Environment

Diesel vehicles are releasing 50 percent more toxic gas than we realized

It seems clear that current emissions testing for diesel vehicles isn't up to scratch
It seems clear that current emissions testing for diesel vehicles isn't up to scratch
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It seems clear that current emissions testing for diesel vehicles isn't up to scratch
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It seems clear that current emissions testing for diesel vehicles isn't up to scratch

The undisclosed emissions spewing from Volkswagen vehicles may be closer to the rule than the exception, with a comprehensive new study published this week finding that real-world emissions from diesel vehicles have been underestimated by as much as 50 percent. The pollutant in question, nitrogen oxide, is linked to thousands of premature deaths, with the scientists calling for stricter regulations to limit further damage.

In 2014, scientists from the International Council for Clean Transportation (ICCT) and West Virginia University carried out a real-world emissions tests and discovered elevated levels of nitrogen oxide (NOx) coming from Volkswagen's diesel vehicles. This would lead to the company famously admitting it had used "defeat devices," sophisticated software that detects when the vehicle is undergoing official emissions testing and turns on full emissions controls only during that test. These same real-world emissions tests have now revealed that the problem is much more widespread.

An international team of researchers drew on more than 30 of these in-use vehicle emission studies, examining 11 markets that represented more than 80 percent of new diesel vehicle sales in 2015. These studies, the paper's lead author Susan Anenberg explains, use both portable measurement systems (PEMs) to track tailpipe emissions and roadside monitors to track emissions from traffic as it passes.

"The PEMS method gives you a sense for how individual vehicles perform across a range of driving conditions, while the roadside remote sensing method measures emissions from a large number of vehicles for a snapshot of time and in one driving condition where the monitors are located, for example a highway," she tells New Atlas.

Comparing this data on real-world emissions to the official laboratory tests reveals an alarming disparity. The researchers found that the vehicles emitted 13.2 million tons of NOx on the road, 4.6 million tons more than the 8.6 million expected from the laboratory testing.

"Heavy-duty vehicles, such as commercial trucks and buses, were by far the largest contributor worldwide, accounting for 76 percent of the total excess gas emissions," says Josh Miller, researcher at the International Council on Clean Transportation (ICCT). "Five of the 11 markets that we looked at, Brazil, China, the EU, India, and the US, produced 90 percent of that. For light-duty vehicles, such as passenger cars, trucks, and vans, the European Union produced nearly 70 percent of the excess diesel nitrogen oxide emissions."

Nitrogen oxides are a family of poisonous gases that form when fuel is burned at high temperatures. They are strong oxidizing agents that react with volatile organic compounds in the atmosphere to play a major role in the smog that often shrouds cities like Beijing and Los Angeles. They can lead to respiratory problems, headaches, eye irritation and over the long-term have been linked to stroke, heart disease and lung cancer. The World Health Organization classified diesel engine fumes as a Group 1 carcinogenic in 2012.

The study estimates that the excess NOx was associated with 38,000 premature deaths in 2015. And looking forward, the numbers get really scary. The scientists project that unless something is done to clamp down on NOx emissions, this number could balloon to around 180,000 early deaths in 2040.

"The problem of excess diesel NOx extends beyond defeat devices and results in part from emission certification testing cycles that do not reflect the full range of real-world driving conditions," Anenberg tells us.

So it seems clear that current emissions testing for diesel vehicles isn't up to scratch, so what's the answer? The researchers point to the Euro 6 standard as their guiding light. Introduced in September 2015, this standard targeted diesel vehicles specifically, cutting the maximum allowable NOx emissions from 180 mg/km to 80 mg/km.

The researchers believe that implementing these standards for heavy duty vehicles elsewhere would go a long way to improving the situation. But they would like to see things taken even further, stating that stricter "next generation" regulations could help to avoid most of the projected 180,000 premature deaths in 2040.

The paper was published in the journal Nature.

Source: University of York

9 comments
VincentWolf
So that makes VW twice as big a liar huh?
guzmanchinky
Those quick charging batteries from Tel Aviv cannot arrive soon enough...
DDarwin
This is something ridiculous. Do you have the same study about petrol engine? nop, that means petrol engine can produce more pollution than Diesel Engine. And if you take into account the electric vehicle which is the futur for me but not with Batterie - How do you produce the electricity? Nuclear? Coal? Solar? And the same guys who were saying that Apple and Samsung were anti-ecologist due to the production of battery for the smartphone, want know to have some battery for vehicle (how many smartphone battery for one single car?). That's crazy!
Steve-L
This article is so unfair. It doesn't mention that 90% of the worlds NO emissions result from agriculture's use of nitrogen rich fertilizers nor does it mention gasoline engine vehicles or general industry contributions. In actual fact, NO emissions from diesel engines contribute only a small percentage of the total. Further to my point NO emissions occur when the combustion temperature reaches about 3500F, so industry applies Band-Aids to reduce combustion temperature that reduce overall fuel efficiency, which is contrary to everyone's end goals and or they inject Urea into the exhaust stream. The by product of which is Ammonia, which is a huge corrosive and anything but healthy.
swaan
@DDarwin With fossil fuels there is nothing even to recycle. At least with solar, wind and batteries you can turn them into raw materials again. Li-ions are fairly new but we already know that almost all lead-acid batteries are recycled in the developed world. Very few automotive li-ion packs have reached the end of their usable life and the chemistries are still rapidly changing so it is way too early to say anything about the recyclability of various li-ion battery packs. Some new compositions allow batteries to have an usable life (warranties) far longer than cars generally have so it might take a while until we have large li-ion recycling centres.
christopher
So what? Our race is going to burn every last drop until it's all gone, regardless of what anyone does or says anyhow. Maybe renewals will make worldwide fossil fuel supplies last a year or so longer, but nothing we do will have any noticeable or measurable effect: big oil isn't going to stop drilling, and transporters aren't going to stop consuming. Get over it.
The Bishop of D
Until battery technology improves substantially (i.e., energy density by about an order of magnitude, reduction of charge time by the same factor, and cost reduction until it undercuts conventional and hybrid power trains, there will be a need for chemically fueled vehicles. In that context, diesel engines are superior to gasoline engines for many reasons including, but not limited to superior thermodynamic efficiency. Ultimately, their single best advantage is the ability to burn biofuel, something which effectively closes the carbon cycle feedback loop. The use of biofuels will also make them more efficient and they will perform better (I know because I run B100 in mine).
Catweazle
More alarmist claptrap. Modern diesels are massively less polluting than those made only a decade ago. The whole NOX scare is just another method of raising taxes and taking perfectly serviceable vehicles off the road to sell new ones - a thoroughly ecologically unsound practise. The trouble is, diesels are more efficient than petrols for two reasons, primarily because they run much higher compression ratios which means that the top combustion temperature is considerably higher than with petrol engines and secondarily because on diesels the air inlet is unthrottled, so improving the pumping efficiency. Problem with higher temperatures and pressures is that the higher they are more oxygen combines with nitrogen to form oxides of nitrogen, entirely irrespective of the type of fuel used. Another matter that appears to be currently overlooked is that of deteriorating catalytic converters. Currently there is so much very finely divided platinum and iridium in road dust that it is economically viable to extract them, and it seems to me that if carbon particulates are harmful when inhaled, platinum and iridium particles are likely to be a great deal more so.
ljaques
Yes, more alarmist claptrap, but when they took perfectly good diesel engines and started the latest round of emissions control, they took perfectly -harmless- large carbon flakes out of the air (prettier) and made them smaller and made them deadly to humankind. I just don't get these idiots who say they're trying to help. If you want to help prevent premature deaths, roll back the emission control devices on diesels and start controlling doctors and nurses. With a million deaths per year due to negligence, that's at least 5x the deaths of your NOX emitters. And maybe require emission controls on off-road machines, too. They're getting a free ride on our nickel.