3 ms·

Conservation of mass. Fuel turns into CO2, H2O, nitrous oxides and a couple of worse things. Out of that, only H2O isn't a pollutant. Every liter (or every gram

Conservation of mass. Fuel turns into CO2, H2O, nitrous oxides and a couple of worse things. Out of that, only H2O isn't a pollutant. Every liter (or every gram) of fuel must fly out of the exhaust as one of these things, otherwise it would accumulate inside the car. Now compare how many liters (grams) of fuel you use per year, versus how many grams of break pads and tires. That figure simply cannot be true, it sounds like a convenient myth circulated by oil industry.

mindslight 6y ago
Referencing conservation of mass doesn't make sense. While CO2 is technically a "pollutant", it's not in the same league as the others. Particulates affect air quality in a way that CO2 does not.
generj 6y ago
The claim isn’t that brakes and tires contribute the most pollutants, but the most particulate pollutants. Specifically, PM10, hard particles below 10 micrometers. CO2, Nox, etc from a car are hot gasses which expand relatively quickly, so dumping kilograms and kilograms of them is required to raise ambient air measurements above unsafe zones (measured in ppbs usually, see [0] for the EPA standards for NOx, PM, lead, etc). Particulate matter, being solid, doesn’t spread as quickly as gasses. Small enough particulate emissions can be ingested into the lungs, and from there into the bloodstream. Once there, they can scrape blood vessels, eventually leading to plague and various heart conditions. Very trace amounts of PM10, and specifically smaller PM2.5 that can slip through the lungs easier, can have terrible health outcomes. In the EPA standards I linked, ug/m^3 is roughly equal to ppb, so the standard for PM2.5 is about 1/5 the level of NO2. ICE engines generally only develop PM10 particles from insufficiently high temp combustion. For modern cars it isn’t absurd to suspect that brakes and tires produce more PM10. Here’s a summary of research done on the matter [1]. If you live in Europe, the US, or Canada, indoor and outdoor PM2.5 emissions will shave a few months off lifespans. China’s lifespans may be cut by as much as 5 years from particulate matter. [2] (not a scholarly source but links to them) [0] https://www.epa.gov/criteria-air-pollutants/naaqs-table https://www.epa.gov/criteria-air-pollutants/naaqs-table [1] https://publications.jrc.ec.europa.eu/repository/bitstream/JRC89231/jrc89231-online%20final%20version%202.pdf https://publications.jrc.ec.europa.eu/repository/bitstream/J... [2) https://qz.com/1071421/this-is-how-much-of-your-life-air-pollution-is-stealing-from-you-based-on-where-you-live/ https://qz.com/1071421/this-is-how-much-of-your-life-air-pol...
- trickstra 6y ago
  > The claim isn’t that brakes and tires contribute the most pollutants, but the most particulate pollutants. Yes, but that's the "spin", the gaslighting. "Hey, don't look at the huge amount of other pollution our gas vehicles produce, instead look at this small portion where we are not the main villain. Repeat after me: Baaaad break pads, baaad!!" Fossil fuel industry is fighting for their survival. Even if I agree with the numbers and the research, I can't agree that we should focus on this. The greenhouse gases pollution is a much bigger problem, EVs solve that, so if their break pads still produce the same amount of particulates, what does it matter? Don't let them get away with "see those EVs are not as good as you were told".
  - generj 6y ago
    Focusing on PM pollution tends to reduce CO2 emissions. Most PM 2.5 comes from burning fossil fuels, so insisting on lower levels means burning fewer fossil fuels. PM studies are able to tie pollution directly to lives and thus dollars (through statistical lives). So, if reducing coal use costs $2.7B a year, but we extend enough lives, prevent asthma, etc., to equal at least $2.7B then as a country we should enact the regulation. The US starting doing exactly this from 1996-2003 and it reduced CO2 emissions by making coal plants, steel mills, etc., more expensive to operate. As a result, PM studies like the Harvard Six Cities study were highly controversial and fossil fuel companies lobbied hard against them. It is a lot harder to tie climate change to direct costs because the impacts are somewhat fuzzy and on a long timeframe. In this case, discovering brake pads and tires cause PM2.5 means we can invest in less-emitting brake pads. But this isn’t likely to produce tires/brakes that dramatically reduce emissions. A more likely approach is investing in mass transit, which would reduce CO2 output. I wouldn’t say greenhouse gasses are a larger problem but a rather a harder to coordinate long-term global problem. PM pollution caused 4.2 million premature deaths in 2016 [0]. It is hard to directly state how many deaths climate change caused in 2016 but conservative estimates [1] are for about 500,000 deaths a year by 2050. Most PM deaths stem from terrible industrial air in poorer countries which if combated would also dramatically cut CO2. [0] https://www.who.int/news-room/fact-sheets/detail/ambient-(outdoor)-air-quality-and-health https://www.who.int/news-room/fact-sheets/detail/ambient-(ou... [1] https://www.cnn.com/2019/01/16/health/climate-change-health-emergency-study/index.html https://www.cnn.com/2019/01/16/health/climate-change-health-...

mindslight 6y ago

Referencing conservation of mass doesn't make sense. While CO2 is technically a "pollutant", it's not in the same league as the others. Particulates affect air quality in a way that CO2 does not.

generj 6y ago

The claim isn’t that brakes and tires contribute the most pollutants, but the most particulate pollutants. Specifically, PM10, hard particles below 10 micrometers. CO2, Nox, etc from a car are hot gasses which expand relatively quickly, so dumping kilograms and kilograms of them is required to raise ambient air measurements above unsafe zones (measured in ppbs usually, see [0] for the EPA standards for NOx, PM, lead, etc). Particulate matter, being solid, doesn’t spread as quickly as gasses. Small enough particulate emissions can be ingested into the lungs, and from there into the bloodstream. Once there, they can scrape blood vessels, eventually leading to plague and various heart conditions. Very trace amounts of PM10, and specifically smaller PM2.5 that can slip through the lungs easier, can have terrible health outcomes. In the EPA standards I linked, ug/m^3 is roughly equal to ppb, so the standard for PM2.5 is about 1/5 the level of NO2. ICE engines generally only develop PM10 particles from insufficiently high temp combustion. For modern cars it isn’t absurd to suspect that brakes and tires produce more PM10. Here’s a summary of research done on the matter [1]. If you live in Europe, the US, or Canada, indoor and outdoor PM2.5 emissions will shave a few months off lifespans. China’s lifespans may be cut by as much as 5 years from particulate matter. [2] (not a scholarly source but links to them) [0] https://www.epa.gov/criteria-air-pollutants/naaqs-table https://www.epa.gov/criteria-air-pollutants/naaqs-table [1] https://publications.jrc.ec.europa.eu/repository/bitstream/JRC89231/jrc89231-online%20final%20version%202.pdf https://publications.jrc.ec.europa.eu/repository/bitstream/J... [2) https://qz.com/1071421/this-is-how-much-of-your-life-air-pollution-is-stealing-from-you-based-on-where-you-live/ https://qz.com/1071421/this-is-how-much-of-your-life-air-pol...

trickstra 6y ago
> The claim isn’t that brakes and tires contribute the most pollutants, but the most particulate pollutants. Yes, but that's the "spin", the gaslighting. "Hey, don't look at the huge amount of other pollution our gas vehicles produce, instead look at this small portion where we are not the main villain. Repeat after me: Baaaad break pads, baaad!!" Fossil fuel industry is fighting for their survival. Even if I agree with the numbers and the research, I can't agree that we should focus on this. The greenhouse gases pollution is a much bigger problem, EVs solve that, so if their break pads still produce the same amount of particulates, what does it matter? Don't let them get away with "see those EVs are not as good as you were told".
- generj 6y ago
  Focusing on PM pollution tends to reduce CO2 emissions. Most PM 2.5 comes from burning fossil fuels, so insisting on lower levels means burning fewer fossil fuels. PM studies are able to tie pollution directly to lives and thus dollars (through statistical lives). So, if reducing coal use costs $2.7B a year, but we extend enough lives, prevent asthma, etc., to equal at least $2.7B then as a country we should enact the regulation. The US starting doing exactly this from 1996-2003 and it reduced CO2 emissions by making coal plants, steel mills, etc., more expensive to operate. As a result, PM studies like the Harvard Six Cities study were highly controversial and fossil fuel companies lobbied hard against them. It is a lot harder to tie climate change to direct costs because the impacts are somewhat fuzzy and on a long timeframe. In this case, discovering brake pads and tires cause PM2.5 means we can invest in less-emitting brake pads. But this isn’t likely to produce tires/brakes that dramatically reduce emissions. A more likely approach is investing in mass transit, which would reduce CO2 output. I wouldn’t say greenhouse gasses are a larger problem but a rather a harder to coordinate long-term global problem. PM pollution caused 4.2 million premature deaths in 2016 [0]. It is hard to directly state how many deaths climate change caused in 2016 but conservative estimates [1] are for about 500,000 deaths a year by 2050. Most PM deaths stem from terrible industrial air in poorer countries which if combated would also dramatically cut CO2. [0] https://www.who.int/news-room/fact-sheets/detail/ambient-(outdoor)-air-quality-and-health https://www.who.int/news-room/fact-sheets/detail/ambient-(ou... [1] https://www.cnn.com/2019/01/16/health/climate-change-health-emergency-study/index.html https://www.cnn.com/2019/01/16/health/climate-change-health-...