One idea frequently cited as a way of reducing pollution is the use of scrappage schemes and low-emission zones to persuade people to replace their old cars with newer, 'more efficient' ones. IMHO this is a very bad idea, for several reasons:

  1. As per this question and this question, it is generally more sustainable to keep an old car for longer than to create a new one, with all the associated pollution of the manufacture process.

  2. We've just had the 'Dieselgate' scandal following the last attempt, where the supposedly more efficient Diesels were found to be cheating the system. How do we know that EVs won't have a similar problem, e.g. when it comes to recycling the batteries?

  3. Such schemes only benefit those who can afford to buy a new car already - those who can't are penalised by either having to get into massive debt to pay for the bulk of the cost, or by losing the natural supply of older second-hand cars they rely on. This is even more of a problem if the scheme is accompanied by low-emission zones or other regulatory sticks.

  4. EVs still produce just as much particulate matter from their tyres and bakes (in fact slightly more, as they are heavier). Getting rid of tailpipe emissions won't help with that.

I believe that it is much better to solve the problem by reducing the amount that people need to use their cars - for example by:

  • Promoting flexible & remote working so that people don't need to commute as much
  • improving public transport & walking/cycling infrastructure
  • enabling people to live closer to their work (e.g. by encouraging companies to open offices in suburbs/provincial towns instead of always in the city centre)
  • eliminating the 'school run' by making it easier/safer for people to walk their children to school. This also helps reduce childhood obesity.

The question is - am I right with this belief, and how can I persuade people to look at these concepts instead of the 'knee-jerk' banning/restriction approach

  • Suggest you edit your question to ask for alternate arguments favouring re/continued use. Feb 25, 2019 at 19:57
  • 1
    Your third point can be generalized to changing our zoning system so that business can be mingled with residential so more people can walk to work. Feb 25, 2019 at 19:59
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    Regarding point 4 - electric vehicles don't necessarily generate more particulates from their brakes, as the regenerative braking systems can provide considerable retardation by themselves - it will depend on the model but cars such as the BMW i3 or Nissan leaf can supposedly be driven around with very little use of the brakes. I agree with the main thrust of your argument though.
    – John M
    Feb 26, 2019 at 14:30

2 Answers 2


I actually think such scrapping schemes are a very good idea, for these reasons:

  1. Car manufacture takes probably around 10%-20% of the emissions it would create during its lifetime. Where I live, useful car lifetime is considered to be 300 000 km. If you have the ability to charge an EV at a time when no carbon-emitting thermal power plant is generating electricity, the emissions created by marginal increase of energy use are very low indeed.
    • Source: this link says 23% of emissions of standard gasoline vehicles are in production. Note it assumes car is scrapped at only 150 000 km. When scrapping at 300 000 km, it would be more like 13%.
  2. You don't recycle EV batteries. You reuse them for grid energy storage. When EV batteries have only 50% of their capacity left, they are still very useful for grid energy storage. Also, you could consider EV batteries as a very high grade ore. Extracting materials from such a rich ore is much less harmful to the environment than extracting materials from some random ore low in richness in a random mine.
    • Source: this link illustrates such an idea has already been implemented!
  3. The schemes I have seen are based on giving some economical benefit to the potential buyers of new cars, and funding it by collecting taxes from those with an ability to pay taxes, rather than mercilessly placing a very high cost on the owners of old vehicles. Also, if you support the purchase of new cars, the benefits trickle down to the buyers of used cars as well by reducing the resale value of them.
  4. The particulate matter from diesel tailpipe is much much smaller in diameter when compared to particulate matter from tires. Therefore, diesel particulate matter is more harmful for the health of people who have to inhale excessive amounts of it. Also, if you really want to (at the expense of traffic safety) reduce harmful particulates in the air we breathe, you could ban studded tires. Many cities have done so.
    • Source: this article says tires generate about 0.1% - 1% of tailpipe emissions.

So, I would say your premise is flawed. Currently, we are at an intermediate stage where EVs are still not cost-competitive when you consider only the cost to you, but they are cost-competitive when you consider negative externalities of gasoline or diesel powered cars.

Of course, such scrapping schemes should have some means of preventing misuse. E.g.:

  • You have to scrap a car that is at least N years old with emissions at least M g / km
  • You have to buy a new car with emissions at most L g / km
  • 1. The figures I've seen are nearer 50% (theguardian.com/environment/green-living-blog/2010/sep/23/…). 2. Good point. 3. The schemes they have had here require the scrapping of the old car (hence the name), thus reducing the supply of used cars and therefore increasing the cost. 4. I understood both to be PM2.5? We don't have studded tyres here in the UK anyway, and the tyre pollution is reckoned to be nearly 50% of the emissions from an average car, trending up towards 80% for EVs
    – Nick C
    Feb 26, 2019 at 9:53
  • Re your edit on point 4 - I'll refer you to the Defra study I linked in this answer: sustainability.stackexchange.com/a/6877/4155 - which found the non-exhaust emissions to be 38% of the total vehicle emissions in 2009, with a prediction of 59% for 2015 and 81% for 2020.
    – Nick C
    Feb 27, 2019 at 10:59

Several major cities around the world have banned vehicles with internal-combustion engines but the ban is many years into the future.

A more reasonable vehicle ban would be to limit internal-combustion engine size in business districts and during business hours. A limitation on engine size could begin immediately because there is commuter rail, commuter bus, city trains, and city buses for those with problem vehicles.

Something else that can be done would be to require, for instance, a minimum of three vehicle occupants instead of two for vehicles in HOV lanes. Or even have the HOV lanes for commuter buses only.

But banning vehicles based on age is a superficial logic. The aged vehicle might be correctly maintained or even have a rebuilt engine. And vehicle emission tests require that vehicles be maintained.

  • This doesn't make sense. Based on your suggestion, everybody should drive a 50cc two-stroke moped with no catalytic converter, and an energy-efficient low-emission 2.5 litre naturally aspirated Atkinson cycle hybrid-electric engine like I have will be forbidden.
    – juhist
    Feb 27, 2019 at 22:47
  • I didn't say to give up vehicle emission standards I just said to additionally limit engine size. In fact the MPG requirements that are in addition to emission requirements, the MPG standards tend to encourage smaller engines. And the suggested engine size limit was for high air pollution areas of major cities. To really reach for a result, lightweight vehicles with small engines are only available in high performance cars, they are not available in sedans. The idea would be something like a Camry, which is a midsize four-door car, at 2500 pounds weight and an engine size of 1.8 ,
    – S Spring
    Feb 28, 2019 at 1:49
  • Well, engine size, when not electric motor or when not hybrid, could be limited in size but then midsize cars would have lower performance. Midsize cars would have lower performance if not built with lightweight construction methods. Examples of lightweight vehicle construction methods are Alfa Romeo 4C, BMW i3, BMW i8, Chevrolet Corvette, Lotus Elise, and Lotus Evora. Now these types of vehicle construction methods have not yet been applied to midsize sedans. But a city limiting the engine size that could operate in high pollution areas that favors small cars or mid-size cars w/ 2.4 .
    – S Spring
    Feb 28, 2019 at 2:28

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