It's difficult to convey how oppressive Delhi's air pollution is.

Key points: New Delhi's count of harmful PM2.5 particles exceeds a staggering 1,000

New Delhi's count of harmful PM2.5 particles exceeds a staggering 1,000 The highest rating is reserved for readings between 300 and 500

The highest rating is reserved for readings between 300 and 500 Millions of tweets, Facebook and WhatsApp posts express people's collective frustration

Morning visibility is a couple of hundred metres. Through the eerie filtered light, figures emerge from and disappear into the gloom.

Some wear masks or handkerchiefs, most blithely dismiss the apocalyptic atmosphere, shrugging it off as "just fog".

Except it isn't.

Last Wednesday, central New Delhi's count of harmful PM2.5 particles exceeded a staggering 1,000 on the US EPA's air quality index.

To put that in perspective, the highest rating, "hazardous to human health — do not go outside", is reserved for readings between 300 and 500.

Delhi was off the scale, twice.

The concentration of poisonous particles is so intense that ingesting it, even through a mask, blurs the line between taste and smell. Eyes water. Throats rasp.

"But, if China can fix this, then tell me, why can't we!?" demanded one news anchor angrily, of an unfortunate live studio guest.

Sadly, the interrogation wasn't aimed at a politician, but instead an environmental activist wondering the same thing.

"Its a very good question," the activist replied.

Outrage rarely outlasts social media posts

Following angry protests several years ago, Chinese Premier Li Keqiang declared "war" on pollution, fearing worsening air could spark wider community unrest.

He ordered crackdowns on factories and power plants flouting rarely-enforced regulations.

According to Greenpeace, it's working.

Last year, the environmental group examined a decade of satellite particulate matter measurements, concluding "China's systematic efforts to combat air pollution have achieved an impressive improvement in average air quality".

India generally dislikes comparisons to rival China, and Greenpeace's findings didn't make for happy reading in Delhi.

"From 2011 to 2015, China has made big strides while in India, pollution levels have kept rising," the report noted.

Why? Because Delhiites' seasonal outrage rarely outlasts their social media posts, and the country's politicians know it.

In the last week, millions of tweets, Facebook and WhatsApp posts tagged #DelhiChokes and #airpocalypse have expressed people's collective frustration — a year after record-breaking pollution prompted Government promises of action in 2016 — the same thing is now happening again.

But not only is the digital mobocracy's rage ephemeral, it is also quickly diluted by a myriad of rival interests.

Take the ham-fisted effort to replicate an initiative used in China and elsewhere — only allowing private vehicles on alternate days.

The scheme was to take effect this week, but the Delhi state administration shelved it over the weekend, irritated that India's environmental tribunal ruled there would be no exceptions for women, motorbikes or senior Government workers.

In Delhi, illegal stubble burning, a widely-acknowledged contributor to the seasonal smog, continues. ( Reuters: Cathal McNaughton )

Health is not a major concern

Meanwhile in states surrounding Delhi, illegal stubble burning, a widely-acknowledged contributor to the seasonal smog, continues.

Politicians in Punjab, Haryana and Uttar Pradesh say poor farmers have no alternative.

Punjab's chief minister argued that penalising farmers would be "more criminal" than "the act for which they are being condemned".

Similar pleas are made by transport, construction, brick-making and other industry sectors, all complaining that regulation or forced change would be an impossible imposition on ordinary Indians.

The gridlock provides an easy excuse for politicians to do nothing.

Indeed, India's Twitter-loving Prime Minister Narendra Modi hasn't mentioned it once. Indifference is bliss.

And there's another reason this 'weather the storm' approach works too.

Unlike in China, where anger spurred Beijing into action, air quality and its impact on health simply isn't a major concern for many Indians, especially poorer ones.

Numerous working-class Delhiites say their lungs are "used to it", or if they do concede ill-health, they'll question the cause.

The indifference to their health exasperates doctors like lung surgeon Dr Arvind Kumar.

"Their lungs are turning black," Dr Kumar, chairman of lung surgery at New Delhi's Ganga Ram hospital, said.

"We're going to have an epidemic of lung cancer."

So, what must come first, anger or leadership?

Some wear masks or handkerchiefs, most blithely dismiss the apocalyptic atmosphere, shrugging it off as 'just fog.' ( Reuters: Saumya Khandelwal )

People's movement could bring change

Mexico's ambassador to India last week wrote how contingency plans for various pollution levels built awareness and support for Mexico City's efforts to curb pollution in the 90s.

Something similar does exist in New Delhi, but requires little action in all but the most extreme circumstances.

Ambassador Melba Maria Pria Olavarrieta argued that Mexico City's graded directives gave the pollution issue "a direct impact on the lives of the common man, woman, boy and girl".

The disruption, she said "created awareness and dialogue about the importance of air quality".

Considered the world's most polluted city in 1992, Mexico City's example also refutes the argument that such change is impossible in developing countries.

Would it work in Delhi?

Dr Kumar thinks it will take a public push, like the kind that drove change in China.

"The Communist Party there saw it as an issue which could affect the survival of the Government, so they reacted," he said.

That sort of concern has so far been lacking or temporary in India, but Dr Kumar is hopeful that with sustained pressure it will come.

"When it becomes a people's movement in India too, the Government will have no choice but to sit up and act on it," he said.

It's a cruel irony. Fear of public anger is credited with driving change in a one-party state, while the citizens of a great democracy argue amongst themselves.