this post was submitted on 03 Mar 2024
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Discussion of climate, how it is changing, activism around that, the politics, and the energy systems change we need in order to stabilize things.

As a starting point, the burning of fossil fuels, and to a lesser extent deforestation and release of methane are responsible for the warming in recent decades: Graph of temperature as observed with significant warming, and simulated without added greenhouse gases and other anthropogentic changes, which shows no significant warming

How much each change to the atmosphere has warmed the world: IPCC AR6 Figure 2 - Thee bar charts: first chart: how much each gas has warmed the world.  About 1C of total warming.  Second chart:  about 1.5C of total warming from well-mixed greenhouse gases, offset by 0.4C of cooling from aerosols and negligible influence from changes to solar output, volcanoes, and internal variability.  Third chart: about 1.25C of warming from CO2, 0.5C from methane, and a bunch more in small quantities from other gases.  About 0.5C of cooling with large error bars from SO2.

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[–] [email protected] 65 points 9 months ago (1 children)

Based on this chart, electric car is a best way to burn calories

[–] [email protected] 10 points 9 months ago (1 children)

If you're charging it with your own muscles, sure. Or you could just put rocks in your panniers.

[–] [email protected] 9 points 9 months ago* (last edited 9 months ago) (1 children)

The joke is that calorie is a unit of energy, and it's the car that's "burning the calories" instead of your body

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[–] [email protected] 43 points 9 months ago (2 children)

Maybe the most surprising thing here is that regular biking is still twice as efficient as e-biking even given our mediocre metabolic efficiency and a physique that isn’t exactly designed for the bicycling motion.

[–] [email protected] 45 points 9 months ago* (last edited 9 months ago) (1 children)

it also has the Ebike going ~40% faster which means almost twice as much friction to overcome.

[–] [email protected] 25 points 9 months ago (2 children)

Seems to be meaningful that all of the speeds should be the same.

[–] [email protected] 6 points 9 months ago

To be meaningful, they should reflect the real-world imo. Which I they attempt to do? 18km/hr seems really slow for non-ebike (my last commute home by acoustic bike before I got an ebike was 27.0 km/hr), but I guess casual riders might go that speed?. If you use a class 3 ebike in the US, the ebike speed is also really slow (for class 1/2, its about right - I typically get 26km/hr). In Europe, speeds are typically less than the US for ebikes. And I think European urban speed limits tend to be less than US? Of course there's also traffic, so there are times when cars average less speed than bikes. Depending on location and time of year, how intensely the AC/heater in the car is running may significantly impact traffic fuel efficiency. They could have just included a few different speeds for each option, I suppose.

If you want to apply it to CO2, you need to convert that energy into CO2, but that's also really dependent on energy source. Coal power will be a lot worse than solar and wind. Typical US beef will be a lot worse than chicken or wheat or solar/wind energy. So, you would need a second chart and then do the calculations. For the average person whose ebike speed and acoustic bike speed are nearly the same, the ebike is better in terms of CO2. If someone gets specifically cleaner energy sources, then it would be a lot better. OTOH, someone connect to a grid that's mostly fossil fuels, but eats a low-CO2-emitting diet, the acoustic bike might be slightly better.

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[–] [email protected] 31 points 9 months ago (6 children)

Really had to drop that car speed down to make a meaningful chart huh?

[–] [email protected] 13 points 9 months ago (4 children)

Wdym? The faster a car moves (or anything, not just a car) the less efficient it's gonna be, because it has to fight against more and more wind resistance.

[–] [email protected] 41 points 9 months ago* (last edited 9 months ago) (5 children)

They're saying that at highway speeds the cars energy usage would be off the chart, or if they scaled the chart to that usage, everything else would be too small to discern the differences.

You guys are in agreement.

[–] [email protected] 13 points 9 months ago

Aaah, I get it now, thanks!

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[–] [email protected] 6 points 9 months ago

The measure of productivity of transportation is distance traveled, not speed (unless this were some time race). Comparing kw/speed tells you nothing about the kWh used to make the same trip as alternative modes of transportation.

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[–] sukhmel 9 points 9 months ago

Besides the other comment being right about air resistance, a speed of around 40 km/h is considered safe in urban environments and artificial obstacles are now being placed to lower traffic speed to about that limit. Also, the mean speed is also around that in towns where you either go faster than the limit or go 0 in a traffic jam

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[–] [email protected] 30 points 9 months ago (1 children)

Looks like trains are about 50wh/km

https://www.linkedin.com/pulse/most-energy-efficient-mode-zero-emission-urban-transport-kme%C5%A5

I couldn't find any info on planes, but that'd be interesting to see how massive that would be too.

[–] [email protected] 12 points 9 months ago (2 children)

It's that normalized by passenger or is that just the train?

[–] [email protected] 16 points 9 months ago (3 children)

Normalized by passenger, certainly. However, it's easier to hit passenger capacity in a train than in a (private) car.

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[–] [email protected] 6 points 9 months ago

The 50 is normalized to passenger. I think it's 30 per seat, but I guess they don't fill all the seats usually.

[–] [email protected] 29 points 9 months ago (9 children)

Yeah, micro mobility is great on paper when you’re young and live in an accessible city with flat topography. Years ago I became (and still am) a bicycle commuter and I am ENTIRELY SICK OF IT. I want a fucking car. I am tired of biking in the rain and the snow and the cold. It fucking sucks.

Also If I didnt have the ability to purchase an e-bike recently I’d be fucked with the terrain of the place I am currently stuck living (and even that doesn’t quite cover the situation).

Also I am tired of minor injuries compounding year over year due to the simple fact that I am using my body as both the engine and support structure to move myself, vehicle and cargo around just to live.

It was fun 10 years ago but now I’m just like give me a fucking cargo van.

[–] [email protected] 16 points 9 months ago* (last edited 9 months ago) (1 children)

I've been telling everyone how most people don't need a car in a big enough city (I'm in Europe), and how much more efficient (PROPER) public transport is.

...And then I get the work commute metro trains where stupid/inconsiderate/disgusting people still get on the packed train despite being sick, keep standing in my kidney and sneeze/cough at others (without a mask, of course) and sniff their nose all the way. Every single time when that happens I dream about having my own car where I don't have to deal with this (or an idiot blasting TikTok from their speakers, being drunk+loud, smelly, etc.).

I still won't have a car, but man, sometimes the right decision isn't the easiest.

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[–] [email protected] 9 points 9 months ago (5 children)
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[–] [email protected] 6 points 9 months ago (1 children)

Had a neighbour in his 80, had multiple leg operations and he still used to take a daily bike ride to keep fit. Not to mention that even if bike commutes suck, they improve your mental health considerably, even if you go in the rain/cold.

And most importantly of all, those who can take the bike cover those who can't. So please enjoy your car ride, but take the bike when you can.

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[–] [email protected] 22 points 9 months ago* (last edited 9 months ago) (4 children)

The car is correctly represented, about 0.15 KWh / km is what one gets.

However, the positioning of the e-bike looks strange to me. I've looked at previous studies and the e-biker has always been first in efficiency - because the efficiency of a motor far exceeds the efficiency of human digestion and muscles, while weight and speed remain comparable to an ordinary cyclist.

I think someone has calculated food energy incorrectly, or assumed that e-bikes move faster than they do. :)

[–] [email protected] 6 points 9 months ago (2 children)

I guess it's hard to gauge an e-bike since they often have a variety of operating modes ranging from progressively higher levels of pedal assist up to full throttle. But that's fascinating to think that an all-electric ride may actual consume less energy in the grand scheme of things. I had never looked at it that way!

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[–] [email protected] 20 points 9 months ago* (last edited 9 months ago) (5 children)

This would be much more efficient if it had other transportation as well.

Like non-electric cars, trains, subways, etc.

It's not too hard to get their efficiency as well.

NEXT DAY EDIT: Should've looked, there's actually a handy chart showing the energy efficiencies of a whole bunch of vehicles and modes of transport just straight up on Wikipedia. This article. Comparing the km/MJ column, we can see:

Walking 4.55

Velomobile with enclosed recumbent: 12.35 (there wasnt a figure for just regular biking)

Solar car: 14.93

Tesla Model 3: 1.76

General Motors EV1: 1.21

All combustion engines are below 1, but here's a few:

VW Passat: 0.33 Cadillac CTS-V: 0.17 Renault Clio: 0.42

There's a whole bunch of other stats though so I suggest checking the table

END EDIT

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[–] [email protected] 19 points 9 months ago (1 children)

While I like this chart, it's useless without the tradeoff. It also needs to map speed to time spent. What is being given up for improved efficiency? The inflection point is how you move people from point A to point B.

[–] [email protected] 12 points 9 months ago

The biggie is urban planning to ensure that people don't need to travel huge distances on a routine basis. That means that people give up very little.

[–] [email protected] 19 points 9 months ago (2 children)

This should be shown in Km/Wh so the more efficient the modes of travel show as bigger bars.

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[–] [email protected] 17 points 9 months ago (2 children)

This data needs to be normalized by speed or realistic range/day. Otherwise it's pretty meaningless.

[–] [email protected] 11 points 9 months ago

It is totally pointless, I am totally on side of bikes and walkable cities, but this chart is pointless. What battery stores and what humans use is not comparable, and adding combustion engine car/bus/train here would throw the chart to totally other scale. Train has enough kWh to power a small town, but it carries shit ton of load.

[–] [email protected] 5 points 9 months ago (4 children)

Like most "fuck cars" memes it's only relevant if you're a young single person with no hobbies who never travels more than 5km from their home without taking public transport.

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[–] [email protected] 15 points 9 months ago* (last edited 9 months ago) (2 children)

Energy efficiency and carbon footprint are very different things - pretty sure the carbon footprint of 15 big macs (8500kcal) is substantially greater than 1L of gasoline (let alone an electric grid equivalent)

[–] [email protected] 5 points 9 months ago* (last edited 9 months ago) (3 children)

A quick googling tells me a burger is about 3kg of CO2 equivalents. 1L of gas seems to be about 2,5kg.

Now if you were to eat local and seasonal food I'd guess you can get more efficient than burning oil.

Edit: As @bjorney correctly pointed out a quick google in the morning, before the brain functions properly kick in, isn't the best way to produce comments on numbers. I did NOT account for the factor of about 15 that a burger needs to get close the energy stored in a liter of gasoline.

Edit to the edit: Just out of curiosity I did another quick google (please brain, be functioning now) and it seems that to get 8500kcal from oats you need about 2,5kg. This seems to produce about 1kg of co2 equivalents. I am certain that this does not include the amount of co2 the human is expelling in excess by using their muscles instead of a motor, so the whole discussion is probably moot anyways.

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[–] [email protected] 15 points 9 months ago* (last edited 9 months ago) (3 children)

Now do one where you A) normalize this to the same trip distance (not speed, so that these choices for a single trip become meaningfull) and B) convert the kWh into CO2 emissions, including the emissions in growing and transporting the various power and food production methods used (coal to solar, locally produced veggies-air shipped beef)

[–] [email protected] 13 points 9 months ago* (last edited 9 months ago)

It's already normalized to distance, the graph is showing kWh/km. The speed is just there for additional context.

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[–] [email protected] 14 points 9 months ago

Interesting. I've never owned an electric car, but just guesstimating based on those numbers, my daily commute would cost something like 25 cents in electricity. Not too shabby.

I did buy an ebike a few years back and watched to see how much the bill went up, but frankly never noticed any change. At 2 cents per day, it's basically a rounding error relative to other electrical usage, so that makes sense to me now.

[–] [email protected] 13 points 9 months ago (6 children)

Let me just travel 30km to the shops by foot and carry shopping home another 30km back again

[–] [email protected] 10 points 9 months ago* (last edited 9 months ago) (9 children)

Have you heard of this miraculous thing called public transit? And there are things called panniers which are pretty cool too.

But frankly, if you don't have groceries within walking distance, your neighborhood and your zoning laws are very poorly designed.

And that's deliberate. Neighborhoods around the world are designed to require cars to live in, because of oil company lobbying, and also for "security", in order to keep out people too poor to own cars.

Getting rid of cars requires changing the various ways our cities are designed to make cars necessary. That's worth doing too.

[–] [email protected] 12 points 9 months ago

Living outside land of the free, I have like 4 grocery stores and 1 supermarket within 15min walking distance, and I don't live in a dense neighborhood.

[–] [email protected] 7 points 9 months ago (1 children)
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[–] [email protected] 8 points 9 months ago (3 children)

That means the urban planning in your area is garbage. That is fixable and has to be fixed.

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[–] [email protected] 12 points 9 months ago (1 children)

Thanks a lot for linking the source!

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[–] [email protected] 11 points 9 months ago (2 children)

Where's the gas car on here? How about steam locomotive?

If I've got to go 300+ miles through the US I'm probably not going on foot or by human power.

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[–] [email protected] 9 points 9 months ago (1 children)

EBikes are awesome. I live in a hilly area where riding is tough. EBikes allows people of all ages and abilities to get out. Even with the assistance you still burn calories... as long as it's assisted peddling and not the illegal bikes I see delivery guys riding.

I ride road bikes but when I get older and less capable I'll certainly invest in an ebike.

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[–] [email protected] 9 points 9 months ago

This should include gas cars too which are ungodly inefficient

[–] [email protected] 5 points 9 months ago (3 children)
[–] [email protected] 10 points 9 months ago (4 children)

I believe most e-bikes in Europe are limited to 25km/h. 32km/h in Canada.

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[–] [email protected] 5 points 9 months ago (3 children)

Cool, now do the same chart but instead of energy use time.

[–] [email protected] 12 points 9 months ago (1 children)

Time efficiency in a modern urban area optimized for public transport and non-motorized transport modes compared to time efficiency in current typical urban areas, which are focused on individual motorized transport modes with severe lack of public transport:

[Fancy chart: first case left, second case right]

[Good] [Bad]

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