[humyum]

Originally Posted by alpha1

The marine sources refers to aerosols that are lifted up from the spray (caused by wind & waves) and blown into the city. Hence, of little importance to our understanding about man made pollution.

Thanks for the entire report. If the esteemed judiciary or committee goes through, the answer to winter pollution is very evident.

I think the more interesting graph is the following one, that should settle the efficacy of banning ancient cars/2 wheelers, and expected improvement (hardly any):

So they want to go after something which is not 1% of the whole bunch, but leave more than half the pie out of any danda because it will involve their inefficiencies.

We truly as a banana republic.

[NomadSK]

Originally Posted by Lalvaz

When we take decisions that impact large populations, it should be based on solid research, and not on speculation.

Well there’s no speculation about it that NOx are having serious ill effects to human beings. There are umpteen studies done. We invest millions of dollars every few years to clean our waste flue gasses for all the obnoxious PM’s by installing catalytic converters or changing processes with the advancement of the available technologies, only under environmental norms. Which is super capex intensive.

Please show me a study which says that NOx is a carcinogen.

You can read this;

LINK

Nitrogen oxides (NOx) have not been classified as a potential carcinogen by the Department of Health and Human Services (DHHS), the International Agency for Research on Cancer (IARC), or the EPA.

Please don’t read some random internet source. Side effects of pollution are far worse in long run than we can think of.

Also, when you burn twice the fuel in a petrol car v/s half the fuel in a diesel car, surely you are releasing more pollutants in the environment. That can't be environmentally friendly either. And as for the particulate filters trapping emissions, where do you think they go when you clean or replace those clogged filters?

Pollutants from petrol cars and diesel cars are mostly different from each other, due to the reason, one goes under combustion and the other detonation. Process is different hence the exhaust fumes have different compostion. Earlier scientists till as late as 2000’s were more concerned for GH gasses and that’s why they promoted diesel over petrol, since petrol gave more GH gases as compared to diesel, till they found out that NOx from diesel is harming humans and their cities more.

Also the PM collected on the DPF filter is burned off over a catalyst bed and ammonia fluid to not create much hazardous gases, that’s why BS-6 is better than the previous versions and other are being banned. Same way you might have seen flaring happening from a gas/oil plant.

Here are some snippets of the studies to bust some misconceptions.

[Hayek]

I think a number of people seem to fail to understand the difference between “pollutants” that cause local health damage and “CO2 emissions” which cause global warming.

There is no doubt that the Diesel cycle is intrinsically more efficient than the Otto cycle used in petrol engines. Hence diesels are more fuel efficient and emit lower CO2 per km. But CO2 emissions are irrelevant as far as air quality is concerned - they are a global problem which will lead to temperature rise - and require solutions that are outside the scope of this thread.

But it is also certain that diesel cars - especially those that are pre BS6 stage 2 - emit far higher levels of particulates and NOX than petrol cars. Hence banning old diesel vehicles in cities (which are most affected by smog and have high populations which would be adversely affected by breathing particulates) makes immense sense. Even much less fuel efficient petrol cars emit less particulates than the most fuel efficient diesel.

However, from a public policy perspective, the government has made an effective promise to car buyers who buy cars that meet emission norms on the day they are purchased that they can keep them for their lifetime (15 years based on the OTT) as long as they are maintained in line with standards that apply to that car. So banning diesel or petrol cars before 15 years amounts to a breach of that promise - and the government should be liable to compensate buyers for the same. When the Right to Property was a fundamental right, this could have been enforced. Unfortunately, it is no longer the case - and property can be seized by following any due process specified in the law - including court orders. So does the Bombay High Court or the government have the right to ban brand new diesel cars overnight despite the loss and breach of promise this implies? In my understand, Yes. Should they do that? No - what would be morally right is to have a buy back program for diesel cars and a restriction on entry of any non BS6 diesel vehicle in cities.

Should petrol vehicles be banned? Since they are less harmful, probably not. Should EVs be encouraged in cities even if fuelled by coal based power? Yes - since they reduce emissions and smog in cities which is where most people live.

[humyum]

Originally Posted by Hayek

I think a number of people seem to fail to understand the difference between “pollutants” that cause local health damage and “CO2 emissions” which cause global warming.

There is no doubt that the Diesel cycle is intrinsically more efficient than the Otto cycle used in petrol engines. Hence diesels are more fuel efficient and emit lower CO2 per km. But CO2 emissions are irrelevant as far as air quality is concerned - they are a global problem which will lead to temperature rise - and require solutions that are outside the scope of this thread.

But it is also certain that diesel cars - especially those that are pre BS6 stage 2 - emit far higher levels of particulates and NOX than petrol cars. Hence banning old diesel vehicles in cities (which are most affected by smog and have high populations which would be adversely affected by breathing particulates) makes immense sense. Even much less fuel efficient petrol cars emit less particulates than the most fuel efficient diesel.

However, from a public policy perspective, the government has made an effective promise to car buyers who buy cars that meet emission norms on the day they are purchased that they can keep them for their lifetime (15 years based on the OTT) as long as they are maintained in line with standards that apply to that car. So banning diesel or petrol cars before 15 years amounts to a breach of that promise - and the government should be liable to compensate buyers for the same. When the Right to Property was a fundamental right, this could have been enforced. Unfortunately, it is no longer the case - and property can be seized by following any due process specified in the law - including court orders. So does the Bombay High Court or the government have the right to ban brand new diesel cars overnight despite the loss and breach of promise this implies? In my understand, Yes. Should they do that? No - what would be morally right is to have a buy back program for diesel cars and a restriction on entry of any non BS6 diesel vehicle in cities.

Should petrol vehicles be banned? Since they are less harmful, probably not. Should EVs be encouraged in cities even if fuelled by coal based power? Yes - since they reduce emissions and smog in cities which is where most people live.

Diesel cars contribute 0.10% of the pie (this is all the BS''s put together) you want the government to go after that? Rest 90% is what they will have to work on in their departments like roads, construction etc, that they will do nothing about and that is okay?

Sounds like what you know? I had gangrene in my leg, so i got my toe nail of that leg trimmed. Now I am good to go.

They will bring bs7, bs8 in a year or two. So I should sell my diesel 6 Crysta off because technology has progressed after I paid around 50% as tax value of the on road price from the already taxed salary?

[Noctis]

Originally Posted by humyum

Diesel cars contribute 0.10% of the pie (this is all the BS''s put together) you want the government to go after that?

This is unfortunately not true when it comes to urban concentration of pollutants in general and NOx in particular. As Hayek rightly points out the issue of global warming (overall CO2 levels) is entirely different from the issue of poor air quality within population centres. It's the latter where older diesel vehicles play a role.

To back it up with some stats, data from 2022 shows 69% of NOx in the UK came from the transport sector, with passenger cars constituting 37% of that. Given diesel engines release upto 10 times more compared to gasoline, there is no way it forms only 0.1% of the total. The data also shows significant reduction in overall NOx consistent with regulatory restrictions such as from Euro 3 to 6 bringing its limit down from 0.5 mg/km to 0.08. ( SOURCE )

As car enthusiasts this is a rather emotive subject for us and I agree the government must not unilaterally push bans on products that we have already been taxed 15 years for. But it's a fact that older diesels (BS3/4) are a key contributor to urban pollution.

[sunilarkt]

Originally Posted by invidious

The Bombay High Court has asked the Govt
Source: Rediff

I wish Judicial would stick to their domain and avoid unnecessary and impractical activism on their part. Decisions like the "diesel ban" on big metropolises have a huge impact on middle and lower middle-class families. It is not just a black-and-white decision, and we are still a growing economy.

[Fuldagap]

With this all hullabaloo going on about Bombay High Court, 10 year old, 15 year old vehicle ban, otto cycle, Diesel cycle, NOX, CO2 etc, many years back there was Jairam Ramesh who was cruelly after anything that was labelled an SUV. He hated them and labelled them as the most evil vehicles for the environment.

SUV sales have rocketted since then and now we have all sorts of govt rules and court orders interfering with the ordinary Indian trying to get a car for his family and livelihood.

This is when babus travel lavishly in swanky cars without a worry. Even more lavishness for people above the babus, the netas. I bet all their cars are now compliant to the latest norms, discarded as per 10 year rule and they dont have to linger on in an ageing Ambassador. Ordinary man looks for an Alto to save on fuel money. Govt wants the best protected vehicle with armours and what not giving out not-interested-in-kilometers-per-litre. Moreover, they fly in planes. Very environment friendly planes. Their drag coefficient is top notch beating any Altos out there.

Quod licet Iovi, non licet bovi

Grew up with vehicles long before even Euro I was there, started driving before Ero I. Had a neighbours Fiat 1100 Padmini 'deluxe' in its last attempt to fight back the 800. The exhaust gave out a lot of water vapour in the morning. Liquid water after morning. For the time, its engine was great, exhaust was not that much polluting (not visible). BS has come a long way since then, curbed the pollution really a great deal.

Many countries allow any sort of vehicle to ply on road till the rules are followed for re-regsiteration, pollution check and other stuff. One can find beautifully kept old cars plying on road. Do they pollute? Well of course. But the guy bought it with his own money and trying to keep his beloved car in great shape as much as possible.

If data is really crunched, manufacturing a new vehicle is also a major contributing factor to its total life cycle generation of pollution. 30%?
A used car has already paid its dues. With proper upkeep, timely services, good upgrades and modifications, one can argue that old cars also dont produce much. By old cars I mean a car produced during Euro I era. Prior to 1999.

Skies were clear, water was clear in the last 3 decades only during the covid shut down. Factories were shut, no vehicles were plying. No illegal machineries were operating. Major reason being the labourers were forced to leave cities and head back home on foot or by any fataly possible means of travel. It is the men who pollute. Vehicles are just a way to shy away from responsibility. Are Delhi skies clearer now? It has been many years with the 10 year ban.

[Oxy]

Originally Posted by Noctis

But it's a fact that older diesels (BS3/4) are a key contributor to urban pollution.

Sorry for the noob question. I wanted to know if I purchase a new diesel car now, say for example the upcoming Kia Syros, how long does it take for it to become an older diesel?

And if buying a diesel with our hard earned money is such a big risk, why are car manufacturers even allowed to sell them?

[Noctis]

Originally Posted by Oxy

how long does it take for it to become an older diesel?

A good system to determine it will base it on actual emissions of the car while also considering whether any of those pollutants are at a critical level in the city where a restriction is proposed.

A bad implementation will be a blanket year based ban like the one we saw in Delhi.

[alpha1]

Originally Posted by alpha1

I think the more interesting graph is the following one, that should settle the efficacy of banning ancient cars/2 wheelers, and expected improvement (hardly any):

I am observing quite a vivid discussion right from starting of this thread centering abound pollutants, going back and forth.

Of course, every activity that we humans do which is not as per naturally established cycles IS polluting. You think electric vehicles are non polluting? You really believe that there will be zero pollution involved in green hydrogen (wait how do we manufacture PV solar cells and electrolyzers and cabling /wiring again?)

The topic of this thread, and the demonstrable concern all across Indian cities has always been with respect to the VISIBLE pollution caused by suspended Particulate matter. When monsoons get over there is no rains to settle the dust. The large movement of wind stops and there is general air stagnation.

When winters start the wind start blowing from land towards sea, thus collecting and building a caravan of pollutants increasingly as we move downwind. As the subcontinent land mass heats up (Feb onwards), we see clearer skies and lesser pollutants (because winds from yet unpolluted sea blows in)

Every time there is a hue and cry about pollution in NCR, and MMR it is always the haze that sets off the alarm. Haze caused by ... particulate matter. Not CO2, not SOx, not NOx. This is not to say that we shouldn't be concerned about chemical pollutants, but the reality is that public is really not concerned.
So, what causes that particulate matter pollution? Please read the report.

High court, or Green tribunal or XYZ committee, they usually choose to address only the CO2, CO, SOx, NOx part. If so then we will continue seeing public outrage every onset of winters because allowing 5-year-old car instead of 15-year-old car will not reduce PM pollution in any way.

[rakesh_r]

Originally Posted by Oxy

And if buying a diesel with our hard earned money is such a big risk, why are car manufacturers even allowed to sell them?

As long as there is a demand, there will always be a supply. Fate of the Diesel cars will be known once BS7 norms kick in, pretty sure maintaining them will be a royal pain considering the issues faced by BS6.2 Diesel car owners (DPF choking issues).
Looks like the diesel car that i have now will be the last Diesel car i will own.

[Raulspace999]

Yes, the Title is astonishing and is depressing at the same time. Are we looking at a future where banning petrol and diesel vehicles is the only solution? It may be too overarching for sure. Where is the tech to enable alternative fuels and to top it all where is the infrastructure for e-vehicles? Should the average Joe pause his next purchase. Too many unanswered questions.

https://www.moneycontrol.com/news/bu...-12921424.html

[jomson13]

Wow, this one is un-expected!
First there was the news about not being allowed to buy a new car without a proper parking - which does have some merit, but this one is quite retrograde.

I don't see this happening anytime soon in the future - the most they may do is dabble around with the odd - even rule like they did in Delhi.

It would be interesting to note how the OEM's react to this.

[Anwesh]

The following link reports what the state government has submitted to the court.

https://www.hindustantimes.com/citie...246242019.html

I am not sure that what the government says is the real reason for taking such a stand. But hopefully it shall prevail in the court.

Regards,

[deehunk]

If this is going to happen with an intention to push the sale of EVs, the decision will backfire for the state government.