• kurikai
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    386 months ago

    So bicycles are not a major form of transport?

    • DuskyRo
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      156 months ago

      Does it produce CO₂?

      • lad
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        426 months ago

        You’re breathing more intensely than usual, so there is some overhead. But then again walking would take longer and may produce more carbon overall for the same distance

        • Diplomjodler
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          266 months ago

          And don’t forget the methane from your farts.

        • @[email protected]
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          126 months ago

          I did some random calculations and with the assumption that cycling uses 300kcal/h @15km/h that makes it use about 20 kcal/km. Assuming it is burned by consuming carbohydrates(glucose)(4.5Kcal/g) and it converts 1:1 into CO2 that makes cycling emit about 5g CO2/km making it about as climate friendly as using eurostar trains.(assuming you dont want to exercise ever)

          • @[email protected]
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            56 months ago

            Hmm, thinking about it, I think maybe the direct CO2 exhaled during exercise may not be the most useful metric for human-powered travel. Every atom of that carbon was recently removed from the atmosphere by the plants you ate or that went to feed the animals you ate. It isn’t carbon that was underground for millions of years as is the case with fossil fuels.

            Unfortunately, growing the food does involve carbon emissions from fossil fuels. Taking this page’s number of 2.5t/yr for the typical American diet which they assume to be 2,600 kcal/day that works out to 2.6g of CO2 / kcal (2.5t / 365 / 2600 = 2.6E-6 t = 2.6g), or 52.7 g / km for cycling, or similar to an electric car if the chart is at all comparable (I don’t know the chart’s methodology; for example for the fossil fuel transport options does it count the carbon cost of producing and transporting the fuel or just the tailpipe emissions?). Changing one’s diet looks like it would improve this; the best-case would be a vegan diet which would result in 31.6 g / km.

            Now that’s just based on numbers from that one source, so I don’t know how reliable they are. It does say it includes the large amount of wasted food in the final number, and I don’t know if the numbers in the original chart are that level of conscientious. Regardless I think the takeaway here isn’t that cycling is bad, it’s that our food production system is terrible and it badly needs to become way less carbon-intensive.

        • @[email protected]
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          106 months ago

          Interestingly research actually shows electric bikes to have less of a carbon footprint than manual bikes even when accounting for the electricity, battery, motor, etc. due to the rider needing to consume fewer calories to provide the muscle power. But we’re talking numbers so small that it’s really not worth worrying about in the grander scheme of things. So if you’re feeling some guilt about the extra components in your ebike you don’t need to, but if you’re looking at an ebike to replace your regular one don’t make the decision purely based on carbon footprint, but instead focus on if you need/want it.

      • @[email protected]
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        86 months ago

        Yes, and food consumed from exertion. Simon Clarke actually did a really interesting video on bikes and ebikes and how good/bad they are for the environment, now and looking towards the future.

        https://youtu.be/HW5b8_KBtT8

        Tldw; a vegan on an ebike is one of the most energy efficient modes of transportation on the planet, haha.

        • @[email protected]
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          46 months ago

          I get what you meant but just to avoid any confusion, it’s not the most energy efficient but the one with the smallest carbon footprint.

          I assume that’s the case but I’ll watch the video and get back in case I’m wrong (I might not have left this comment if I wasn’t wont to forget about leaving a comment at all but people can reply and get me notified to update this in a day or two)