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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[–] hemko@lemmy.dbzer0.com 65 points 8 months ago (1 children)

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

[–] silence7@slrpnk.net 10 points 8 months ago (1 children)

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

[–] hemko@lemmy.dbzer0.com 9 points 8 months ago* (last edited 8 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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[–] will_a113@lemmy.ml 43 points 8 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.

[–] Womble@lemmy.world 45 points 8 months ago* (last edited 8 months ago) (1 children)

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

[–] Kbobabob@lemmy.world 25 points 8 months ago (2 children)

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

[–] WalrusDragonOnABike@reddthat.com 6 points 8 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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[–] I_Has_A_Hat@lemmy.world 31 points 8 months ago (6 children)

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

[–] highduc@lemmy.ml 13 points 8 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.

[–] Fermion@mander.xyz 41 points 8 months ago* (last edited 8 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.

[–] highduc@lemmy.ml 13 points 8 months ago

Aaah, I get it now, thanks!

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[–] SkyNTP@lemmy.ml 6 points 8 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@programming.dev 9 points 8 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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[–] JohnDClay@sh.itjust.works 30 points 8 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.

[–] huginn@feddit.it 12 points 8 months ago (2 children)

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

[–] federalreverse@feddit.de 16 points 8 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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[–] JohnDClay@sh.itjust.works 6 points 8 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.

[–] Donebrach@lemmy.world 29 points 8 months ago (8 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.

[–] Dicska@lemmy.world 16 points 8 months ago* (last edited 8 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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[–] abuttandahalf@lemmy.ml 9 points 8 months ago (5 children)
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[–] heartpatcher@lemmy.world 6 points 8 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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[–] stabby_cicada@slrpnk.net 5 points 8 months ago (1 children)

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.

I'm sorry you're getting pushback and criticism for this. As someone who physically can't bicycle and struggles with mobility, I strongly support well designed and well maintained walkable communities, bicycle infrastructure, and effective public transit. And I recognize that, for some people, the basic right to travel and work and generally function in society requires personal car ownership.

That doesn't mean I sympathize much with people who live in subdivisions off major highways with no grocery stories within twenty miles - there shouldn't be any community anywhere designed to require car ownership.

But I also don't sympathize much with people who want to ban all personal vehicle ownership from their little 15 minute utopias. Disabled people exist.

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[–] perestroika@slrpnk.net 22 points 8 months ago* (last edited 8 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. :)

[–] tunetardis@lemmy.ca 6 points 8 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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[–] Dasus@lemmy.world 20 points 8 months ago* (last edited 8 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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[–] fmstrat@lemmy.nowsci.com 19 points 8 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.

[–] silence7@slrpnk.net 12 points 8 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.

[–] dylanmorgan@slrpnk.net 19 points 8 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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[–] Aedis@lemmy.world 17 points 8 months ago (2 children)

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

[–] Hotzilla@sopuli.xyz 11 points 8 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.

[–] fine_sandy_bottom@discuss.tchncs.de 5 points 8 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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[–] bjorney@lemmy.ca 15 points 8 months ago* (last edited 8 months ago) (5 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)

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[–] SkyNTP@lemmy.ml 15 points 8 months ago* (last edited 8 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)

[–] vithigar@lemmy.ca 13 points 8 months ago* (last edited 8 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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[–] tunetardis@lemmy.ca 14 points 8 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.

[–] ryannathans@aussie.zone 13 points 8 months ago (6 children)

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

[–] stabby_cicada@slrpnk.net 10 points 8 months ago* (last edited 8 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.

[–] Allero@lemmy.today 12 points 8 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.

[–] ryannathans@aussie.zone 7 points 8 months ago (1 children)
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[–] abuttandahalf@lemmy.ml 8 points 8 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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[–] Zacryon@feddit.de 12 points 8 months ago (1 children)

Thanks a lot for linking the source!

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[–] dream_weasel@sh.itjust.works 11 points 8 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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[–] Dippy@beehaw.org 9 points 8 months ago

This should include gas cars too which are ungodly inefficient

[–] Swarfega@lemm.ee 9 points 8 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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[–] Scrof@sopuli.xyz 5 points 8 months ago (3 children)
[–] thatsnothowyoudoit@lemmy.ca 10 points 8 months ago (4 children)

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

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