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How is building sidewalks a subtractive solution? Every mile of new concrete sidewalk emits about as much CO2 as driving a million miles. In some urban areas,
by jonas21 4y ago
How is building sidewalks a subtractive solution? Every mile of new concrete sidewalk emits about as much CO2 as driving a million miles. In some urban areas, you'll eventually make up for that. In places where people are not going to walk much anyway, probably not.
The most expedient way of "getting people out of their CO2 producing cars" is to focus on the "CO2 producing" part, i.e.
1. Get people into electric cars, which even on the current grid cuts your CO2 emissions by over half due to better efficiency, and
2. Convert the electric grid to 100% clean energy.
And it turns out there's a lot of money to be made in doing this too.
- gjsman-1000 4y agoBut even CO2 producing cars, have you ever heard of a gas-powered leaf blower or chainsaw? Even though efficiency has improved, in 2016 California reported that just 1 hour of a gas-powered leaf blower was the equivalent of taking a Camry from LA to Denver. You aren't going to motivate people to be better for the environment (by, say, buying a more expensive 40MPG vehicle instead of a 35MPG one), when it can so easily be wiped away by a guy just leaving a tool on for a few minutes more. Same situation with banning straws - nobody cares about the 1.6 billion masks in the ocean now (literally).
- jonas21 4y agoCan you cite your source on the leaf blower thing? I'm guessing they're talking about air quality, not CO2 emissions. Obviously, nobody's feeding their leaf blower 40 gallons of gas per hour.
- gjsman-1000 4y agohttps://cleantechnica.com/2021/10/13/its-time-to-ban-gas-powered-landscaping-equipment/ https://cleantechnica.com/2021/10/13/its-time-to-ban-gas-pow... Air Quality, yes; but I will admit CO2 is not compared.
- deleted 4y ago[deleted]
- function_seven 4y agoTo determine CO2, you can just look at the amount of fuel consumed. That'll get you close enough. A leaf-blower running for one hour will burn roughly 1/2 gal. of fuel. A 40mpg car going from LA to Denver will burn about 25 gallons of fuel. That car trip will generate around 50 times as much CO2 as the blower
- sbaiddn 4y agoPretty darn close! It should be well within 90% of the right answer. For a car probably about 99.9%
- calt 4y ago> 1 hour of a gas-powered leaf blower was the equivalent of taking a Camry from LA to Denver Maybe in terms of particulate pollution, but in terms of CO2 that's absolutely unimaginable.
- throwawayf37jg 4y agoNOx might be the bulk of it.
- sbaiddn 4y agoNaw, volatile organics. Compression ratio isn't great on these things since half the time the gas is terrible -> no pressure, no NOx But they are two stroke so a little but of gas and oil leak out on every stroke.
- hannob 4y ago> Even though efficiency has improved, in 2016 California reported that just 1 hour of a gas-powered leaf blower was the equivalent of taking a Camry from LA to Denver. That sounds like nonsense. (FWIW I support banning gas-powered leaf blowers. But your claim is still bogus.)
- sbaiddn 4y agoIt is bogus, because the OP talks about "efficiency" therefore implying CO2 emissions (since energy is the product of making CO2). The OP has confounded the CO2 emissions and volatiles. Where leaf blowers' emission fall apart is volatile organics. Why do you support banning gas powered landscaping equipment? In cities like LA, sure. But how are utilities going to maintain brush around remote power lines without gas powered equipment?
- roarcher 4y ago> Even though efficiency has improved, in 2016 California reported that just 1 hour of a gas-powered leaf blower was the equivalent of taking a Camry from LA to Denver. That cannot possibly be true. That's a 16 hour drive through 1000 miles of mountainous terrain, requiring multiple tanks of gas, vs an hour of a small two-stroke engine spinning a little turbine.
- gjsman-1000 4y agoAccording to the California Air Resources Board (CARB), it's true (except for CO2). https://ww2.arb.ca.gov/resources/fact-sheets/sore-small-engine-fact-sheet https://ww2.arb.ca.gov/resources/fact-sheets/sore-small-engi... @roarcher: They still emit lots of CO2 due to decreased efficiency, but the numbers aren't compared (so I'm not sure what they are), which I apologize for as I got CO2 confused with the other several gases being compared.
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- roarcher 4y ago> except for CO2 Considering this entire thread is only about CO2, not air quality, perhaps that would have been worth mentioning in your original comment.
- aksss 4y agoA leaf blower is about 11 lbs of CO2 per hour of use.[1] A car produces about a pound per mile. Let’s say that is +- 30% depending on variables of trip. [1] https://www.quietcleanpdx.org/wp-content/uploads/2019/11/Gas-Powered-Leaf-Blower-Emissions-Factsheet-11.12.pdf https://www.quietcleanpdx.org/wp-content/uploads/2019/11/Gas...
- roarcher 4y ago"per hour" vs "per mile" is an odd comparison. A car probably travels 60 miles in that hour.
- sbaiddn 4y agoNOT CO2 emissions Its worse in volatile organics, particulates and NOx. Mostly volatile organics due to the two stroke cycle. But not because a chainsaw is particularly bad, but because a Camry is exceptionally good. Why is the Camry good? Because it has a four stroke, fuel injected, computer controlled engine and $300 of catalysts breaking everything down. The smoke of the Camry's emissions is water condensing out.
- danans 4y ago> The smoke of the Camry's emissions is water condensing out. Not just water. A lot of CO, CO2, particulates and NOx are also emitted, especially at lower engine temperatures. https://www.sciencedirect.com/science/article/abs/pii/S0269749121009027 https://www.sciencedirect.com/science/article/abs/pii/S02697...
- sbaiddn 4y agoI was referring to smoke specifically the visually imposing clouds car produce which forms our image of car emissions. Of what you listed, only particulates add to the smokiness of a modern engine and then only when its cold. Unless its broken.
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- giantg2 4y agoTo be fair, they said new sidewalks, not necessarily concrete ones. There are some alternative materials out there. One major hurtle to using them is that the vast majority of places still require concrete in their codes.
- coxmichael 4y agoRoads were often made of wood blocks, so maybe that’s an option here too?
- giantg2 4y agoSomeone created a concrete replacement that I think consumes CO2 during curing. There's also brick, stone, etc.
- ericmay 4y agoYou know we have to build roads for the cars to drive on right? Wonder what the C02 emissions for a mile of new highway is. You're also not accounting for the construction, transportation, maintenance, and other CO2-producing activities for cars - none of which are necessary for walking. Nevermind the other benefits like attacking obesity and deaths due to car crashes. > 1. Get people into electric cars, which even on the current grid cuts your CO2 emissions by over half due to better efficiency, then > 2. Convert the electric grid to 100% clean energy. These both need to happen, yes. Cars existing is fine, just need to reduce usage for daily activities by 90% or so and also convert most of the grid to clean energy.
- revscat 4y ago> Cars existing is just fine I disagree with this sentiment. I hate cars, and what they have done to society. They are demonstrably and objectively not “fine”. They are the primary destructive force in society, and can and should die. Quickly.
- ericmay 4y agoI agree with your sentiment, but I'm not sure we'll get many people on board with "ban all cars". But we probably can get many people on board with something like, own only one car and stop wasting money on new highways and items like that. I think people can understand a world where they are walking to the grocery store and their car is for some random trip to the lake (one that ideally takes a bit longer with just two lane road and such). I'm not sure they'll be able to understand a world where cars don't even exist.
- notJim 4y agoI disagree on the absolutism in this. Cars can take you places that not many people want to go, and whenever you want, which is one of the coolest things a person can do. You're never going to build transit to all of these places, and it's too far to walk or bike. Used in this way, cars increase human freedom which is one of the most important values for humans to pursue. The real problem with cars is that we use them for everything. It makes zero sense for us to use cars in dense in cities, or between popular locales, or for short distances. We could probably eliminate more than 90% of car usage. But trying to eliminate cars period is too far.
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- thatfrenchguy 4y agoElectric cars emit a lot more than 0g/CO2 per mile, even in a perfect world. We need to get people out of car dependent suburbia, and it's going to be painful for a lot of Americans.
- Tade0 4y agoI see this mentioned a lot, but is there any plan?
- paulcole 4y agoNo, because people fundamentally don't want to do this. The plan exists now. Downsize your lifestyle drastically and move closer to the downtown of a major-ish city. But you suggest that to anyone and it's a litany of excuses for why this just won't work for them. The truth is that either they can't or they won't. And for the vast majority of people it's just that they won't.
- goatlover 4y agoThere's also only so much real-estate available fro major downtowns, and the prices will skyrocket if you could get "everyone" to want to move there.
- WorldMaker 4y agoBut that's a solvable problem. It's a chicken-and-egg problem, certainly, but if more people want to live in walkable "major downtowns", we could just, you know, build more walkable "major downtowns", not just inflate the prices of ones we already have. There's nothing really stopping us from building more cities or at least planning more suburban/exurban neighborhoods to be independently walkable and with enough amenities to be city-like other than status quo momentum and what remains of the current "American suburban dream" of single family detached homes and cars over public transportation and walking.
- thatfrenchguy 4y ago
- EGreg 4y agoWhy does building sidewalks need to take up so much CO2? And why can’t we use other forms of energy to power these machines w electricity?
- bloppe 4y agoThe chemical process of producing cement involves heating calcium carbonate to get lime and CO2. Most of the emissions are from this chemical process, not from transportation or operating machinery, although those usually also contribute quite a bit of CO2
- tcfhgj 4y agoWhy use cement and not cut stones, which live centuries?
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- than3 4y agoThe lithium needed for those electric cars far exceeds the same strategic resources currently on the planet afaik, electric cars won't work as a viable alternative.
- rolldat777 4y agoReproduced your calculation on the 1 million miles, it's surprising but checks out. Then consider how many miles of road we have already made and how much we continue to make to support large vehicles on them. You could designate half of them as car-free and induce alternative transportation if you really wanted to. OTOH, a new electric vehicle costs roughly 250k miles worth of driving to produce, without considering electricity generation.