, they still allow a lot of open burning," Hsu said. "That was something that I found very viscerally arresting about the air pollution in New Delhi versus China."
Hsu said the odd-even license plate rule has worked well for Beijing, even if the city's pollution has recently gotten so bad the government imposed its first ever "red alert," which brought about school closures and restrictions on traffic and manufacturers.
"When Beijing implemented the odd-even rule for the first time around the Olympics, the results were dramatic," Hsu said. Since then, the rule has remained, and other measures, like improving the subway infrastructure,imposing a lottery system to determine who can get a license, and relocating landfills out of the city limits, have also helped, she said.
"I think that implementing the same [odd-even] rule in India is definitely a huge start," Hsu said. She added that the city should boost vehicular fuel standards and get dirty diesel vehicles off the streets, too.
Arunabha Ghosh, the chief executive officer of the Council on Energy, Environment, and Water, a New Delhi policy research organization, said that the city's air quality "has been steadily deteriorating" for the past five years, and that in the winter, the pollution "poses significant health risks."
"The government's policy to restrict driving will have some positive impact in reducing the pollution," Ghosh said. "However, the [amount] of reduction that will be achieved remains a matter for further study." He said that in order to make the policy sustainable, the city needed to take measures to improve public transportation and boost security for women.
"While taking steps to reduce vehicular pollution is a good starting point, they may not prove enough," Ghosh added. Ultimately, he said, in order for India to meet its own air quality standards, there will need to be better government coordination, as well as measures to reduce other pollution sources, like emissions from thermal power plants and crop burning.
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