This Is Your Air Without CARB

[ssamalin]

https://www.nytimes.com/2017/02/17/w...T.nav=top-news

This is why CARB compliance is the crowning achievement of diesel technology.

[bluesmoker]

Originally Posted by ssamalin

https://www.nytimes.com/2017/02/17/w...T.nav=top-news

This is why CARB compliance is the crowning achievement of diesel technology.

well i disagree, the issue is not European emission standards per se, but the complete lack of enforcement of standards and rampant tampering and bypassing of emission control devices. Cat deletes, dpf deletes etc are being completed without any fear of failing the MOT test because the emission standard (below) is simply visual smoke test and a rudementary visual test.

To get around the visual test, vendors are now selling fake dpfs and cat converters.

https://www.facebook.com/darksidedev...62408097110091

https://www.gov.uk/government/upload...th-edition.pdf

I wonder what the smog would be like if the MOT actually failed cars with tampered emission controls.

[Mark_J]

You really think the tiny numbers of vehicles that the owners install delete kits make a dent in extra smog. I doubt it. I am not defending deleting the exhaust, just being practical. If we want to make a difference in the air quality, countries like China that dump every thing into the rivers, and smog so bad you can't see 1/4 mile, and all that smog eventually ends up in the US and the world. The US and Canada have done a lot to clean up the environment, and if the rest of the world were as clean as our environment, things over all would be cleaner. Also we have western developed cities like the British Columbia capital of Victoria which has for years have dumped tens of millions of gallons of raw sewage every day into the waters separating Washington state and Vancouver Island. The city has been ordered to clean up it's act, but all they currently do is sewage is currently screened for solid objects larger than about a quarter-inch, but it isn't treated beyond that. The wastewater is pumped out of two outfalls that run about 213 feet deep and about a mile into the strait. And they wonder why we have to close crabbing in the sound as often as we do. It's because of raw sewage being pumped into the sound for years. So I think our own countries, including the USA and Canada, need to clean up our own back yards before calling out other countries because we look pretty darn hypocritical.

[tadawson]

Originally Posted by ssamalin

https://www.nytimes.com/2017/02/17/w...T.nav=top-news

This is why CARB compliance is the crowning achievement of diesel technology.

No, that's the air when the nuts at CARB are allowed to spew their toxic fictional blather into it

[turbovan+tdi]

Blah blah blah, its always the diesel engines fault.

[tikal]

Originally Posted by ssamalin

https://www.nytimes.com/2017/02/17/w...T.nav=top-news
This is why CARB compliance is the crowning achievement of diesel technology.

Could there be more than one factor contributing to 'bad air quality' in urban areas?

Looking at this link I see Los Angeles Metro and San Jose Metro in the top 'bad' spots:

http://www.lung.org/our-initiatives/...d-cities.html?

[aja8888]

Someday, the air on earth will be pristine, but that's only when all the humans are extinct.

[GoFaster]

European emission regulations in general lagged behind those in North America and the climate in much of Europe is such that older vehicles stay on the road a long time (and yes, Los Angeles is like that, too). No question the manner in which the emission regulations were enforced in Europe (if it passes the test, it's all good, and what happens outside of the test procedure doesn't matter) which led to cheating, did not help matters.

But let's not forget that it wasn't CARB that flagged and identified VW's cheat. That took a bunch of students doing a science experiment!

[Lug_Nut]

Originally Posted by GoFaster

....(if it passes the test, it's all good, and what happens outside of the test procedure doesn't matter) which led to cheating, did not help matters."

Now if we would drive, all the time, as we did when taking our license exam.......

[wxman]

The major objection I have to CARB regulation policy is that they developed emission standards that essentially ignored valid research results. It was known for decades (since the 1970s) that ozone levels increased on weekends in Southern California relatively more than weekdays even though precursor emissions were significantly lower on weekends than weekday, especially NOx.

This 2003 article offers a good summary of the "weekend ozone effect" research.

In spite of that, CARB proceeded with LEV 2, which mandated a 8.6-fold reduction in NOx emissions (from 0.6 g/mi in Tier 1 to 0.07 g/mi in LEV 2), while only mandating a 3.4-fold reduction in NMHC (from 0.31 g/mi in Tier 1 to 0.09 g/mi in LEV 2).

Even though air quality has generally improved there, ambient ozone remains a significant issue:





Meanwhile, no area in the U.S. is currently in non-attainment with the NO2 NAAQS. CARB's approach is really backward from what it should have been with respect to mobile emission regulations.

[flee]

Originally Posted by wxman

The major objection I have to CARB regulation policy is that they developed emission standards that essentially ignored valid research results. It was known for decades (since the 1970s) that ozone levels increased on weekends in Southern California relatively more than weekdays even though precursor emissions were significantly lower on weekends than weekday, especially NOx.
edit
In spite of that, CARB proceeded with LEV 2, which mandated a 8.6-fold reduction in NOx emissions (from 0.6 g/mi in Tier 1 to 0.07 g/mi in LEV 2), while only mandating a 3.4-fold reduction in NMHC (from 0.31 g/mi in Tier 1 to 0.09 g/mi in LEV 2).
Even though air quality has generally improved there, ambient ozone remains a significant issue:
edit
Meanwhile, no area in the U.S. is currently in non-attainment with the NO2 NAAQS. CARB's approach is really backward from what it should have been with respect to mobile emission regulations.

Please note that this improvement is despite a 3-fold increase in vehicle miles driven over the last 40 or so years.

[wxman]

Originally Posted by flee

Please note that this improvement is despite a 3-fold increase in vehicle miles driven over the last 40 or so years.

I'm not suggesting that regulations aren't necessary. However, the ONLY reason for emission standards is to facilitate attainment with ambient air quality standards (NAAQS in the U.S.)

CARB has taken the NOx-control approach to reach attainment with the ozone NAAQS (which was reduced to 70 ppb in December 2015 from 75 ppb), despite research suggesting this is not the best approach. The success of this approach is dubious to date. For example, according to EPA monitoring data, ambient concentration of NO2 in Los Angles has been reduced by nearly 45% between 2000 and 2014 (from 123 ppb in 2000 to 69.4 ppb in 2014), but ambient O3 levels have only decreased by about 15% (from 85 ppb in 2000 to 72 ppb in 2014). NO2 levels in San Bernardino decreased by about 42% but O3 decreased by 12%.

According to a recent study (Fujita et al., "Projected ozone trends and changes in the ozone-precursor relationship in the South Coast Air Basin in response to varying reductions of precursor emissions." J Air Waste Manag Assoc. 2016 Feb;66(2):201-14. doi: 10.1080/10962247.2015.1106991), another 90% reductions in NOx from 2008 levels will be required to reach attainment with the O3 NAAQS. In 2008, ambient NO2 was 79 ppb in San Bernardino. A 90% reduction from 79 ppb would mean that NO2 levels would have to be no more than about 7.9 ppb in order to attain O3 NAAQS.

This may be a difficult target to hit even if all anthropogenic NOx emissions are eliminated, because another study (Oikawa, P. Y. et al. “Unusually high soil nitrogen oxide emissions influence air quality in a high-temperature agricultural region.” Nat. Commun. 6:8753 doi: 10.1038/ncomms9753 (2015)) found very high levels of biogenic/geogenic NOx emissions from agricultural soils in SoCAB.

[tikal]

wxman, what about volatile organic compounds (VOCs) and other pollutants from gasoline cars (and gasoline production/delivery) slowing the drop of ozone pollution in the Los Angeles Basin?

https://www.esrl.noaa.gov/csd/news/2012/119_0809.html

"The 98 percent drop in VOCs in the last 50 years does not mean that ozone levels have dropped that steeply; the air chemistry that leads from VOCs to ozone is more complex than that. Ozone pollution in the Los Angeles Basin has decreased since the 1960s, but levels still don't meet ozone standards set by the Environmental Protection Agency."

I agree with you that EPA/CARB put most of their attention on diesel vehicles and delayed putting gas particle filters (GPF) and other measures for gasoline cars until 2018-19 time frame. The result is, in my view, a mediocre return on investment so far in terms of ozone and other ground level pollutants for our cities.

[turbovan+tdi]

Originally Posted by flee

Please note that this improvement is despite a 3-fold increase in vehicle miles driven over the last 40 or so years.

And how many millions more cars on the road?

[wxman]

Originally Posted by tikal

...The result is, in my view, a mediocre return on investment so far in terms of ozone and other ground level pollutants for our cities.

Completely agree.

In its zeal to further reduce NOx emissions, CARB has petitioned the EPA to reduce NOx emissions from diesel trucks, from 0.2 g/bhp-hr to 0.02 g/bhp-hr. EPA has apparently accepted the petition and will be issuing a Notice of Proposed Rulemaking soon. Even though it appears additional NOx control after-treatment may allow diesel truck engines to attain this NOx emission level (https://www.arb.ca.gov/msprog/hdlown...x_research.pdf), it means even more cost and marginally higher fuel consumption.

In the meantime, "near zero" natural gas engines are being promoted as a low-NOx solution (http://www.cert.ucr.edu/research/efr...G_Finalv06.pdf). However, according to that paper:


"…NH3 concentration varied from 118 ppm (UDDS) to 305 ppm (CBD)…" [not detectable – 1.369 ppm in ACES 2, the emission study of 2010-compliant diesel engines]

"…CO emissions ranged between 1.3 to 5.3 g/bhp-hr…" [0.023 g/bhp-hr – 0.096 g/bhp-hr in ACES 2]

"…NMHC emissions ranged from 0.003 g/bhp-hr to 0.594 g/bhp-hr…" [0.000 g/bhp-hr - 0.000 g/bhp-hr in ACES 2]

"…The ISL G NZ and ISL G both show higher PN emissions compared to diesel vehicles equipped with DPFs…." [Page 32]


So the trade-off for lower NOx emissions is higher emissions of all other tested pollutants.