And 16-container ships create as much pollution as all the cars in the world. Perhaps these ships are softer targets to correct than tens of millions of cars?

http://www.dailymail.co.uk/sciencetech/article-1229857/How-1...

Can we have some proper references rather than the Daily Mail. Its the UK's equivalent of Fox news. They have a pro car owning readership, so any headline like this will be welcome to them

The National Resource Defense Council (NRDC): http://www.nrdc.org/international/china-controlling-port-air...

NRDC info graphic: http://www.nrdc.org/international/files/china-controlling-po...

Industry Tap: http://www.industrytap.com/worlds-15-biggest-ships-create-mo...

The Guardian: http://www.theguardian.com/environment/2009/apr/09/shipping-...

Also even their language is phrased such as it says "16 of the world’s largest ships can produce as much lung-clogging sulphur pollution as all the world’s cars"

Note the inclusion of the word 'can' before produce. Making this statistic unreliable without further support.

Additionally, it refers specifically to sulfur compounds, not to air pollution in general.

Ships going from (for example) Europe to Asia switch to the cheaper sulfur bunker when exiting the EU. This could be easily fixed with international regulations so people wouldn't be able to use that misleading argument.

Respectfully sulphur is air pollution and causes significant harm.

From Wikipedia (section of Environmental impact of shipping: Conventional Pollutants)

"...Of total global air emissions, shipping accounts for 18 to 30 percent of the nitrogen oxide and 9 percent of the sulphur oxides.[15] [16] Sulfur in the air creates acid rain which damages crops and buildings. When inhaled the sulfur is known to cause respiratory problems and even increases the risk of a heart attack.[17] According to Irene Blooming, a spokeswoman for the European environmental coalition Seas at Risk, the fuel used in oil tankers and container ships is high in sulfur and cheaper to buy compared to the fuel used for domestic land use. "A ship lets out around 50 times more sulfur than a lorry per metric tonne of cargo carried."[17] Cities in the U.S. like Long Beach, Los Angeles, Houston, Galveston, and Pittsburgh see some of the heaviest shipping traffic in the nation and have left local officials desperately trying to clean up the air.[18]

http://en.wikipedia.org/wiki/Environmental_impact_of_shippin...

Sulfur compounds are one kind of air pollution. No one is saying that sulfur doesn't count, they are saying that other things count too.

Here is the write-up from the Guardian

http://www.theguardian.com/environment/2009/apr/09/shipping-...

> Its the UK's equivalent of Fox news

Not really, it's more like something in between the National Enquirer and the New York Post in terms of journalistic quality. Doesn't really make sense to compare it to TV news.

They produce as much sulfur as all the cars in the world (because cars don't produce very much sulfur). For other types of pollution, cars produce much more.

As far as whacky comparisons go, I'd always wanted to do some back of the envelope calculation comparing smokers' CO2 output to cars'. Also, always wonder how much cigarette filters (that are supposed to capture various chemicals) that get thrown on the floor could contribute to (e.g.) water pollution, if at all.

Why limit it to smokers? The simple, necessary act of breathing emits CO2.

It's a pretty easy calculation considering smoking is basically carbon neutral. Almost all the carbon in a cigarette was removed from the environment by the tobacco plant when it was growing and gets returned to the environment when smoked. At most, cigarettes redistribute carbon from the regions where they grow tobacco to the places where the cigarettes are smoked. If anything, cigarettes deposit a small percentage of its carbon into the lungs of smokers which, after the smoker dies and is buried, is essentially removed from the atmosphere.

However this is only the case for CO2...as you mentioned, cigarettes have a bunch of other nasty chemicals that become pollution when smoked.

These are the last remaining targets.

We started with industrial and home air pollution in the early and mid 20th century, driven by events such as the Great Smog of London. Smokestacks mandated, a great deal of process improvements on industrial sites, and natural gas & electric replaced coal in the home.

We basically solved most automobile car pollution over a period from the 1970's to the 1990's, with class ratings, better engines, catalytic convertors, and mandatory emissions checks, in jurisdictions with lots of people and not a lot of corruption.

That's over. Unless you live in a dysfunctional municipality controlled by the auto industry, or in a rural area where the pollution is so spread out it doesn't make much difference, you have mandatory emissions checks.

For the last ten years, and for the next ten years, we've been dealing with the problem in commercial trucks, a major share of interstate road traffic in the US. Progressively lower sulfur diesels implemented, catalytic converters mandated, and a supplement to the catalytic converters, a diesel particulate filter, mandated.

Regulations vary locally on the matter of small household engines, but the general trend for decades has been to phase out two-strokes in favor of simple four-strokes. A small two-stroke lawnmower will tend to be dirtier on some metrics than thousands of cars combined, and four-stroke engines have weight issues that may disallow handheld machines, so there is some consumer lament, but it's happening anyway. There's probably also some automotive emissions measures that will migrate to the larger ones.

As a result of all this, the road fleet is becoming exceedingly clean. The only things left to clean up are marine (bunker fuel), rail (bunker fuel) and small aviation (leaded avgas) engines, and we're at the beginning of the several-decade process of dealing with those.

Fuel sulfur content is both a primary emissions problem, and a signal. The catalysts required to cut particulate & VOC pollution down to negligible levels are apparently destroyed by sulfur, so it's only once you go to ultra-low-sulfur fuels that you get the option of cleaning up the exhaust. I'm not sure where that leaves sour crude suppliers.

I maintain that, with the rise in ship size, and progress in reactor design, we should re-open the issue of the civilian nuclear fleet. Ships have gotten three times as large in just the last ten years to conserve fuel and serve the globalized economy. Fuel is still 90%+ of their cost structure. The Maersk Triple E class wouldn't even feel weather conditions that would have destroyed the NSS Savanah, and we have developed exceedingly fine bathymetric guidance systems since that era to avoid grounding. We can build proliferation-resistant (piracy-friendly), passively safe reactors without even utilizing the basic nuclear navy 100% failsafe strategy of dumping the reactor in several pieces into deep water to avoid meltdown if cooling systems become overwhelmed. We have had to use that failsafe, best as we can tell, precisely zero times over 5400 reactor-years of the US Navy.

Ships are not usually found in the middle of cities.

As someone who lives next to the port of Oakland, allow me to say that ships are indeed an issue in urban environments, and they do cause large amounts of pollution. And besides the ships, there are usually a number of diesel trucks that are coming to ship goods to and from the port.

Recent state and federal regulations have made this less a problem.

Have you ever been to Long Beach CA? Take a look at the (frequently) dozens of containter and tanker ships idling just offshore. Any major port city will have the same issue, transport ships waiting, for various reasons, just outside of a port with their engines running. Any refrigerated cargo needs to be cools, which requires power, which means that they run 24x7 while sitting around.

there was a push to improve shore-power options for these ships a while back, but i'm not sure where it went. probably deemed to costly or intrusive by the shippers.

It is called AMP, and it happened:

http://www.portoflosangeles.org/environment/alt_maritime_pow...

There has been push back from cargo shippers, but cruise ships are using it. The port of LA has been pretty forward-looking about improving operations efficiency.

The problem is the proximity of humans to cars. The results are form a study done at UofT Eng Dept. The crux of their findings were that it takes much longer than anticipated for the levels of 'pollution', in various form, to drop in concentration with distance from the source. I think the following excerpt from the UofT press release is the most intriguing[1];

“The ultrafine particles are particularly troubling,” says Evans. “Because they are over 1000 times smaller than the width of a human hair, they have a greater ability to penetrate deeper within the lung and travel in the body.”

On a typical summer day in Toronto, Evans’ instruments measure approximately 20,000 ultrafine particles in each cubic centimetre of air. This means that for every average breath, Torontonians are inhaling 10 million of these nano-sized particles. These numbers increases to 30,000 and 15 million in the winter, when there is more stagnant air and less evaporation of the compounds."

[1]http://news.engineering.utoronto.ca/traffic-emissions-may-po...

If I'm not mistaken, those ships are more efficient per unit of cargo than smaller ships. It's one of the main reasons they were built.

Myths again. Sulphur is a relatively local pollutant. Ship sulphur emissions have probably killed a lot of people every year in Europe. Some say thousands. Well, that was until 2015, when the emissions regulations came into force!

Hurray for the European Union! Also Norway is participating.

http://www.imo.org/MediaCentre/PressBriefings/Pages/44-ECA-s...

http://www.airclim.org/acidnews/2011/AN2-11/ship-pollution-c...

sure, lets shut down everything and go tribal

Living in a state (Michigan) without any sort of vehicle inspections, I can usually spot a vehicle that will be especially bad well before I smell it. If I'm driving, I'll punch the recirculate button to head off the issue, and look at making lane changes (or even varying my route) to avoid vehicles. This doesn't work as well if I'm walking or biking, however.

I have asthma, so I'm especially sensitive to this. I'd love to see mandatory smog checks introduced here, but I know that this will never be politically feasible. At least our road salt tends to take old vehicles off the road fairly quickly...

Why would mandatory smog checks never be politically feasible? They are not just a California-only thing.

Because the Big Three car makers and the National Association of Manufacturers run this state. They said it will "increase costs" and "cost tons of jobs" if a smog law was passed, since they will have to spend more to pass the tests.

You would think those groups would be in favor of regular smog testing, as it accelerates the retirement of old vehicles.

The automakers resisted adding smog equipment (which did increase costs), but that battle is already lost. They already make exclusively 49- and 50-state emissions legal vehicles.

It is also a PR thing: they don't want the government to admit that the cars are pollutants.

Because it's Michigan. Smog checks could pass in other states. But probably never in Michigan.

This is the state that wants to revoke healthcare from victims of automobile accidents ( http://www.mlive.com/lansing-news/index.ssf/2015/04/senate_c... ). Automobile manufacturers and related industry still controls most of the state.

It's hard to overstate how small the chance of smog checks happening in Michigan is.

I haven't taken the time to analyze the merits of that bill, but it would not revoke healthcare from victims of automobile accidents, it would restructure how it is provided. In states that do not have a mandatory no fault PIP, people buy a medical policy along with their car insurance:

http://www.dmv.org/insurance/medical-payments-coverage.php

So would many people see a drop in coverage? Probably. Would people be able to obtain medical coverage for injuries resulting from a car accident? Almost certainly.

(My ill informed cynical assumption is that insurers are funding the push to change the system, with the expectation that they will be able to profit more under the proposed changes)

In addition to having a fairly large libertarian-leaning contingent (especially in rural areas), people in Michigan tend to associate personal vehicles with "freedom" at a level probably unmatched anywhere in the country (if not the world).

Michigan is unusually conservative/libertarian. Its a shame children, the elderly, and those with lung conditions pay for this misguided philosophy with their health.

Reality is that it is a Democratic leaning state that hasn't gone Republican in a presidential election since 1988. All the Republican governors in my lifetime have been moderates with the possible exception of Engler who was elected on Reagan's coattails.

http://www.270towin.com/states/Michigan

I find carbureted vehicles the most bothersome (the exhaust stinks of fuel at city speeds), so I guess enforcing emissions standards wouldn't solve the problem (because of grandfathering/exceptions).

There are very few carb'd cars on the road these days in the USA. They were mostly phased out in the 80's and 1990 was the last year of passenger cars that had carbs (and there were only 4 or 5 if I recall)

The problem is you can drive a vehicle that's burning coolant or oil and just spewing a cloud behind it and nothing is really stopping you. I'm not sure if you can actually get a ticket for it or not.

> There are very few carb'd cars on the road these days in the USA.

Yeah, there are less, but on a summer weekend in Southern California you can expect fumes from a number of car-culture enthusiasts and their cars.

My favorite : Carbureted rotaries. The smell of unbalanced air-fuel ratio plus the smell of motor oil being burned in combustion. It's like the two-stroke of the streets. Even better when it has lost a coolant seal and you get that nice sticky white-blue coolant component to the noxious cloud left behind.

Yes, I'm aware.

The thing is, living in Michigan, I notice a lot more older carburated trucks than I do smoking modern vehicles...

They tend to be the worst, but they're not terribly plentiful. The bigger culprits are those oldish (10-20 years old) vehicles that have busted (if not removed) emissions control systems. As long as you enforce the emissions standards in effect the year the vehicle was built, you can get around a lot of the grandfathering issues.

Yes, every time I'm behind or passed by a "classic" older car with carburetors, even one that has been restored and looks like new, I'm surprised by how clearly I can smell the exhaust. By contrast modern cars emit almost no detectable smell. Hard to belive that pre-1980s all cars had exhaust odor like that, I certainly don't remember it from my childhood.

You don't notice it when you are used to it.

Pre '75 there was nothing to control oxides of nitrogen, which smell pretty awful, and combustion was never clean enough back then to control volatiles and hydrocarbons. I think all they had were secondary air injection, which was prone to failure and subsequent removal

You may not remember the smell, but do you remember the color of the L.A. skyline?

I guess the average carbureted vehicle on the road today is being run by someone with the mindset that the engine should run great and develop lots of power. Back in the day more people would have set them up leaner.

The ideal air fuel ratio for gasoline engines is 14.64:1. It hasn't changed. Running an engine too rich wastes fuel and reduces power, too lean causes detonation and can destroy it. Electronic fuel injection more precisely meters the fuel which keeps combustion closer to ideal. Carbureted vehicles are generally tuned as close as possible to ideal but it's always better to go slightly rich than slightly lean.

Couldn't the federal government require it? For example, I know that a number of the most populous counties in Texas require vehicle emissions tests as part of the annual inspection. This being Texas, it's a good bet that they didn't voluntarily decide to do this. With the possible exception of Travis county (Austin).

There are a great many things the federal government could require, but the US is in a constant tug-of-war between federal powers and states rights. Similar to the EU vs its member nations.

Emissions standards for new vehicles is regulated by the EPA.

Having grown up in Michigan (Detroit area), I'd say that Michigan has generally good air quality (excepting acute conditions like asthma) - as long as you live upwind of most other people and factories. That usually means more north and west. And it usually means more expensive real estate. IINM, this air-quality vs. socioeconomic pattern repeats itself across much of the industrial midwest and rust belt.

Maybe that's another reason you won't see smog checks - a lot of voters probably feel their air is fine, and those whose air has high particulate pollution may not vote much - either because the poor just vote less, or because they have bigger immediate problems than local air pollution.

Michigan actually has rather poor-quality air: http://www.stateoftheair.org/2015/states/michigan/

Much of this is due to us being down-wind of Chicago: http://www.epa.gov/med/grosseile_site/indicators/air-polluti...

Sure, it isn't the Canadian Rockies, but it is nothing like a bad day in San Bernadino or Bakersfield. Check out the summer AQI maps for different parts of the country at http://www.airnow.gov/ (site is down right now).

I remember visiting LA from MI when I was a kid in the 80s and "tasting" smog in the air for the first time. Admittedly LA has gotten a bit better since then.

This article would be more helpful with some historical context. At some point in the past, if all cars were equal, 90% of cars produced 90% of the pollution. Over time newer cars replaced most of the old ones, and now it's 25% of cars. But the overall amount of pollution has dropped too. A future clickbait headline will read "5% of cars cause 90% of the pollution!" and sound very alarming, but in fact that's a measure of progress in removing most of the remaining polluters.

If 5% of cars really caused 90% of the pollution in the future, then we should certainly banish those cars, shouldn't we? It would be a very informative title.

Only if those were new cars. If electric cars become the norm, then one day 100% of car pollution will be produced by <<1% of cars, but the total will be so low that it won't be worth worrying about those antique internal combustion cars. Percentages can be misleading.

Here in Europe (well UK and Spain whee I have lived and owned a car) you need to get a check every year for older cars, and that includes an emissions test. Don't you get that in the States / Canada? (It would appear that the study was done in Canada).

Saying that, go to many less developed country and the cars are far worse condition.

My friend always used to claim that the environmental cost of producing a new car took 9 years to counter with the efficiencies in fuel consumption. No idea how true that is, anyone know?

We had a similar program in British Columbia, called AirCare. Unfortunately, people realized that you could use solutions to flush impurities out of your engine, and then if you let your gas tank get close to empty then put a quarter tank of premium in, your car would burn cleaner and get you a pass, even if it would normally fail.

Eventually the program was scrapped, due to fewer cars failing (8%, down from 14%, which is still too high IMHO), and likely as a way of gaining political capital with the public in advance of an election.

Scrapping a program beause it is suceeding (per its own metrics) but not finished yet, is insane.

That's worth remembering with a car as crappy as mine....

Please also consider not poisoning your neighbors.

I live in a big polluted city, and cycle most places. I use the car for the short season at weekends to go kayaking. It has so far passed the emissions test no problem.

In many parts of the States you do, but the strictness of the test varies and the standards are grandfathered.

So, for example, in California (one of the strictest) you must pass a visual inspection, a tailpipe sniffer, and an engine computer scan. There are also many rules about acceptable engine modifications. In other states you may only get an engine computer scan.

As for standards, cars are (rather reasonably) held to the standard they were made to, not the standard of today, and modern cars really are dramatically less polluting than cars from several decades earlier.

Even in California, there are exemptions for: "hybrids, motorcycles, trailers, or gasoline powered vehicles 1975 and older."

...which seems shortsighted. Except for trailers, all of those can have mechanical problems that cause it to pollute far more than they should. My daily driver for a long time was from 1974 and I was never sure why older cars were exempt. If it's a hobby car with historic plates, sure, but if you're driving it every day you should have to follow the same rules as everybody else. In my defense, my old car got 68 mpg and was well fussed-over.

Motorcycles trail cars in emissions improvements & regulations, but they follow nonetheless. Things like electronic fuel injection was not practical on motorcycles until more recent times.

Part of the rationale with the 1975 exemption is that vehicles 1975 and older represent a very small portion of the number of cars on the road, and are driven far fewer miles than average. That beautiful 1966 Corvette didn't last fifty years by being driven every day.

Yes, Ontario (where the study was done), has such a program. An emissions test is required every 2 years on every car more than 7 years old.

The major loophole is that if your car fails, you only have to spend $450 to fix the problem. Spending $450 to improve emissions gives you a pass whether or not it actually fixed the problem or not.

Ontario uses a lot of salt in the winter, so there aren't a lot of old cars on the road.

The salt solution to the pollution problem is somewhat convenient in the end. Cars do rust to pieces far quicker in Ontario than elsewhere.

I'm fairly sure that salt does not differentiate between polluting and non-polluting vehicles.

The number of vehicles on the road that are older than 20 years is shockingly low, especially American brands which rust considerably faster than others. Even cars from 2000 are rare.

In places where there's no extended winter weather I've noticed the cars are often older, with 40+ year old junkers from the 1980s looking, by local standards, no more than ten years old.

The point is it takes time to eat the car away, in which time the car begings to pollute more

Emissions tests in the US are at the state level, not federal. For instance, the state of Virginia has emissions tests. However, the state of South Carolina does not require a test.

In Pennsylvania, emissions tests vary by county. Counties containing or near a major metropolitan area have them. It's likely the same in other states where emissions tests are required somewhere. Allegheny (Pittsburgh) and adjacent counties require it, but Greene (not adjacent, in the southwest corner of PA) does not.

And even in Virginia, it differs at the county level. You don't need to get your car tested in southwest VA.

It does seem odd that the state requires safety inspections but doesn't require emissions tests in every jurisdiction.

Bland County, VA : 18 people/square mile Fairfax County, VA : 2,761 people/square mile Arlington County, VA : 8,309 people/square mile

Any surprise that emissions tests are required in Fairfax and Arlington, but not in Bland County? Largest city in Bland County has a population of 75; it is a different world from the DC suburbs.

And in California, which is often considered the strictest state ever invented by man, we have stringent emissions tests but no safety inspection at all! It really confuses all of the California-bashers when you tell them that.

I don't know, the idea that Californians care more about environmental pollution than human lives seems to fit the stereotypes.

There's a logic to it. A person who values their safety - most do! - has an incentive to deal with safety issues, regardless of whether they are compelled. Less so with emissions issues.

And it can vary within the states. Texas only requires emissions testing in the most populous counties (no point in testing cars in Brewster county with less than 1 person per square mile population density). In the counties with testing, new cars get a 2-year emissions exemption, after which they get tested yearly.

Testing is generally done via the OBD-II port, so the vehicle self-reports it's condition. Vehicles without OBD-II and "other" vehicles use a tailpipe probe to report on exhaust gases.

It varies by region. The other commenters in this thread seem to be from Ontario. In Victoria, where I'm from, your car does not have to meet any kind of standards at all unless it is involved in a collision, in which case an insurance inspector will tell you what needs to be done (if it's an old car they usually tell you to scrap it), or a cop tells you to get it inspected (this is called a Vehicle Inspection ticket). Otherwise, it's sailing rules - anything that isn't expressly forbidden is allowed.

Across the water in Vancouver you do have to pass an emissions test.

In Canada (at least, the part I am in), you can get money if you turn in your old cars, if I remember correctly. They also made it that you must have an inspection done before selling/buying a car, and cars that are not road worthy cannot get sold.

People still find a way to drive, buy and sell pieces of scrap.

In Ontario, Canada the emissions tests are required, but not until the car has seen a lot use: "Generally, you need to get the test every 2 years, once your vehicle is 7 years old. Larger vehicles (called ‘heavy-duty’ vehicles) require the test every year, once they are 7 years old."

http://www.ontario.ca/environment-and-energy/drive-clean-tes...

Not forgeting that for years official government advice (and tax breaks) was "buy diesal cars" which was wrong and is causing considerable death and illhealth and continued problems with air pollution.

http://www.bbc.co.uk/news/science-environment-32512152

In California we do it every other year but with more stringent dynamometer tests.

In North Carolina the worst offenders are actually exempt from emissions test. Vehicles made before 1996 and diesel vehicles don't have to pass any sort of emissions tests.

Italy data point: 4 years after you buy, then every 2 years.

I remember a pollution program in CA where they'd buy 20+ year old cars and junk them. Those cars made most of the pollution then.

This program was a pollution credit program. A factor met its pollution control program by cutting either its own or someone elses pollution by a statutory amount.

Yep, that's still going on. I've received a couple of letters offering to buy my 1993 Toyota MR2. The letters do say something like "If your vehicle is a classic or is otherwise special to you, ignore this letter." It is a bit of a classic -- in any case, it's worth a lot more than the $500 (or $1000? not sure) they're offering.

I believe california will buy cars that can't pass the smog check for $1500 for low income earners and $1000 to others.

http://www.smogtips.com/vehicle_buy_back.cfm

These days "air pollution" means a lot of different things. This article is talking about air quality and particles, such as soot.

This impacts mostly the local air quality and environment, whereas CO2 is a global problem and impacts the climate in ways not necessarily detectable in the local environment.

What i allways ask myself is for example if someone has an old car which polutes more than a new one, what would polute more to buy a new one or to continue to use the old one. Because producing the new car releases a lot of polutants as well. I have never investigated this.

I would rather see a massive uptick in retrofitting newer engines into older cars; I've done it a couple of times on older Volvos (240-940 vintage) and other makes, after the engines got really tired. I'd imagine it's cheaper/easier to just manufacture better engines and ECMs than it is to manufacture new cars, and you get to keep cool old cars on the road.

surprisingly (or not) , this is rather difficult to do in California. There is a referee that has to validate that the engine swap was completed successfully and without compromising the emissions equipment of the swapped engine. Though not every ref judges on the same scale. There have been reports of some requiring that the gas tank from the donor car be swapped as well (very difficult since the tank usually fills a space in original car that is unlikely to match with the recipient).

I'd like to see a more thorough emissions test be implemented (i.e. more than testing at two speeds, enough to gauge all operating conditions) so that it could be more objective in its process. This would also have the benefit of allowing a way to bypass the restrictive modification exception system.

The percentage of emissions associated with the manufacture of a vehicle is at least equal to driving it for its normal lifetime [1].

1: http://www.theguardian.com/environment/green-living-blog/201...

Well you have to assume that if a car is serviceable it will be sold second hand so the pollution isn't really removed. But perhaps that person will be able to scrap an even worse car and the total pollution will go down.

In principle it should be much easier to clean a factory than distributed city air. But in practice it may be a lost cause either way.

That's a sad reflection on out throwaway economy. Obviously repairs are often a much cheaper option. Further cars limited lifespan so 1 new car could mean replacing 15 cars 1 year sooner.

You’re not counting labor costs, tracking down an issue with an older car can be seriously time consuming, and that time costs something like $75-100/hr.

For instance, my fun car had a persistent miss that made it basically undrivable. It took me something like 20-30 hours to find the issues and fix them. I have OBD2 scanners (the real deal, not the toys), all the tools needed, and the ability to read the service manuals and follow the dianostic proceedures.

Someone driving an old pile, isn’t likely to have the time, know how, or funds to fix the old car. So instead of spending $5k to fix the thing, they spend $300/mo on a new (or new to them) car.

Most states limit the max outlay required before they give someone a pass. In some cases, a vehicle requiring repair expenditures over $450 may get a waiver from the state exempting it from further repairs regardless of test outcome.

You can see a lot of details here. http://www.rff.org/Documents/RFF-DP-99-23-REV.pdf Also, repairs often increase fuel economy so not only do city's become far more livable again the net cost is fairly low.

This is why we should move from mandatory emissions checks on all vehicles, to spot checks of the worst vehicles (but we'd need to get the police excited to run a test.)

You'd have to get everyone excited to allow those tests to be run. If you're spot checking the worst vehicles that will more than likely lead to a large proportion of checks occurring in low-income areas.

I don't see why you couldn't do a red-light camera sort-of thing. Spot emissions testers at ground level along with a photo of the offending license plate.

This is my biggest concern with emissions tests- it disproportionately affects lower income people. Not sure how to get around that, other than offering subsidies for them to upgrade/repair to a more efficient vehicle.

But as others have said, there is better low hanging fruit to go after rather than older cars.

What does "badly tuned" mean? I feel like there is a need for a lot more clarity. Anyone have the source study (or know what it is). I'd like to know more.

A summary of the three papers is here: http://media.utoronto.ca/media-releases/traffic-emissions-ma... They just set up some measurement tools by the side of the road and waited for cars to drive by. They didn't check the "tune" of each car or test whether any kind of tune-up would change anything.

Edit: more links!

Naomi Zimmerman's webpage: http://naomizimmerman.com/publications/

Abstract of the relevant paper: http://atmos-meas-tech-discuss.net/8/2881/2015/amtd-8-2881-2...

This PDF is labelled "supplemental" but it looks like the full text of the paper. http://atmos-meas-tech-discuss.net/8/2881/2015/amtd-8-2881-2...

So that's a pretty significant conclusion to draw without any hard data on the "tuned-ness" of a car.

I wonder how much could be attributed to old cars instead. That's something that would be easily measured by identifying the cars. But that may open a different can of worms if they determine people with the oldest cars are the biggest polluters* because it could be seen as an attack on the poor.

* Odds are the old cars are the biggest polluters.. less efficient to start with, more likely to be out of tune, more worn parts, etc. But I don't have any data to state that as a conclusion.

Thanks for your interest in our work! (Lead author on the ultrafine particle mapping paper).

The SOCAAR facility has operated at this roadside location since 2006 and is one of the largest air quality research lab in Canada.

Over the years, we have routinely seen peaks in CO2 as vehicles pass our monitoring station. However, when some vehicles pass, we also see NOx, black carbon or ultrafine particle peak(s).

While we have video footage of the road, it can be extremely difficult to link the measurements to a single passing vehicle. Identifying these vehicles and why their emissions are different from the rest of the vehicle fleet is where the research our heading.

In our old car, the catalytic converter wasn't effective, and the cost of fixing it was more than the car than the car was worth. The check engine light was on constantly as a result, but it was easy to ignore. Judging by the smell of that car's exhaust, it was definitely in the 25%.

Bad air-fuel ratios also cause lots of pollution due to unburned fuel being sent out the tailpipe. I would think that this is less common with fuel-injected vehicles, but there are still plenty of old carburated vehicles on the road, especially where road salt isn't used.

Also, diesel engines have problems with carbon buildup over time, which reduces the combustion efficiency and causes the notorious black clouds of soot. (http://www.bellperformance.com/bell-performs-blog/blog/carbo...).

Badly tuned generally refers to incorrect AFR (air-fuel ratios). These can not only cause lower power, but increase the amount of unburned fuel and other chemicals in the exhaust.

On some high performance cars you can even go as far as using the fuel's injection to cool combustion and decrease knock in the combustion cycle of the engine...sometimes this can lead to a richer AFR (more fuel in exhaust gases) which causes pollution.

Most (if not all) cars decrease the air/fuel ratio on wide open throttle, which ensures lack of air to burn pistons, etc., as well as cooling the charge to allow greater volumetric efficiency. Carburetors had a "power valve" to accomplish this, fuel injected vehicles usually have a vacuum hose attached to the fuel pressure regulator to increase fuel pressure temporarily. A fouled O2 sensor, mass air flow sensor or manifold air pressure sensor could throw off the ratios during normal operation. I'd venture to guess that "badly tuned" implies a misfire (probably a fouled spark plug) causing an entire cylinders worth of raw gas dumped into the atmosphere. This excessive fuel will melt down the catalytic converter which exacerbates the problem.

Indeed. That is why I specifically stated on high performance cars. High performance turbo cars, for example, at WOT generally aim for 11.2-11.8 (pending tuner preference etc etc, but ballpark) AFRs.

GDI cars have the capability of going extremely lean under highway speeds to drastically increase mpg and decrease emissions. This is the beauty of GDI.

These "badly tuned" cars could also have worn out valve seals/piston rings which can cause excess amounts of oil to burn during combustion, adding to the chemicals spewing out the exhaust.

(Worn seals & rings leads to oil burning, not excess fuel consumption)

Indeed. That is what I meant, but alas that is not what my brain wanted to type.

The common term for such vehicles is "gross polluter". Here's a study on them (pdf warning)

http://www.csus.edu/indiv/s/shafizadehk/pubs/UT2004.pdf

It seems there's more to it than just badly tuned - it seems how to drive also effected the results:

"The most surprising thing we found was how broad the range of emissions was," says Evans. "As we looked at the exhaust coming out of individual vehicles, we saw so many variations. How you drive, hard acceleration, age of the vehicle, how the car is maintained – these are things we can influence that can all have an effect on pollution."

Not sure how they can tell "how a car is maintained" or "how you drive" from spot checking 100K with a roadside probe... anyone have thoughts?

They are speculating , but saying it isn't just the car's "genetics" (make model and production year)

"Tuned" is a holdover term from the days of carbureted fuel systems that doesn't have a lot relevance anymore.

Modern cars don't need routine "tune-ups." Yes, if a sensor fails or something like that it can cause an emissions problem, but a properly working engine computer tunes itself, and if it detects anything isn't what it should be, it activates the "check engine" light on the dashboard.

"badly tuned" for minimal emissions, I assume; tuning for maximum power is somewhat different than for minimum emissions.

Here's an article from almost 20 years ago, about the possibility of using roadside pollution detection to identify these bad vehicles: http://www.cnn.com/TECH/9605/27/emissions/

It's not clear to me weather they included big trucks - the ones hauling stuff. They're diesels which make more particulates and in large quantity. If they are not included, then they should be, because it would be stupid to further regulate cars until we know if they're actually making most of the pollution.

I'd like to see a study like this about airplanes, tractor trailers, and container ships.

Add lawn and garden tools.

https://www.google.com/search?q=small+engine+polution

I can't find the article but Google used to think that replacing cars and coal plants(with clean coal) would be enough to curb CO2 emissions but a new study they just released(last 6 months I think) said it wouldn't matter at all. That has changed their strategy from clean coal to carbon sequestration.

It should be "Gallons per mile" not "Miles per Gallon"

I read this article a few years ago, and following article illustrates the point very well.

http://www.mpgillusion.com/p/what-is-mpg-illusion.html

Combining MPG numbers is what the harmonic mean is for :)

Thank you, I've been looking for a name for that function for years.

Duh.

Spend 5 mins on the road in Missouri and you'll see 100 new cars go by with a scant trace of engine noise, and 1 1994 geo metro missing an exhaust, plastic wrap over one window, two doors of different colors, with the driver on a cell phone smoking a pack of Pall Malls, riding on 3 bald tires and a spare, with the rusted tail pipe spewing white smoke. They pull into quick trip and run inside for a bottle of oil so they can fill up the engine before they pump their gas.

Once again, liberal regulations new cars hardly solves any problems, but looks great for pleasing the voters of "blue states." ...sort of like providing tax credits for new home owners for energy efficient homes... Where apartment complexes have air conditioners from 1970 and the tenants pay the electric bills. All these regulations just add cost to doing business without providing any real benefit to the environment. But the regulations buy votes, so why not?

If we want this changed, we really have to start voting for science, which currently, neither party can associate with. Stupid stupid stupid.

In many states it's a largely solved problem, with annual or biannual inspections needed before you can renew your car registration. (along with the ability for police to site you if there's a visible or audible problem)

There are loopholes, though. There are fair number of trucks in my state that are allowed to run dirty diesel trucks with basically no exhaust protections. Their industries (construction? mining?) get some exemptions under the law, I assume. It's utterly stupid, as those trucks probably account for more particulate emissions than all the other vehicles on the road put together. But God forbid someone increase their "cost of doing business" by requiring some improvements.

How long does an old car with bad emissions have to last before it's worse than the environmental impact of replacing it with a new car?

There's also the energy cost and pollution of manufacturing a new car.

That's what I'm asking about.

The fact that 100 new cars go by without a trace is evidence that the regulations work, no?

When I see a car that seems to be putting out a visible and/or smellable amount of smoke/soot/smog, are these the worst polluters? I guess what I'm asking is if visible inspection is a reliable way of detecting these vehicles?

As a programmer my first impression when I read this (if this is actually true) is: "Nice, when we fix those, we'll have done good on car-induced air pollution".

Pareto principle?

https://en.wikipedia.org/wiki/Pareto_principle

Let's legislate the consumer end of things because regulating business which pollute the air by a factor of 1000 is wrong.

Not if you consider carbon dioxide as pollution :P

This math is completely illogical.

Title should be: "25 Percent of Cars Cause 90 Percent of Vehicle Air Pollution"

That's more likely to mislead, because it implies a difference between 'Car' and 'Vehicle', and 'Vehicle' can include trains, ships, planes, etc.

25 percent of Automobiles Cause 90 Percent of [Automobile] Air Pollution.

Even better.

Ok, we've changed to that. Thanks.

Hey this is just like 25% of the people on earth (China) causes 90% of the general air pollution.

And 99% of those 25% are probably in the developing world, and the ex-USSR.

I've been all over the planet, and I have yet to see trucks which emit thick black smoke straight from the engine (no exhaust system) like the ones Russia and other ex soviet states are absolutely chock full of.

Edit: Also, only place on earth I've ever seen a petrol pump with the choices of 60, 80, or 85 octane fuel. Pinkpinkpinkpinkpink.

>Also, only place on earth I've ever seen a petrol pump with the choices of 60, 80, or 85 octane fuel.

If youv'e ever seen a pump with diesel, you've seen a pump with 15-25 octane [1]. Also, I wouldnt confuse octane with energy content -- pure ethanol has an octane rating of 100+, despite having lower energy density than pure gasoline [2].

[1] https://en.wikipedia.org/wiki/Octane_rating

[2] https://en.wikipedia.org/wiki/Energy_density

I'm fully aware that octane isn't energy density - octane is a long chain which prevents pre-ignition - hence pinkpinkpink - pre-ignition - pinking. I had to fill up a mercedes 190E 2.6 on 60 on one occasion, and fuck did it hate it - particularly as I'd lost my exhaust somewhere in the desert. Set off car alarms when I got into town, just by driving by.

My point was rather that they require fuels with such incredibly low octane ratings due to the astonishingly crap compression ratios on ladas, volgas, and yaz trucks, and most soviet technology. The point was that they could run on near-as-damnit bunker oil, watered down with expensive petrol.

Because these vehicles are still in use, they produce an extraordinary amount of pollution, as the low temperature burning that occurs in them results in a crap-tonne of soot.

Same kinda deal with diesels, but again, their diesels will literally run on bunker oil, and you wouldn't believe the incredible clouds of crap that spew forth from them - particularly when they have no exhaust system.

This actually raises a very good question - how come they don't put cetane number on diesel pumps? It would make me feel less nervous about buying diesel from sketchy off-brand fuel stations...

They took measurements in Toronto

The specific quote if madaxe_again missed it:

>Researchers at the University of Toronto looked at 100,000 cars as they drove past air sampling probes on one of Toronto’s major roads.

No, fully aware that this study was in Toronto, but if it's remotely indicative of the variation of the environmental damage car emissions cause, then the problem is vastly exacerbated by old and poorly maintained vehicles driven in less wealthy and/or impoverished parts of the world.

...60 octane? Looking through the Wikipedia page on octane ratings[1] that seems absurdly low.

1. https://en.wikipedia.org/wiki/Octane_rating